外汇EA编写教程：轻松快捷开发 MetaTrader 程序的函数库（第 二十九部分）：延后交易请求 – 请求对象类

内容

• 概念
• 抽象延后交易请求的基准对象
• 延后请求基准对象的衍生对象
• 测试
• 下一步是什么？

概念

在前三篇文章里，我们检验了利用延后请求管理交易类交易方法的概念。
实际上，延后请求是由特定条件执行的正常交易订单。 当收到服务器错误时，若该处理错误需要一些等待时间才能重新发送请求至服务器，则我们在交易方法里会检查延迟发送交易订单的条件。 自然而然，并非所有条件都能适用于延后请求。 条件还可以包括价位，触及该价位则发送交易订单。 它也可以是条件的组合，例如p品种属性的某些阈值。 触及这些阈值后，交易订单会被发送到服务器（stoplimit 挂单是一个很好的延后交易请求示例，当价格触及止价位时下一笔限价挂单）。

通常，延后交易请求令我们能够创建某种行为逻辑，从而将交易订单发送至服务器。

然而，为令所有这些能适合延后请求对象代码，我们需要它遵从函数库对象的常规概念。 这会令对象易于扩展，以便在其中插入新属性。 当前阶段，处理延后交易请求的代码直接位于交易类清单中。 这样做纯粹是为了验证概念，若在概念上不正确，则无法进一步使用。 我有意这样做，出于在将结构包装成正确的形式之前，快速验证所有内容。
在当前文章中，我们会创建抽象延后交易请求对象的基类，和基准请求对象的衍生对象类。 基准对象将包含请求对象共有的所有属性，而衍生对象则包含每个子对象状态的独有原生属性。 所有函数库对象都已完成了此操作，且当前状况也会不例外。

但是首先，如往常一样，我们创建处理该对象所需的函数库消息。

在 Datas.mqh 文件中写入新的函数库消息索引：

…

   MSG_LIB_TEXT_AND_PAUSE,                            //  and pause 
   MSG_LIB_TEXT_ALREADY_EXISTS,                       // already exists
   MSG_LIB_TEXT_CREATED,                              // Created
   MSG_LIB_TEXT_ATTEMPTS,                             // Attempts
   MSG_LIB_TEXT_WAIT,                                 // Wait
   MSG_LIB_TEXT_END,                                  // End

…

   MSG_LIB_TEXT_REQUEST,                              // Pending request #
   MSG_LIB_TEXT_REQUEST_DATAS,                        // Trading request parameters
   MSG_LIB_TEXT_PEND_REQUEST_DATAS,                   // Pending trading request parameters

…

   MSG_LIB_TEXT_PEND_REQUEST_BY_ERROR,                // Pending request generated based on the server return code
   MSG_LIB_TEXT_PEND_REQUEST_BY_REQUEST,              // Pending request created by request
   MSG_LIB_TEXT_PEND_REQUEST_WAITING_ONSET,           // Wait for the first trading attempt
   
   MSG_LIB_TEXT_PEND_REQUEST_STATUS,                  // Pending request status
   MSG_LIB_TEXT_PEND_REQUEST_STATUS_OPEN,             // Pending request to open a position
   MSG_LIB_TEXT_PEND_REQUEST_STATUS_CLOSE,            // Pending request to close a position
   MSG_LIB_TEXT_PEND_REQUEST_STATUS_SLTP,             // Pending request to modify position stop orders
   MSG_LIB_TEXT_PEND_REQUEST_STATUS_PLACE,            // Pending request to place a pending order
   MSG_LIB_TEXT_PEND_REQUEST_STATUS_REMOVE,           // Pending request to delete a pending order
   MSG_LIB_TEXT_PEND_REQUEST_STATUS_MODIFY,           // Pending request to modify pending order parameters
  };

以及与新索引相对应的消息：

   {" и паузой "," and pause "},
   {" уже существует"," already exists"},
   {"Создан","Created"},
   {"Попыток","Attempts"},
   {"Ожидание","Wait"},
   {"Окончание","End"},

…

   {"Отложенный запрос #","Pending request #"},
   {"Параметры торгового запроса","Trade request parameters"},
   {"Параметры отложенного торгового запроса","Pending trade request parameters"},

…

   {"Отложенный запрос, созданный по коду возврата сервера","Pending request created as a result of server code"},
   {"Отложенный запрос, созданный по запросу","Pending request created by request"},
   {"Ожидание наступления времени первой торговой попытки","Waiting for onset time of the first trading attempt"},
   
   {"Статус отложенного запроса","Pending request status"},
   {"Отложенный запрос на открытие позиции","Pending request to open position"},
   {"Отложенный запрос на закрытие позиции","Pending request to close position"},
   {"Отложенный запрос на модификацию стоп-приказов позиции","Pending request to modify position stop orders"},
   {"Отложенный запрос на установку отложенного ордера","Pending request to place pending order"},
   {"Отложенный запрос на удаление отложенного ордера","Pending request to remove pending order"},
   {"Отложенный запрос на модификацию параметров отложенного ордера","Pending request to modify pending order parameters"},
  };

如上所述，延后交易请求的基准对象是一个通用抽象请求，其中包含所有交易请求中存在的属性，而厘清属性的任务则分派给基准对象的衍生对象。
因此，我们将有一个基准请求对象和六个衍生对象，它们按照执行的交易操作的类型来厘清延后请求的属性：

• 开仓（对冲账户上的一笔新仓，而在净持账户上则是加仓和冲抵）；
• 修改持仓的止价单；
• 平仓 — 全部和部分平仓，及以逆向订单平仓（在对冲账户上）；
  
• 下挂单;
• 修改挂单属性 — 止价单价位，下单价位，StopLimit 挂单价位，订单生存期，填充类型和到期类型；
• 删除之前下达的挂单。

抽象延后交易请求的基准对象

我们创建延后交易请求对象属性的枚举，就像所有先前的函数库对象一样。

在 Defines.mqh 文件里，加入对象状态枚举，以及整数型，实数型 和字符串型属性:

//+------------------------------------------------------------------+
//| Data for working with pending trading requests                   |
//+------------------------------------------------------------------+
//+------------------------------------------------------------------+
//| Pending request status                                           |
//+------------------------------------------------------------------+
enum ENUM_PEND_REQ_STATUS
  {
   PEND_REQ_STATUS_OPEN,                                    // Pending request to open a position
   PEND_REQ_STATUS_CLOSE,                                   // Pending request to close a position
   PEND_REQ_STATUS_SLTP,                                    // Pending request to modify open position stop orders
   PEND_REQ_STATUS_PLACE,                                   // Pending request to place a pending order
   PEND_REQ_STATUS_REMOVE,                                  // Pending request to delete a pending order
   PEND_REQ_STATUS_MODIFY                                   // Pending request to modify a placed pending order
  };
//+------------------------------------------------------------------+
//| Pending request type                                             |
//+------------------------------------------------------------------+
enum ENUM_PEND_REQ_TYPE
  {
   PEND_REQ_TYPE_ERROR=PENDING_REQUEST_ID_TYPE_ERR,         // Pending request created based on the return code or error
   PEND_REQ_TYPE_REQUEST=PENDING_REQUEST_ID_TYPE_REQ,       // Pending request created by request
  };
//+------------------------------------------------------------------+
//| Integer properties of a pending trading request                  |
//+------------------------------------------------------------------+
enum ENUM_PEND_REQ_PROP_INTEGER
  {
   PEND_REQ_PROP_STATUS = 0,                                // Trading request status (from the ENUM_PEND_REQ_STATUS enumeration)
   PEND_REQ_PROP_TYPE,                                      // Trading request type (from the ENUM_PEND_REQ_TYPE enumeration)
   PEND_REQ_PROP_ID,                                        // Trading request ID
   PEND_REQ_PROP_RETCODE,                                   // Result a request is based on
   PEND_REQ_PROP_TIME_CREATE,                               // Request creation time
   PEND_REQ_PROP_TIME_ACTIVATE,                             // Next attempt activation time
   PEND_REQ_PROP_WAITING,                                   // Waiting time between requests
   PEND_REQ_PROP_CURENT,                                    // Current attempt index
   PEND_REQ_PROP_TOTAL,                                     // Number of attempts
   //--- MqlTradeRequest
   PEND_REQ_PROP_MQL_REQ_ACTION,                            // Type of a performed action in the request structure
   PEND_REQ_PROP_MQL_REQ_TYPE,                              // Order type in the request structure
   PEND_REQ_PROP_MQL_REQ_MAGIC,                             // EA stamp (magic number ID) in the request structure
   PEND_REQ_PROP_MQL_REQ_ORDER,                             // Order ticket in the request structure
   PEND_REQ_PROP_MQL_REQ_POSITION,                          // Position ticket in the request structure
   PEND_REQ_PROP_MQL_REQ_POSITION_BY,                       // Opposite position ticket in the request structure
   PEND_REQ_PROP_MQL_REQ_DEVIATION,                         // Maximum acceptable deviation from a requested price in the request structure
   PEND_REQ_PROP_MQL_REQ_EXPIRATION,                        // Order expiration time (for ORDER_TIME_SPECIFIED type orders) in the request structure
   PEND_REQ_PROP_MQL_REQ_TYPE_FILLING,                      // Order filling type in the request structure
   PEND_REQ_PROP_MQL_REQ_TYPE_TIME,                         // Order lifetime type in the request structure
  }; 
#define PEND_REQ_PROP_INTEGER_TOTAL (19)                    // Total number of integer event properties
#define PEND_REQ_PROP_INTEGER_SKIP  (0)                     // Number of request properties not used in sorting
//+------------------------------------------------------------------+
//| Real properties of a pending trading request                     |
//+------------------------------------------------------------------+
enum ENUM_PEND_REQ_PROP_DOUBLE
  {
   PEND_REQ_PROP_PRICE_CREATE = PEND_REQ_PROP_INTEGER_TOTAL,// Price at the moment of a request generation
   //--- MqlTradeRequest
   PEND_REQ_PROP_MQL_REQ_VOLUME,                            // Requested volume of a deal in lots in the request structure
   PEND_REQ_PROP_MQL_REQ_PRICE,                             // Price in the request structure
   PEND_REQ_PROP_MQL_REQ_STOPLIMIT,                         // StopLimit level in the request structure
   PEND_REQ_PROP_MQL_REQ_SL,                                // Stop Loss level in the request structure
   PEND_REQ_PROP_MQL_REQ_TP,                                // Take Profit level in the request structure
  };
#define PEND_REQ_PROP_DOUBLE_TOTAL  (6)                     // Total number of event's real properties
#define PEND_REQ_PROP_DOUBLE_SKIP   (0)                     // Number of order properties not used in sorting
//+------------------------------------------------------------------+
//| String properties of a pending trading request                   |
//+------------------------------------------------------------------+
enum ENUM_PEND_REQ_PROP_STRING
  {
   //--- MqlTradeRequest
   PEND_REQ_PROP_MQL_REQ_SYMBOL = (PEND_REQ_PROP_INTEGER_TOTAL+PEND_REQ_PROP_DOUBLE_TOTAL),  // Trading instrument name in the request structure
   PEND_REQ_PROP_MQL_REQ_COMMENT                            // Order comment in the request structure
  };
#define PEND_REQ_PROP_STRING_TOTAL  (2)                     // Total number of event's string properties
//+------------------------------------------------------------------+

指定每种属性类型之数量的宏替换用于计算属性在对象属性数组中的索引。
在阐述函数库生成时，我们已经在第一篇文章中研究过这些。 在此复述没有任何意义。

如我们从清单中所见，对象属性既包括属于延后请求创建的参数，也有在 MqlTradeRequest 交易请求结构中指定的属性，其中所有发送给服务器的请求参数均被预设。
由于我们要按其任何参数对列表中的对象进行排序和搜索（就像所有先前的函数库对象一样），我们重复结构字段的用途，将交易请求结构的整个内容复制到相应的对象属性中。 在这种情况下，我们可以按任何属性在列表中查找并排序延后请求。

为了搜索和排序延后请求对象，列出所有可能的对象排序条件：

//+------------------------------------------------------------------+
//| Possible pending request sorting criteria                        |
//+------------------------------------------------------------------+
#define FIRST_PREQ_DBL_PROP         (PEND_REQ_PROP_INTEGER_TOTAL-PEND_REQ_PROP_INTEGER_SKIP)
#define FIRST_PREQ_STR_PROP         (PEND_REQ_PROP_INTEGER_TOTAL-PEND_REQ_PROP_INTEGER_SKIP+PEND_REQ_PROP_DOUBLE_TOTAL-PEND_REQ_PROP_DOUBLE_SKIP)
enum ENUM_SORT_PEND_REQ_MODE
  {
//--- Sort by integer properties
   SORT_BY_PEND_REQ_STATUS = 0,                             // Sort by a trading request status (from the ENUM_PEND_REQ_STATUS enumeration)
   SORT_BY_PEND_REQ_TYPE,                                   // Sort by a trading request type (from the ENUM_PEND_REQ_TYPE enumeration)
   SORT_BY_PEND_REQ_ID,                                     // Sort by a trading request ID
   SORT_BY_PEND_REQ_RETCODE,                                // Sort by a result a request is based on
   SORT_BY_PEND_REQ_TIME_CREATE,                            // Sort by a request generation time
   SORT_BY_PEND_REQ_TIME_ACTIVATE,                          // Sort by next attempt activation time
   SORT_BY_PEND_REQ_WAITING,                                // Sort by a waiting time between requests
   SORT_BY_PEND_REQ_CURENT,                                 // Sort by the current attempt index
   SORT_BY_PEND_REQ_TOTAL,                                  // Sort by a number of attempts
   //--- MqlTradeRequest
   SORT_BY_PEND_REQ_MQL_REQ_ACTION,                         // Sort by a type of a performed action in the request structure
   SORT_BY_PEND_REQ_MQL_REQ_TYPE,                           // Sort by an order type in the request structure
   SORT_BY_PEND_REQ_MQL_REQ_MAGIC,                          // Sort by an EA stamp (magic number ID) in the request structure
   SORT_BY_PEND_REQ_MQL_REQ_ORDER,                          // Sort by an order ticket in the request structure
   SORT_BY_PEND_REQ_MQL_REQ_POSITION,                       // Sort by a position ticket in the request structure
   SORT_BY_PEND_REQ_MQL_REQ_POSITION_BY,                    // Sort by an opposite position ticket in the request structure
   SORT_BY_PEND_REQ_MQL_REQ_DEVIATION,                      // Sort by a maximum acceptable deviation from a requested price in the request structure
   SORT_BY_PEND_REQ_MQL_REQ_EXPIRATION,                     // Sort by an order expiration time (for ORDER_TIME_SPECIFIED type orders) in the request structure
   SORT_BY_PEND_REQ_MQL_REQ_TYPE_FILLING,                   // Sort by an order filling type in the request structure
   SORT_BY_PEND_REQ_MQL_REQ_TYPE_TIME,                      // Sort by order lifetime type in the request structure
//--- Sort by real properties
   SORT_BY_PEND_REQ_PRICE_CREATE = FIRST_PREQ_DBL_PROP,     // Sort by a price at the moment of a request generation
   //--- MqlTradeRequest
   SORT_BY_PEND_REQ_MQL_REQ_VOLUME,                         // Sort by a requested volume of a deal in lots in the request structure
   SORT_BY_PEND_REQ_MQL_REQ_PRICE,                          // Sort by a price in the request structure
   SORT_BY_PEND_REQ_MQL_REQ_STOPLIMIT,                      // Sort by StopLimit order level in the request structure
   SORT_BY_PEND_REQ_MQL_REQ_SL,                             // Sort by StopLoss order level in the request structure
   SORT_BY_PEND_REQ_MQL_REQ_TP,                             // Sort by TakeProfit order level in the request structure
//--- Sort by string properties
   //--- MqlTradeRequest
   SORT_BY_PEND_REQ_MQL_SYMBOL = FIRST_PREQ_STR_PROP,       // Sort by a trading instrument name in the request structure
   SORT_BY_PEND_REQ_MQL_COMMENT                             // Sort by an order comment in the request structure
  };
//+------------------------------------------------------------------+

在一个单独的文件中，创建一个抽象的延后请求基准对象的新类。

在 /MQL5/Include/DoEasy/Objects/ 函数库目录里，创建一个新的 PendRequest/ 子目录，存储延后交易请求的类文件。

在 PendRequest 文件夹的 PendRequest.mqh 文件里创建一个抽象的延后请求基准对象的新类：

//+------------------------------------------------------------------+
//|                                                  PendRequest.mqh |
//|                        Copyright 2019, MetaQuotes Software Corp. |
//|                             https://mql5.com/en/users/artmedia70 |
//+------------------------------------------------------------------+
#property copyright "Copyright 2019, MetaQuotes Software Corp."
#property link      "https://mql5.com/en/users/artmedia70"
#property version   "1.00"
#property strict    // Necessary for mql4
//+------------------------------------------------------------------+
//| Include files                                                    |
//+------------------------------------------------------------------+
#include <Object.mqh>
#include "../../Services/DELib.mqh"
//+------------------------------------------------------------------+
//| Abstract pending trading request class                           |
//+------------------------------------------------------------------+
class CPendRequest : public CObject
  {
private:
   MqlTradeRequest   m_request;                                         // Trade request structure
//--- Copy trading request data
   void              CopyRequest(const MqlTradeRequest &request);
//--- Return the index of the array the request (1) double and (2) string properties are actually located at
   int               IndexProp(ENUM_PEND_REQ_PROP_DOUBLE property)const { return(int)property-PEND_REQ_PROP_INTEGER_TOTAL;                               }
   int               IndexProp(ENUM_PEND_REQ_PROP_STRING property)const { return(int)property-PEND_REQ_PROP_INTEGER_TOTAL-PEND_REQ_PROP_DOUBLE_TOTAL;    }
protected:
   int               m_digits;                                          // Number of decimal places in a quote
   int               m_digits_lot;                                      // Number of decimal places in the symbol lot value
   bool              m_is_hedge;                                        // Hedging account flag
   long              m_long_prop[PEND_REQ_PROP_INTEGER_TOTAL];          // Request integer properties
   double            m_double_prop[PEND_REQ_PROP_DOUBLE_TOTAL];         // Request real properties
   string            m_string_prop[PEND_REQ_PROP_STRING_TOTAL];         // Request string properties
//--- Protected parametric constructor
                     CPendRequest(const ENUM_PEND_REQ_STATUS status,
                                  const uchar id,
                                  const double price,
                                  const ulong time,
                                  const MqlTradeRequest &request,
                                  const int retcode);
//--- Return (1) the magic number specified in the settings, (2) hedging account flag
   ushort            GetMagicID(void)                                      const { return ushort(this.GetProperty(PEND_REQ_PROP_MQL_REQ_MAGIC) & 0xFFFF);}
   bool              IsHedge(void)                                         const { return this.m_is_hedge;                                               }
public:
//--- Default constructor
                     CPendRequest(){;}
//--- Set request (1) integer, (2) real and (3) string properties
   void              SetProperty(ENUM_PEND_REQ_PROP_INTEGER property,long value) { this.m_long_prop[property]=value;                                     }
   void              SetProperty(ENUM_PEND_REQ_PROP_DOUBLE property,double value){ this.m_double_prop[this.IndexProp(property)]=value;                   }
   void              SetProperty(ENUM_PEND_REQ_PROP_STRING property,string value){ this.m_string_prop[this.IndexProp(property)]=value;                   }
//--- Return (1) integer, (2) real and (3) string request properties from the properties array
   long              GetProperty(ENUM_PEND_REQ_PROP_INTEGER property)      const { return this.m_long_prop[property];                                    }
   double            GetProperty(ENUM_PEND_REQ_PROP_DOUBLE property)       const { return this.m_double_prop[this.IndexProp(property)];                  }
   string            GetProperty(ENUM_PEND_REQ_PROP_STRING property)       const { return this.m_string_prop[this.IndexProp(property)];                  }

//--- Return the flag of the request supporting the property
   virtual bool      SupportProperty(ENUM_PEND_REQ_PROP_INTEGER property)        { return true; }
   virtual bool      SupportProperty(ENUM_PEND_REQ_PROP_DOUBLE property)         { return true; }
   virtual bool      SupportProperty(ENUM_PEND_REQ_PROP_STRING property)         { return true; }

//--- Compare CPendRequest objects by a specified property (to sort the lists by a specified request object property)
   virtual int       Compare(const CObject *node,const int mode=0) const;
//--- Compare CPendRequest objects by all properties (to search for equal request objects)
   bool              IsEqual(CPendRequest* compared_obj);
   
//+------------------------------------------------------------------+
//| Methods of a simplified access to the request object properties  |
//+------------------------------------------------------------------+
//--- Return (1) request structure, (2) status, (3) type, (4) price at the moment of the request generation,
//--- (5) request generation time, (6) next attempt activation time,
//--- (7) waiting time between requests, (8) current attempt index,
//--- (9) number of attempts, (10) request ID
//--- (11) result a request is based on,
//--- (12) order ticket, (13) position ticket, (14) trading operation type
   MqlTradeRequest      MqlRequest(void)                                   const { return this.m_request;                                                }
   ENUM_PEND_REQ_STATUS Status(void)                                       const { return (ENUM_PEND_REQ_STATUS)this.GetProperty(PEND_REQ_PROP_STATUS);  }
   ENUM_PEND_REQ_TYPE   TypeRequest(void)                                  const { return (ENUM_PEND_REQ_TYPE)this.GetProperty(PEND_REQ_PROP_TYPE);      }
   double               PriceCreate(void)                                  const { return this.GetProperty(PEND_REQ_PROP_PRICE_CREATE);                  }
   ulong                TimeCreate(void)                                   const { return this.GetProperty(PEND_REQ_PROP_TIME_CREATE);                   }
   ulong                TimeActivate(void)                                 const { return this.GetProperty(PEND_REQ_PROP_TIME_ACTIVATE);                 }
   ulong                WaitingMSC(void)                                   const { return this.GetProperty(PEND_REQ_PROP_WAITING);                       }
   uchar                CurrentAttempt(void)                               const { return (uchar)this.GetProperty(PEND_REQ_PROP_CURENT);                 }
   uchar                TotalAttempts(void)                                const { return (uchar)this.GetProperty(PEND_REQ_PROP_TOTAL);                  }
   uchar                ID(void)                                           const { return (uchar)this.GetProperty(PEND_REQ_PROP_ID);                     }
   int                  Retcode(void)                                      const { return (int)this.GetProperty(PEND_REQ_PROP_RETCODE);                  }
   ulong                Order(void)                                        const { return this.GetProperty(PEND_REQ_PROP_MQL_REQ_ORDER);                 }
   ulong                Position(void)                                     const { return this.GetProperty(PEND_REQ_PROP_MQL_REQ_POSITION);              }
   ENUM_TRADE_REQUEST_ACTIONS Action(void)                                 const { return (ENUM_TRADE_REQUEST_ACTIONS)this.GetProperty(PEND_REQ_PROP_MQL_REQ_ACTION);}

//--- Set (1) the price when creating a request, (2) request creation time,
//--- (3) current attempt time, (4) waiting time between requests,
//--- (5) current attempt index, (6) number of attempts, (7) ID,
//--- (8) order ticket, (9) position ticket
   void                 SetPriceCreate(const double price)                       { this.SetProperty(PEND_REQ_PROP_PRICE_CREATE,price);                   }
   void                 SetTimeCreate(const ulong time)                          { this.SetProperty(PEND_REQ_PROP_TIME_CREATE,time);                     }
   void                 SetTimeActivate(const ulong time)                        { this.SetProperty(PEND_REQ_PROP_TIME_ACTIVATE,time);                   }
   void                 SetWaitingMSC(const ulong miliseconds)                   { this.SetProperty(PEND_REQ_PROP_WAITING,miliseconds);                  }
   void                 SetCurrentAttempt(const uchar number)                    { this.SetProperty(PEND_REQ_PROP_CURENT,number);                        }
   void                 SetTotalAttempts(const uchar number)                     { this.SetProperty(PEND_REQ_PROP_TOTAL,number);                         }
   void                 SetID(const uchar id)                                    { this.SetProperty(PEND_REQ_PROP_ID,id);                                }
   void                 SetOrder(const ulong ticket)                             { this.SetProperty(PEND_REQ_PROP_MQL_REQ_ORDER,ticket);                 }
   void                 SetPosition(const ulong ticket)                          { this.SetProperty(PEND_REQ_PROP_MQL_REQ_POSITION,ticket);              }
   
//+------------------------------------------------------------------+
//| Descriptions of request object properties                        |
//+------------------------------------------------------------------+
//--- Get description of a request (1) integer, (2) real and (3) string property
   string               GetPropertyDescription(ENUM_PEND_REQ_PROP_INTEGER property);
   string               GetPropertyDescription(ENUM_PEND_REQ_PROP_DOUBLE property);
   string               GetPropertyDescription(ENUM_PEND_REQ_PROP_STRING property);

//--- Return the names of pending request object parameters
   string               StatusDescription(void)                const;
   string               TypeRequestDescription(void)           const;
   string               IDDescription(void)                    const;
   string               RetcodeDescription(void)               const;
   string               TimeCreateDescription(void)            const;
   string               TimeActivateDescription(void)          const;
   string               TimeWaitingDescription(void)           const;
   string               CurrentAttemptDescription(void)        const;

   string               TotalAttemptsDescription(void)         const;
   string               PriceCreateDescription(void)           const;
   
//--- Return the names of trading request structures parameters in the request object
   string               MqlReqActionDescription(void)          const;
   string               MqlReqMagicDescription(void)           const;
   string               MqlReqOrderDescription(void)           const;
   string               MqlReqSymbolDescription(void)          const;
   string               MqlReqVolumeDescription(void)          const;
   string               MqlReqPriceDescription(void)           const;
   string               MqlReqStopLimitDescription(void)       const;
   string               MqlReqStopLossDescription(void)        const;
   string               MqlReqTakeProfitDescription(void)      const;
   string               MqlReqDeviationDescription(void)       const;
   string               MqlReqTypeOrderDescription(void)       const;
   string               MqlReqTypeFillingDescription(void)     const;
   string               MqlReqTypeTimeDescription(void)        const;
   string               MqlReqExpirationDescription(void)      const;
   string               MqlReqCommentDescription(void)         const;
   string               MqlReqPositionDescription(void)        const;
   string               MqlReqPositionByDescription(void)      const;

//--- Display (1) description of request properties (full_prop=true - all properties, false - only supported ones),
//--- (2) short event message (implementation in the class descendants) in the journal
   void                 Print(const bool full_prop=false);
   virtual void         PrintShort(void){;}
  };
//+------------------------------------------------------------------+

我们已多次创建相同的对象，并对其结构进行了详细阐述。 我认为，于此没有必要再讨论对象结构原理。 就像所有其他类似对象，它有三个数组，用于存储整数型、实数型和字符串型属性。 此外，它还具有按指定属性常量访问这些属性的方法 —GetProperty()，以及见名知意的简化方法。 还有一些方法可以显示所有对象属性的说明。 一般来说，对于函数库对象一切都是标准化的。 您可以在第一篇文章中探索函数库对象的结构。

在类主体外部编写闭合的类构造函数：

//+------------------------------------------------------------------+
//| Constructor                                                      |
//+------------------------------------------------------------------+
CPendRequest::CPendRequest(const ENUM_PEND_REQ_STATUS status,
                           const uchar id,
                           const double price,
                           const ulong time,
                           const MqlTradeRequest &request,
                           const int retcode)
  {
   this.CopyRequest(request);
   this.m_is_hedge=#ifdef __MQL4__ true #else bool(::AccountInfoInteger(ACCOUNT_MARGIN_MODE)==ACCOUNT_MARGIN_MODE_RETAIL_HEDGING) #endif;
   this.m_digits=(int)::SymbolInfoInteger(this.GetProperty(PEND_REQ_PROP_MQL_REQ_SYMBOL),SYMBOL_DIGITS);
   int dg=(int)DigitsLots(this.GetProperty(PEND_REQ_PROP_MQL_REQ_SYMBOL));
   this.m_digits_lot=(dg==0 ? 1 : dg);
   this.SetProperty(PEND_REQ_PROP_STATUS,status);
   this.SetProperty(PEND_REQ_PROP_ID,id);
   this.SetProperty(PEND_REQ_PROP_RETCODE,retcode);
   this.SetProperty(PEND_REQ_PROP_TYPE,this.GetProperty(PEND_REQ_PROP_RETCODE)>0 ? PEND_REQ_TYPE_ERROR : PEND_REQ_TYPE_REQUEST);
   this.SetProperty(PEND_REQ_PROP_TIME_CREATE,time);
   this.SetProperty(PEND_REQ_PROP_PRICE_CREATE,price);
  }
//+------------------------------------------------------------------+

首先，利用我们下面要研究的 CopyRequest() 方法将交易请求结构数据复制到整数型、实数型和字符串型属性的数组。
接下来，设置对冲帐户标志，设置品种报价和手数值中的小数位数（这是在日志中正确显示信息所必需的）。 如果手数值中的小数位数为零，则出于便利起见，仅显示一个小数位：显示 “1.0” 替代 “1”。
接下来，为相应的对象属性创建请求对象时，简单地将所传递的某些属性值赋值给类构造函数即可。
因此，我们在创建延后请求对象后立即填充其所有属性。

按指定的属性（模式）比较两个延后请求对象的方法：

//+------------------------------------------------------------------+
//| Compare CPendRequest objects by a specified property             |
//+------------------------------------------------------------------+
int CPendRequest::Compare(const CObject *node,const int mode=0) const
  {
   const CPendRequest *compared_obj=node;
//--- compare integer properties of two events
   if(mode<PEND_REQ_PROP_INTEGER_TOTAL)
     {
      long value_compared=compared_obj.GetProperty((ENUM_PEND_REQ_PROP_INTEGER)mode);
      long value_current=this.GetProperty((ENUM_PEND_REQ_PROP_INTEGER)mode);
      return(value_current>value_compared ? 1 : value_current<value_compared ? -1 : 0);
     }
//--- compare integer properties of two objects
   if(mode<PEND_REQ_PROP_DOUBLE_TOTAL+PEND_REQ_PROP_INTEGER_TOTAL)
     {
      double value_compared=compared_obj.GetProperty((ENUM_PEND_REQ_PROP_DOUBLE)mode);
      double value_current=this.GetProperty((ENUM_PEND_REQ_PROP_DOUBLE)mode);
      return(value_current>value_compared ? 1 : value_current<value_compared ? -1 : 0);
     }
//--- compare string properties of two objects
   else if(mode<PEND_REQ_PROP_DOUBLE_TOTAL+PEND_REQ_PROP_INTEGER_TOTAL+PEND_REQ_PROP_STRING_TOTAL)
     {
      string value_compared=compared_obj.GetProperty((ENUM_PEND_REQ_PROP_STRING)mode);
      string value_current=this.GetProperty((ENUM_PEND_REQ_PROP_STRING)mode);
      return(value_current>value_compared ? 1 : value_current<value_compared ? -1 : 0);
     }
   return 0;
  }
//+------------------------------------------------------------------+

按其所有属性完整比较两个延后请求对象的方法：

//+------------------------------------------------------------------+
//| Compare CPendRequest objects by all properties                   |
//+------------------------------------------------------------------+
bool CPendRequest::IsEqual(CPendRequest *compared_obj)
  {
   int beg=0, end=PEND_REQ_PROP_INTEGER_TOTAL;
   for(int i=beg; i<end; i++)
     {
      ENUM_PEND_REQ_PROP_INTEGER prop=(ENUM_PEND_REQ_PROP_INTEGER)i;
      if(this.GetProperty(prop)!=compared_obj.GetProperty(prop)) return false; 
     }
   beg=end; end+=PEND_REQ_PROP_DOUBLE_TOTAL;
   for(int i=beg; i<end; i++)
     {
      ENUM_PEND_REQ_PROP_DOUBLE prop=(ENUM_PEND_REQ_PROP_DOUBLE)i;
      if(this.GetProperty(prop)!=compared_obj.GetProperty(prop)) return false; 
     }
   beg=end; end+=PEND_REQ_PROP_STRING_TOTAL;
   for(int i=beg; i<end; i++)
     {
      ENUM_PEND_REQ_PROP_STRING prop=(ENUM_PEND_REQ_PROP_STRING)i;
      if(this.GetProperty(prop)!=compared_obj.GetProperty(prop)) return false; 
     }
//--- All properties are equal
   return true;
  }
//+------------------------------------------------------------------+

在先前创建函数库对象时，我们也层研究过此种方法。
您可能还记得，请求对象的 Compare() 方法按指定属性进行比较，该方法按当前 CPendRequest 类对象的指定属性与传递给该方法的同类对象进行比较 。 如果当前对象的值超过比较对象的值，则该方法返回 1，如果其小于比较对象的值，则返回 -1，否则返回 0。 运用指向对象的指针列表是必要的 — 配合其 Search() 方法，该方法利用标准库基准对象的 Compare() 虚方法进行快速比较。 由于该方法是虚拟的，因此应在 CObject 类的后代中重新定义该方法。 这正是我在这里所做的。
IsEqual() 方法逐一比较两个对象的每个属性，并在检测到不相等后立即返回 false — 对象不相等。 依据两个比较对象的所有属性完成三个循环之后，返回 true — 所有对象属性相等。

将交易请求结构复制到延后请求对象属性数组的方法：

//+------------------------------------------------------------------+
//| Copy trading request data                                        |
//+------------------------------------------------------------------+
void CPendRequest::CopyRequest(const MqlTradeRequest &request)
  {
//--- Copy a passed structure to an object structure
   this.m_request=request;

//--- Integer properties of a trading request structure
   this.SetProperty(PEND_REQ_PROP_MQL_REQ_ACTION,request.action);             // Type of a performed action in the request structure
   this.SetProperty(PEND_REQ_PROP_MQL_REQ_TYPE,request.type);                 // Order type in the request structure
   this.SetProperty(PEND_REQ_PROP_MQL_REQ_MAGIC,request.magic);               // EA stamp (magic number ID) in the request structure
   this.SetProperty(PEND_REQ_PROP_MQL_REQ_ORDER,request.order);               // Order ticket in the request structure
   this.SetProperty(PEND_REQ_PROP_MQL_REQ_POSITION,request.position);         // Position ticket in the request structure
   this.SetProperty(PEND_REQ_PROP_MQL_REQ_POSITION_BY,request.position_by);   // Opposite position ticket in the request structure
   this.SetProperty(PEND_REQ_PROP_MQL_REQ_DEVIATION,request.deviation);       // Maximum acceptable deviation from a requested price in the request structure
   this.SetProperty(PEND_REQ_PROP_MQL_REQ_EXPIRATION,request.expiration);     // Order expiration time (for ORDER_TIME_SPECIFIED type orders) in the request structure
   this.SetProperty(PEND_REQ_PROP_MQL_REQ_TYPE_FILLING,request.type_filling); // Order filling type in the request structure
   this.SetProperty(PEND_REQ_PROP_MQL_REQ_TYPE_TIME,request.type_time);       // Order lifetime type in the request structure
//--- Real properties of a trading request structure
   this.SetProperty(PEND_REQ_PROP_MQL_REQ_VOLUME,request.volume);             // Requested volume of a deal in lots in the request structure
   this.SetProperty(PEND_REQ_PROP_MQL_REQ_PRICE,request.price);               // Price in the request structure
   this.SetProperty(PEND_REQ_PROP_MQL_REQ_STOPLIMIT,request.stoplimit);       // StopLimit level in the request structure
   this.SetProperty(PEND_REQ_PROP_MQL_REQ_SL,request.sl);                     // Stop Loss level in the request structure
   this.SetProperty(PEND_REQ_PROP_MQL_REQ_TP,request.tp);                     // Take Profit level in the request structure
//--- String properties of a trading request structure
   this.SetProperty(PEND_REQ_PROP_MQL_REQ_SYMBOL,request.symbol);             // Trading instrument name in the request structure
   this.SetProperty(PEND_REQ_PROP_MQL_REQ_COMMENT,request.comment);           // Order comment in the request structure
  }
//+------------------------------------------------------------------+

此处，我们首先将传递给方法的交易请求结构的所有字段值复制到相同的请求对象结构。 然后，利用设置属性的 SetProperty() 方法为对象属性的所有结构字段设置数值。

返回延后请求对象的整数型、实数型和字符串型属性说明的方法：

//+------------------------------------------------------------------+
//| Return the description of the request integer property           |
//+------------------------------------------------------------------+
string CPendRequest::GetPropertyDescription(ENUM_PEND_REQ_PROP_INTEGER property)
  {
   return
     (
      property==PEND_REQ_PROP_STATUS               ?  this.StatusDescription()            :
      property==PEND_REQ_PROP_TYPE                 ?  this.TypeRequestDescription()       :
      property==PEND_REQ_PROP_ID                   ?  this.IDDescription()                :
      property==PEND_REQ_PROP_RETCODE              ?  this.RetcodeDescription()           :
      property==PEND_REQ_PROP_TIME_CREATE          ?  this.TimeCreateDescription()        :
      property==PEND_REQ_PROP_TIME_ACTIVATE        ?  this.TimeActivateDescription()      :
      property==PEND_REQ_PROP_WAITING              ?  this.TimeWaitingDescription()       :
      property==PEND_REQ_PROP_CURENT               ?  this.CurrentAttemptDescription()    :

      property==PEND_REQ_PROP_TOTAL                ?  this.TotalAttemptsDescription()     :
      //--- MqlTradeRequest
      property==PEND_REQ_PROP_MQL_REQ_ACTION       ?  this.MqlReqActionDescription()      :
      property==PEND_REQ_PROP_MQL_REQ_TYPE         ?  this.MqlReqTypeOrderDescription()   :
      property==PEND_REQ_PROP_MQL_REQ_MAGIC        ?  this.MqlReqMagicDescription()       :
      property==PEND_REQ_PROP_MQL_REQ_ORDER        ?  this.MqlReqOrderDescription()       :
      property==PEND_REQ_PROP_MQL_REQ_POSITION     ?  this.MqlReqPositionDescription()    :
      property==PEND_REQ_PROP_MQL_REQ_POSITION_BY  ?  this.MqlReqPositionByDescription()  :
      property==PEND_REQ_PROP_MQL_REQ_DEVIATION    ?  this.MqlReqDeviationDescription()   :
      property==PEND_REQ_PROP_MQL_REQ_EXPIRATION   ?  this.MqlReqExpirationDescription()  :
      property==PEND_REQ_PROP_MQL_REQ_TYPE_FILLING ?  this.MqlReqTypeFillingDescription() :
      property==PEND_REQ_PROP_MQL_REQ_TYPE_TIME    ?  this.MqlReqTypeTimeDescription()    :
      ::EnumToString(property)
     );
  }
//+------------------------------------------------------------------+
//| Return the description of the request real property              |
//+------------------------------------------------------------------+
string CPendRequest::GetPropertyDescription(ENUM_PEND_REQ_PROP_DOUBLE property)
  {
   return
     (
      property==PEND_REQ_PROP_PRICE_CREATE      ?  this.PriceCreateDescription()          :
      //--- MqlTradeRequest
      property==PEND_REQ_PROP_MQL_REQ_VOLUME    ?  this.MqlReqVolumeDescription()         :
      property==PEND_REQ_PROP_MQL_REQ_PRICE     ?  this.MqlReqPriceDescription()          :
      property==PEND_REQ_PROP_MQL_REQ_STOPLIMIT ?  this.MqlReqStopLimitDescription()      :
      property==PEND_REQ_PROP_MQL_REQ_SL        ?  this.MqlReqStopLossDescription()       :
      property==PEND_REQ_PROP_MQL_REQ_TP        ?  this.MqlReqTakeProfitDescription()     :
      ::EnumToString(property)
     );
  }
//+------------------------------------------------------------------+
//| Return the description of the request string property            |
//+------------------------------------------------------------------+
string CPendRequest::GetPropertyDescription(ENUM_PEND_REQ_PROP_STRING property)
  {
   return
     (
      property==PEND_REQ_PROP_MQL_REQ_SYMBOL    ?  this.MqlReqSymbolDescription()         :
      property==PEND_REQ_PROP_MQL_REQ_COMMENT   ?  this.MqlReqCommentDescription()        :
      ::EnumToString(property)
     );
  }
//+------------------------------------------------------------------+

该方法接收属性和依据该属性值返回的说明字符串：

//+------------------------------------------------------------------+
//| Return the pending request status name                           |
//+------------------------------------------------------------------+
string CPendRequest::StatusDescription(void) const
  {
   int code_descr=
     (
      this.GetProperty(PEND_REQ_PROP_STATUS)==PEND_REQ_STATUS_OPEN   ?  MSG_LIB_TEXT_PEND_REQUEST_STATUS_OPEN     :
      this.GetProperty(PEND_REQ_PROP_STATUS)==PEND_REQ_STATUS_CLOSE  ?  MSG_LIB_TEXT_PEND_REQUEST_STATUS_CLOSE    :
      this.GetProperty(PEND_REQ_PROP_STATUS)==PEND_REQ_STATUS_SLTP   ?  MSG_LIB_TEXT_PEND_REQUEST_STATUS_SLTP     :
      this.GetProperty(PEND_REQ_PROP_STATUS)==PEND_REQ_STATUS_PLACE  ?  MSG_LIB_TEXT_PEND_REQUEST_STATUS_PLACE    :
      this.GetProperty(PEND_REQ_PROP_STATUS)==PEND_REQ_STATUS_REMOVE ?  MSG_LIB_TEXT_PEND_REQUEST_STATUS_REMOVE   :
      this.GetProperty(PEND_REQ_PROP_STATUS)==PEND_REQ_STATUS_MODIFY ?  MSG_LIB_TEXT_PEND_REQUEST_STATUS_MODIFY   :
      MSG_EVN_STATUS_UNKNOWN
     );
   return CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_STATUS)+": "+CMessage::Text(code_descr);
  }
//+------------------------------------------------------------------+
//| Return the pending request type name                             |
//+------------------------------------------------------------------+
string CPendRequest::TypeRequestDescription(void) const
  {
   int code_descr=
     (
      this.GetProperty(PEND_REQ_PROP_TYPE)==PEND_REQ_TYPE_ERROR   ?  MSG_LIB_TEXT_PEND_REQUEST_BY_ERROR     :
      this.GetProperty(PEND_REQ_PROP_TYPE)==PEND_REQ_TYPE_REQUEST ?  MSG_LIB_TEXT_PEND_REQUEST_BY_REQUEST   :
      MSG_SYM_MODE_UNKNOWN
     );
   return CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_TYPE)+": "+CMessage::Text(code_descr);
  }
//+------------------------------------------------------------------+
//| Return the pending request ID description                        |
//+------------------------------------------------------------------+
string CPendRequest::IDDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_ID)+": #"+(string)this.GetProperty(PEND_REQ_PROP_ID);
  }
//+------------------------------------------------------------------+
//| Return the description of an error code a request is based on    |
//+------------------------------------------------------------------+
string CPendRequest::RetcodeDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_RETCODE)+": "+
          CMessage::Text((int)this.GetProperty(PEND_REQ_PROP_RETCODE))+
          " ("+(string)this.GetProperty(PEND_REQ_PROP_RETCODE)+")";
  }
//+------------------------------------------------------------------+
//| Return the description of a pending request creation time        |
//+------------------------------------------------------------------+
string CPendRequest::TimeCreateDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_TIME_CREATE)+": "+::TimeMSCtoString(this.GetProperty(PEND_REQ_PROP_TIME_CREATE));
  }
//+------------------------------------------------------------------+
//| Return the description of a pending request activation time      |
//+------------------------------------------------------------------+
string CPendRequest::TimeActivateDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_TIME_ACTIVATE)+": "+::TimeMSCtoString(this.GetProperty(PEND_REQ_PROP_TIME_ACTIVATE));
  }
//+----------------------------------------------------------------------+
//| Return the description of a time spent waiting for a pending request |
//+----------------------------------------------------------------------+
string CPendRequest::TimeWaitingDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_WAITING)+": "+
          (string)this.GetProperty(PEND_REQ_PROP_WAITING)+
          " ("+::TimeToString(this.GetProperty(PEND_REQ_PROP_WAITING)/1000,TIME_MINUTES|TIME_SECONDS)+")";
  }
//+------------------------------------------------------------------+
//| Return the description of the current pending request attempt    |
//+------------------------------------------------------------------+
string CPendRequest::CurrentAttemptDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_CURRENT_ATTEMPT)+": "+(string)this.GetProperty(PEND_REQ_PROP_CURENT);
  }
//+------------------------------------------------------------------+
//| Return the description of a number of pending request attempts   |
//+------------------------------------------------------------------+
string CPendRequest::TotalAttemptsDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_TOTAL_ATTEMPTS)+": "+(string)this.GetProperty(PEND_REQ_PROP_TOTAL);
  }
//+------------------------------------------------------------------+
//| Return the description of a price when creating a request        |
//+------------------------------------------------------------------+
string CPendRequest::PriceCreateDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_PRICE_CREATE)+": "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_PRICE_CREATE),this.m_digits);
  }
//+------------------------------------------------------------------+
//| Return the executed action type description                      |
//+------------------------------------------------------------------+
string CPendRequest::MqlReqActionDescription(void) const
  {
   int code_descr=
     (
      this.GetProperty(PEND_REQ_PROP_MQL_REQ_ACTION)==TRADE_ACTION_DEAL       ?  MSG_LIB_TEXT_REQUEST_ACTION_DEAL       :
      this.GetProperty(PEND_REQ_PROP_MQL_REQ_ACTION)==TRADE_ACTION_PENDING    ?  MSG_LIB_TEXT_REQUEST_ACTION_PENDING    :
      this.GetProperty(PEND_REQ_PROP_MQL_REQ_ACTION)==TRADE_ACTION_SLTP       ?  MSG_LIB_TEXT_REQUEST_ACTION_SLTP       :
      this.GetProperty(PEND_REQ_PROP_MQL_REQ_ACTION)==TRADE_ACTION_MODIFY     ?  MSG_LIB_TEXT_REQUEST_ACTION_MODIFY     :
      this.GetProperty(PEND_REQ_PROP_MQL_REQ_ACTION)==TRADE_ACTION_REMOVE     ?  MSG_LIB_TEXT_REQUEST_ACTION_REMOVE     :
      this.GetProperty(PEND_REQ_PROP_MQL_REQ_ACTION)==TRADE_ACTION_CLOSE_BY   ?  MSG_LIB_TEXT_REQUEST_ACTION_CLOSE_BY   :
      MSG_LIB_TEXT_REQUEST_ACTION_UNCNOWN
     );
   return CMessage::Text(MSG_LIB_TEXT_REQUEST_ACTION)+": "+CMessage::Text(code_descr);
  }
//+------------------------------------------------------------------+
//| Return the magic number value description                        |
//+------------------------------------------------------------------+
string CPendRequest::MqlReqMagicDescription(void) const
  {
   return CMessage::Text(MSG_ORD_MAGIC)+": "+(string)this.GetProperty(PEND_REQ_PROP_MQL_REQ_MAGIC)+
          (this.GetMagicID()!=this.GetProperty(PEND_REQ_PROP_MQL_REQ_MAGIC) ? " ("+(string)this.GetMagicID()+")" : "");
  }
//+------------------------------------------------------------------+
//| Return the order ticket value description                        |
//+------------------------------------------------------------------+
string CPendRequest::MqlReqOrderDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_REQUEST_ORDER)+": "+
          (this.GetProperty(PEND_REQ_PROP_MQL_REQ_ORDER)>0 ? 
           "#"+(string)this.GetProperty(PEND_REQ_PROP_MQL_REQ_ORDER) : 
           CMessage::Text(MSG_LIB_PROP_NOT_SET));
  }
//+------------------------------------------------------------------+
//| Return the request position ticket description                   |
//+------------------------------------------------------------------+
string CPendRequest::MqlReqPositionDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_REQUEST_POSITION)+": "+
          (this.GetProperty(PEND_REQ_PROP_MQL_REQ_POSITION)>0 ? 
           (string)this.GetProperty(PEND_REQ_PROP_MQL_REQ_POSITION) : 
           CMessage::Text(MSG_LIB_PROP_NOT_SET));
  }
//+------------------------------------------------------------------+
//| Return the request opposite position ticket description          |
//+------------------------------------------------------------------+
string CPendRequest::MqlReqPositionByDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_REQUEST_POSITION_BY)+": "+
          (this.GetProperty(PEND_REQ_PROP_MQL_REQ_POSITION_BY)>0 ? 
           (string)this.GetProperty(PEND_REQ_PROP_MQL_REQ_POSITION_BY) : 
           CMessage::Text(MSG_LIB_PROP_NOT_SET));
  }
//+------------------------------------------------------------------+
//| Return the request deviation size description                    |
//+------------------------------------------------------------------+
string CPendRequest::MqlReqDeviationDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_REQUEST_DEVIATION)+": "+(string)this.GetProperty(PEND_REQ_PROP_MQL_REQ_DEVIATION);
  }
//+------------------------------------------------------------------+
//| Return the request order type description                        |
//+------------------------------------------------------------------+
string CPendRequest::MqlReqTypeOrderDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_REQUEST_TYPE)+": "+OrderTypeDescription((ENUM_ORDER_TYPE)this.GetProperty(PEND_REQ_PROP_MQL_REQ_TYPE));
  }
//+------------------------------------------------------------------+
//| Return the request order filling mode description                |
//+------------------------------------------------------------------+
string CPendRequest::MqlReqTypeFillingDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_REQUEST_TYPE_FILLING)+": "+OrderTypeFillingDescription((ENUM_ORDER_TYPE_FILLING)this.GetProperty(PEND_REQ_PROP_MQL_REQ_TYPE_FILLING));
  }
//+------------------------------------------------------------------+
//| Return the request order lifetime type description               |
//+------------------------------------------------------------------+
string CPendRequest::MqlReqTypeTimeDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_REQUEST_TYPE_TIME)+": "+OrderTypeTimeDescription((ENUM_ORDER_TYPE_TIME)this.GetProperty(PEND_REQ_PROP_MQL_REQ_TYPE_TIME));
  }
//+------------------------------------------------------------------+
//| Return the request order expiration time description             |
//+------------------------------------------------------------------+
string CPendRequest::MqlReqExpirationDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_REQUEST_EXPIRATION)+": "+
          (this.GetProperty(PEND_REQ_PROP_MQL_REQ_EXPIRATION)>0 ? 
           ::TimeToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_EXPIRATION)) : 
           CMessage::Text(MSG_LIB_PROP_NOT_SET));
  }
//+------------------------------------------------------------------+
//| Return the request volume description                            |
//+------------------------------------------------------------------+
string CPendRequest::MqlReqVolumeDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_REQUEST_VOLUME)+": "+
          (this.GetProperty(PEND_REQ_PROP_MQL_REQ_VOLUME)>0 ? 
           ::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_VOLUME),this.m_digits_lot) : 
           CMessage::Text(MSG_LIB_PROP_NOT_SET));
  }
//+------------------------------------------------------------------+
//| Return the request price value description                       |
//+------------------------------------------------------------------+
string CPendRequest::MqlReqPriceDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_REQUEST_PRICE)+": "+
          (this.GetProperty(PEND_REQ_PROP_MQL_REQ_PRICE)>0 ? 
           ::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_PRICE),this.m_digits) : 
           CMessage::Text(MSG_LIB_PROP_NOT_SET));
  }
//+------------------------------------------------------------------+
//| Return the request StopLimit order price description             |
//+------------------------------------------------------------------+
string CPendRequest::MqlReqStopLimitDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_REQUEST_STOPLIMIT)+": "+
          (this.GetProperty(PEND_REQ_PROP_MQL_REQ_STOPLIMIT)>0 ? 
           ::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_STOPLIMIT),this.m_digits) : 
           CMessage::Text(MSG_LIB_PROP_NOT_SET));
  }
//+------------------------------------------------------------------+
//| Return the request StopLoss order price description              |
//+------------------------------------------------------------------+
string CPendRequest::MqlReqStopLossDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_REQUEST_SL)+": "+
          (this.GetProperty(PEND_REQ_PROP_MQL_REQ_SL)>0 ? 
           ::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_SL),this.m_digits) : 
           CMessage::Text(MSG_LIB_PROP_NOT_SET));
  }
//+------------------------------------------------------------------+
//| Return the request TakeProfit order price description            |
//+------------------------------------------------------------------+
string CPendRequest::MqlReqTakeProfitDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_REQUEST_TP)+": "+
          (this.GetProperty(PEND_REQ_PROP_MQL_REQ_TP)>0 ? 
           ::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_TP),this.m_digits) : 
           CMessage::Text(MSG_LIB_PROP_NOT_SET));
  }
//+------------------------------------------------------------------+
//| Return the description of a trading instrument name in a request |
//+------------------------------------------------------------------+
string CPendRequest::MqlReqSymbolDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_REQUEST_SYMBOL)+": "+this.GetProperty(PEND_REQ_PROP_MQL_REQ_SYMBOL);
  }
//+------------------------------------------------------------------+
//| Return the request order comment description                     |
//+------------------------------------------------------------------+
string CPendRequest::MqlReqCommentDescription(void) const
  {
   return CMessage::Text(MSG_LIB_TEXT_REQUEST_COMMENT)+": "+
          (this.GetProperty(PEND_REQ_PROP_MQL_REQ_COMMENT)!="" && this.GetProperty(PEND_REQ_PROP_MQL_REQ_COMMENT)!=NULL ? 
           "/""+this.GetProperty(PEND_REQ_PROP_MQL_REQ_COMMENT)+"/"" : 
           CMessage::Text(MSG_LIB_PROP_NOT_SET));
  }
//+------------------------------------------------------------------+

在方法中检查所传递的属性值，为其创建文本描述，并返回生成的文本。

Print() 方法在日志中显示所有对象属性：

//+------------------------------------------------------------------+
//| Display the pending request properties in the journal            |
//+------------------------------------------------------------------+
void CPendRequest::Print(const bool full_prop=false)
  {
   int header_code=
     (
      this.GetProperty(PEND_REQ_PROP_STATUS)==PEND_REQ_STATUS_OPEN   ? MSG_LIB_TEXT_PEND_REQUEST_STATUS_OPEN   :
      this.GetProperty(PEND_REQ_PROP_STATUS)==PEND_REQ_STATUS_CLOSE  ? MSG_LIB_TEXT_PEND_REQUEST_STATUS_CLOSE  :
      this.GetProperty(PEND_REQ_PROP_STATUS)==PEND_REQ_STATUS_SLTP   ? MSG_LIB_TEXT_PEND_REQUEST_STATUS_SLTP   :
      this.GetProperty(PEND_REQ_PROP_STATUS)==PEND_REQ_STATUS_PLACE  ? MSG_LIB_TEXT_PEND_REQUEST_STATUS_PLACE  :
      this.GetProperty(PEND_REQ_PROP_STATUS)==PEND_REQ_STATUS_REMOVE ? MSG_LIB_TEXT_PEND_REQUEST_STATUS_REMOVE :
      this.GetProperty(PEND_REQ_PROP_STATUS)==PEND_REQ_STATUS_MODIFY ? MSG_LIB_TEXT_PEND_REQUEST_STATUS_MODIFY :
      WRONG_VALUE
     );
   ::Print("============= /"",CMessage::Text(header_code),"/" =============");
   int beg=0, end=PEND_REQ_PROP_INTEGER_TOTAL;
   for(int i=beg; i<end; i++)
     {
      ENUM_PEND_REQ_PROP_INTEGER prop=(ENUM_PEND_REQ_PROP_INTEGER)i;
      if(!full_prop && !this.SupportProperty(prop)) continue;
      ::Print(this.GetPropertyDescription(prop));
     }
   ::Print("------");
   beg=end; end+=PEND_REQ_PROP_DOUBLE_TOTAL;
   for(int i=beg; i<end; i++)
     {
      ENUM_PEND_REQ_PROP_DOUBLE prop=(ENUM_PEND_REQ_PROP_DOUBLE)i;
      if(!full_prop && !this.SupportProperty(prop)) continue;
      ::Print(this.GetPropertyDescription(prop));
     }
   ::Print("------");
   beg=end; end+=PEND_REQ_PROP_STRING_TOTAL;
   for(int i=beg; i<end; i++)
     {
      ENUM_PEND_REQ_PROP_STRING prop=(ENUM_PEND_REQ_PROP_STRING)i;
      if(!full_prop && !this.SupportProperty(prop)) continue;
      ::Print(this.GetPropertyDescription(prop));
     }
   ::Print("================== ",CMessage::Text(MSG_LIB_PARAMS_LIST_END),": /"",CMessage::Text(header_code),"/" ==================/n");
  }
//+------------------------------------------------------------------+

我们已为所有以前的函数库对象创建了此种方法，并自函数库论述的最开始就对其结构进行了分析，故此在这里我仅提供以下简要陈述：
在三重循环中移动三个对象属性数组，得到每个连续的对象属性，并依据该对象属性受支持的标志在日志中显示其描述。

PrintShort() 方法显示请求对象说明的摘要，且其为虚方法。 它在基准对象中不执行任何操作，而应在后代对象中重新定义，如此令每个后代在日志中只能显示其自己的属性。

我们已经创建了抽象延后请求的基准对象。
为了阐明应该生成什么请求，我们需要基于抽象请求对象创建六个后代对象。 在处理需要等待的错误时，在交易类的交易方法中会创建它们。 此外，在利用延后交易请求创建交易逻辑时，它们将被创建为独立的交易请求。

延后请求基准对象的衍生对象

交易类的每种交易方法都拥有创建延后请求的功能。 我们将基于交易方法所执行的操作来创建相应的延后请求。 但目前，我们只有一个基准抽象延后请求。 为了根据所执行操作的类型生成各种交易请求，我们需要创建六个后代，其中每个后代类仅将其自身的交易操作发送到服务器。 我已经在上面提供了此类对象的清单：

• 开仓
• 修改持仓的止价单
• 平仓
• 下挂单
• 修改挂单的属性
• 删除之前下达的挂单

您可能还记得，基准抽象请求的受保护构造函数所含有的参数可指示所生成的请求状态：

//--- Protected parametric constructor
                     CPendRequest(const ENUM_PEND_REQ_STATUS status,
                                  const uchar id,
                                  const double price,
                                  const ulong time,
                                  const MqlTradeRequest &request,
                                  const int retcode);

当创建一个新的延后请求时，我们将显示此状态（从所继承对象的构造函数传递到基准对象）。 这可令我们按照所执行操作设置将要生成的请求类型。 我们曾在第二篇文章的创建历史订单和成交对象中分析了这种行为。 所以，我们不会在这一点上停留，而是按照所执行交易操作的类型来研究所有六个延后请求对象。
基准交易请求后代对象的所有类都在基准对象所在的文件夹中创建：
/MQL5/Include/DoEasy/Objects/ PendRequest/

开仓的延后请求对象类 （PendReqOpen.mqh 类文件）：

//+------------------------------------------------------------------+
//|                                                  PendReqOpen.mqh |
//|                        Copyright 2019, MetaQuotes Software Corp. |
//|                             https://mql5.com/en/users/artmedia70 |
//+------------------------------------------------------------------+
#property copyright "Copyright 2019, MetaQuotes Software Corp."
#property link      "https://mql5.com/en/users/artmedia70"
#property version   "1.00"
//+------------------------------------------------------------------+
//| Include files                                                    |
//+------------------------------------------------------------------+
#include "PendRequest.mqh"
//+------------------------------------------------------------------+
//| Pending request for opening a position                           |
//+------------------------------------------------------------------+
class CPendReqOpen : public CPendRequest
  {
public:
//--- Constructor
                     CPendReqOpen(const uchar id,
                                  const double price,
                                  const ulong time,
                                  const MqlTradeRequest &request,
                                  const int retcode) : CPendRequest(PEND_REQ_STATUS_OPEN,id,price,time,request,retcode) {}
                                  
//--- Supported deal properties (1) real, (2) integer
   virtual bool      SupportProperty(ENUM_PEND_REQ_PROP_INTEGER property);
   virtual bool      SupportProperty(ENUM_PEND_REQ_PROP_DOUBLE property);
   virtual bool      SupportProperty(ENUM_PEND_REQ_PROP_STRING property);
//--- Display a brief message with request data in the journal
   virtual void      PrintShort(void);
  };
//+------------------------------------------------------------------+
//| Return 'true' if an order supports a passed                      |
//| integer property, otherwise return 'false'                       |
//+------------------------------------------------------------------+
bool CPendReqOpen::SupportProperty(ENUM_PEND_REQ_PROP_INTEGER property)
  {
   if(property==PEND_REQ_PROP_MQL_REQ_ORDER        ||
      property==PEND_REQ_PROP_MQL_REQ_POSITION     ||
      property==PEND_REQ_PROP_MQL_REQ_POSITION_BY  ||
      property==PEND_REQ_PROP_MQL_REQ_EXPIRATION   ||
      property==PEND_REQ_PROP_MQL_REQ_TYPE_TIME
     ) return false;
   return true;
  }
//+------------------------------------------------------------------+
//| Return 'true' if an order supports a passed                      |
//| real property, otherwise return 'false'                          |
//+------------------------------------------------------------------+
bool CPendReqOpen::SupportProperty(ENUM_PEND_REQ_PROP_DOUBLE property)
  {
   return(property==PEND_REQ_PROP_MQL_REQ_STOPLIMIT ? false : true);
  }
//+------------------------------------------------------------------+
//| Return 'true' if an order supports a passed                      |
//| string property, otherwise return 'false'                        |
//+------------------------------------------------------------------+
bool CPendReqOpen::SupportProperty(ENUM_PEND_REQ_PROP_STRING property)
  {
   return true;
  }
//+------------------------------------------------------------------+
//| Display a brief message with request data in the journal         |
//+------------------------------------------------------------------+
void CPendReqOpen::PrintShort(void)
  {
   string params=this.GetProperty(PEND_REQ_PROP_MQL_REQ_SYMBOL)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_VOLUME),this.m_digits_lot)+" "+
                 OrderTypeDescription((ENUM_ORDER_TYPE)this.GetProperty(PEND_REQ_PROP_MQL_REQ_TYPE));
   string price=CMessage::Text(MSG_LIB_TEXT_REQUEST_PRICE)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_PRICE),this.m_digits);
   string sl=this.GetProperty(PEND_REQ_PROP_MQL_REQ_SL)>0 ? ", "+CMessage::Text(MSG_LIB_TEXT_REQUEST_SL)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_SL),this.m_digits) : "";
   string tp=this.GetProperty(PEND_REQ_PROP_MQL_REQ_TP)>0 ? ", "+CMessage::Text(MSG_LIB_TEXT_REQUEST_TP)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_TP),this.m_digits) : "";
   string time=this.IDDescription()+", "+CMessage::Text(MSG_LIB_TEXT_CREATED)+" "+TimeMSCtoString(this.GetProperty(PEND_REQ_PROP_TIME_CREATE));
   string attempts=CMessage::Text(MSG_LIB_TEXT_ATTEMPTS)+" "+(string)this.GetProperty(PEND_REQ_PROP_TOTAL);
   string wait=CMessage::Text(MSG_LIB_TEXT_WAIT)+" "+::TimeToString(this.GetProperty(PEND_REQ_PROP_WAITING)/1000,TIME_SECONDS);
   string end=CMessage::Text(MSG_LIB_TEXT_END)+" "+
              TimeMSCtoString(this.GetProperty(PEND_REQ_PROP_TIME_CREATE)+this.GetProperty(PEND_REQ_PROP_WAITING)*this.GetProperty(PEND_REQ_PROP_TOTAL));
   //---
   string message=CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_STATUS_OPEN)+": "+
   "/n- "+params+", "+price+sl+tp+
   "/n- "+time+", "+attempts+", "+wait+", "+end+"/n";
   ::Print(message);
  }
//+------------------------------------------------------------------+

该方法非常原始。 它的唯一功能是将所创建对象的状态（开仓）以及构造函数的所有输入在初始化清单里传递给基准对象的构造函数：

//--- Constructor
   CPendReqOpen(const uchar id,
                const double price,
                const ulong time,
                const MqlTradeRequest &request,
                const int retcode) : CPendRequest(PEND_REQ_STATUS_OPEN,id,price,time,request,retcode) {}

虚方法返回对象支持某些整数型、实数型和字符串型属性的标志：

//+------------------------------------------------------------------+
//| Return 'true' if an order supports a passed                      |
//| integer property, otherwise return 'false'                       |
//+------------------------------------------------------------------+
bool CPendReqOpen::SupportProperty(ENUM_PEND_REQ_PROP_INTEGER property)
  {
   if(property==PEND_REQ_PROP_MQL_REQ_ORDER        ||
      property==PEND_REQ_PROP_MQL_REQ_POSITION     ||
      property==PEND_REQ_PROP_MQL_REQ_POSITION_BY  ||
      property==PEND_REQ_PROP_MQL_REQ_EXPIRATION   ||
      property==PEND_REQ_PROP_MQL_REQ_TYPE_TIME
     ) return false;
   return true;
  }
//+------------------------------------------------------------------+
//| Return 'true' if an order supports a passed                      |
//| real property, otherwise return 'false'                          |
//+------------------------------------------------------------------+
bool CPendReqOpen::SupportProperty(ENUM_PEND_REQ_PROP_DOUBLE property)
  {
   return(property==PEND_REQ_PROP_MQL_REQ_STOPLIMIT ? false : true);
  }
//+------------------------------------------------------------------+
//| Return 'true' if an order supports a passed                      |
//| string property, otherwise return 'false'                        |
//+------------------------------------------------------------------+
bool CPendReqOpen::SupportProperty(ENUM_PEND_REQ_PROP_STRING property)
  {
   return true;
  }
//+------------------------------------------------------------------+

如果基准抽象延后请求的后代对象不支持任何属性，则该方法返回 “false”，否则返回 “true”。 我们曾在第二篇文章里研究生成历史订单和成交对象时考虑过这个问题。

创建和显示请求简要描述的虚方法：

//+------------------------------------------------------------------+
//| Display a brief message with request data in the journal         |
//+------------------------------------------------------------------+
void CPendReqOpen::PrintShort(void)
  {
   string params=this.GetProperty(PEND_REQ_PROP_MQL_REQ_SYMBOL)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_VOLUME),this.m_digits_lot)+" "+
                 OrderTypeDescription((ENUM_ORDER_TYPE)this.GetProperty(PEND_REQ_PROP_MQL_REQ_TYPE));
   string price=CMessage::Text(MSG_LIB_TEXT_REQUEST_PRICE)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_PRICE),this.m_digits);
   string sl=this.GetProperty(PEND_REQ_PROP_MQL_REQ_SL)>0 ? ", "+CMessage::Text(MSG_LIB_TEXT_REQUEST_SL)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_SL),this.m_digits) : "";
   string tp=this.GetProperty(PEND_REQ_PROP_MQL_REQ_TP)>0 ? ", "+CMessage::Text(MSG_LIB_TEXT_REQUEST_TP)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_TP),this.m_digits) : "";
   string time=this.IDDescription()+", "+CMessage::Text(MSG_LIB_TEXT_CREATED)+" "+TimeMSCtoString(this.GetProperty(PEND_REQ_PROP_TIME_CREATE));
   string attempts=CMessage::Text(MSG_LIB_TEXT_ATTEMPTS)+" "+(string)this.GetProperty(PEND_REQ_PROP_TOTAL);
   string wait=CMessage::Text(MSG_LIB_TEXT_WAIT)+" "+::TimeToString(this.GetProperty(PEND_REQ_PROP_WAITING)/1000,TIME_SECONDS);
   string end=CMessage::Text(MSG_LIB_TEXT_END)+" "+
              TimeMSCtoString(this.GetProperty(PEND_REQ_PROP_TIME_CREATE)+this.GetProperty(PEND_REQ_PROP_WAITING)*this.GetProperty(PEND_REQ_PROP_TOTAL));
   //---
   string message=CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_STATUS_OPEN)+": "+
   "/n- "+params+", "+price+sl+tp+
   "/n- "+time+", "+attempts+", "+wait+", "+end+"/n";
   ::Print(message);
  }
//+------------------------------------------------------------------+

在方法中会为对象用到的某些参数创建说明行。 编译的最终消息显示在日志中。 此为虚方法，需在抽象请求基准对象的每个后代对象中自行实现其方式。

修改持仓止价单的延后请求对象类 (PendReqSLTP.mqh 类文件):

//+------------------------------------------------------------------+
//|                                                  PendReqSLTP.mqh |
//|                        Copyright 2019, MetaQuotes Software Corp. |
//|                             https://mql5.com/en/users/artmedia70 |
//+------------------------------------------------------------------+
#property copyright "Copyright 2019, MetaQuotes Software Corp."
#property link      "https://mql5.com/en/users/artmedia70"
#property version   "1.00"
//+------------------------------------------------------------------+
//| Include files                                                    |
//+------------------------------------------------------------------+
#include "PendRequest.mqh"
//+------------------------------------------------------------------+
//| Pending request to modify position stop orders                   |
//+------------------------------------------------------------------+
class CPendReqSLTP : public CPendRequest
  {
public:
//--- Constructor
                     CPendReqSLTP(const uchar id,
                                  const double price,
                                  const ulong time,
                                  const MqlTradeRequest &request,
                                  const int retcode) : CPendRequest(PEND_REQ_STATUS_SLTP,id,price,time,request,retcode) {}
                                  
//--- Supported deal properties (1) real, (2) integer
   virtual bool      SupportProperty(ENUM_PEND_REQ_PROP_INTEGER property);
   virtual bool      SupportProperty(ENUM_PEND_REQ_PROP_DOUBLE property);
   virtual bool      SupportProperty(ENUM_PEND_REQ_PROP_STRING property);
//--- Display a brief message with request data in the journal
   virtual void      PrintShort(void);
  };
//+------------------------------------------------------------------+
//| Return 'true' if an order supports a passed                      |
//| integer property, otherwise return 'false'                       |
//+------------------------------------------------------------------+
bool CPendReqSLTP::SupportProperty(ENUM_PEND_REQ_PROP_INTEGER property)
  {
   if(property==PEND_REQ_PROP_MQL_REQ_POSITION_BY  ||
      property==PEND_REQ_PROP_MQL_REQ_ORDER        ||
      property==PEND_REQ_PROP_MQL_REQ_EXPIRATION   ||
      property==PEND_REQ_PROP_MQL_REQ_DEVIATION    ||
      property==PEND_REQ_PROP_MQL_REQ_TYPE_FILLING ||
      property==PEND_REQ_PROP_MQL_REQ_TYPE_TIME
     ) return false;
   return true;
  }
//+------------------------------------------------------------------+
//| Return 'true' if an order supports a passed                      |
//| real property, otherwise return 'false'                          |
//+------------------------------------------------------------------+
bool CPendReqSLTP::SupportProperty(ENUM_PEND_REQ_PROP_DOUBLE property)
  {
   if(property==PEND_REQ_PROP_PRICE_CREATE         ||
      property==PEND_REQ_PROP_MQL_REQ_SL           ||
      property==PEND_REQ_PROP_MQL_REQ_TP
     ) return true;
   return false;
  }
//+------------------------------------------------------------------+
//| Return 'true' if an order supports a passed                      |
//| string property, otherwise return 'false'                        |
//+------------------------------------------------------------------+
bool CPendReqSLTP::SupportProperty(ENUM_PEND_REQ_PROP_STRING property)
  {
   return true;
  }
//+------------------------------------------------------------------+
//| Display a brief message with request data in the journal         |
//+------------------------------------------------------------------+
void CPendReqSLTP::PrintShort(void)
  {
   string params=this.GetProperty(PEND_REQ_PROP_MQL_REQ_SYMBOL)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_VOLUME),this.m_digits_lot)+" "+
                 PositionTypeDescription((ENUM_POSITION_TYPE)this.GetProperty(PEND_REQ_PROP_MQL_REQ_TYPE))+" #"+(string)this.GetProperty(PEND_REQ_PROP_MQL_REQ_POSITION);
   string sl=this.GetProperty(PEND_REQ_PROP_MQL_REQ_SL)>0 ? ", "+CMessage::Text(MSG_LIB_TEXT_REQUEST_SL)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_SL),this.m_digits) : "";
   string tp=this.GetProperty(PEND_REQ_PROP_MQL_REQ_TP)>0 ? ", "+CMessage::Text(MSG_LIB_TEXT_REQUEST_TP)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_TP),this.m_digits) : "";
   string time=this.IDDescription()+", "+CMessage::Text(MSG_LIB_TEXT_CREATED)+" "+TimeMSCtoString(this.GetProperty(PEND_REQ_PROP_TIME_CREATE));
   string attempts=CMessage::Text(MSG_LIB_TEXT_ATTEMPTS)+" "+(string)this.GetProperty(PEND_REQ_PROP_TOTAL);
   string wait=CMessage::Text(MSG_LIB_TEXT_WAIT)+" "+::TimeToString(this.GetProperty(PEND_REQ_PROP_WAITING)/1000,TIME_SECONDS);
   string end=CMessage::Text(MSG_LIB_TEXT_END)+" "+
              TimeMSCtoString(this.GetProperty(PEND_REQ_PROP_TIME_CREATE)+this.GetProperty(PEND_REQ_PROP_WAITING)*this.GetProperty(PEND_REQ_PROP_TOTAL));
   //---
   string message=CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_STATUS_SLTP)+": "+
   "/n- "+params+sl+tp+
   "/n- "+time+", "+attempts+", "+wait+", "+end+"/n";
   ::Print(message);
  }
//+------------------------------------------------------------------+

平仓的延后请求对象类 (PendReqClose.mqh 类文件):

//+------------------------------------------------------------------+
//|                                                 PendReqClose.mqh |
//|                        Copyright 2019, MetaQuotes Software Corp. |
//|                             https://mql5.com/en/users/artmedia70 |
//+------------------------------------------------------------------+
#property copyright "Copyright 2019, MetaQuotes Software Corp."
#property link      "https://mql5.com/en/users/artmedia70"
#property version   "1.00"
//+------------------------------------------------------------------+
//| Include files                                                    |
//+------------------------------------------------------------------+
#include "PendRequest.mqh"
//+------------------------------------------------------------------+
//| Pending request to close a position                              |
//+------------------------------------------------------------------+
class CPendReqClose : public CPendRequest
  {
public:
//--- Constructor
                     CPendReqClose(const uchar id,
                                   const double price,
                                   const ulong time,
                                   const MqlTradeRequest &request,
                                   const int retcode) : CPendRequest(PEND_REQ_STATUS_CLOSE,id,price,time,request,retcode) {}
                                  
//--- Supported deal properties (1) real, (2) integer
   virtual bool      SupportProperty(ENUM_PEND_REQ_PROP_INTEGER property);
   virtual bool      SupportProperty(ENUM_PEND_REQ_PROP_DOUBLE property);
   virtual bool      SupportProperty(ENUM_PEND_REQ_PROP_STRING property);
//--- Display a brief message with request data in the journal
   virtual void      PrintShort(void);
  };
//+------------------------------------------------------------------+
//| Return 'true' if an order supports a passed                      |
//| integer property, otherwise return 'false'                       |
//+------------------------------------------------------------------+
bool CPendReqClose::SupportProperty(ENUM_PEND_REQ_PROP_INTEGER property)
  {
   if((
      property==PEND_REQ_PROP_MQL_REQ_POSITION_BY  && 
      this.GetProperty(property)==0)               ||
      property==PEND_REQ_PROP_MQL_REQ_ORDER        ||
      property==PEND_REQ_PROP_MQL_REQ_EXPIRATION   ||
      property==PEND_REQ_PROP_MQL_REQ_TYPE_TIME
     ) return false;
   return true;
  }
//+------------------------------------------------------------------+
//| Return 'true' if an order supports a passed                      |
//| real property, otherwise return 'false'                          |
//+------------------------------------------------------------------+
bool CPendReqClose::SupportProperty(ENUM_PEND_REQ_PROP_DOUBLE property)
  {
   if(property==PEND_REQ_PROP_MQL_REQ_STOPLIMIT    ||
      property==PEND_REQ_PROP_MQL_REQ_SL           ||
      property==PEND_REQ_PROP_MQL_REQ_TP
     ) return false;
   return true;
  }
//+------------------------------------------------------------------+
//| Return 'true' if an order supports a passed                      |
//| string property, otherwise return 'false'                        |
//+------------------------------------------------------------------+
bool CPendReqClose::SupportProperty(ENUM_PEND_REQ_PROP_STRING property)
  {
   return true;
  }
//+------------------------------------------------------------------+
//| Display a brief message with request data in the journal         |
//+------------------------------------------------------------------+
void CPendReqClose::PrintShort(void)
  {
   string params=this.GetProperty(PEND_REQ_PROP_MQL_REQ_SYMBOL)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_VOLUME),this.m_digits_lot)+" "+
                 PositionTypeDescription((ENUM_POSITION_TYPE)this.GetProperty(PEND_REQ_PROP_MQL_REQ_TYPE))+" #"+(string)this.GetProperty(PEND_REQ_PROP_MQL_REQ_POSITION);
   string pos_by=(this.GetProperty(PEND_REQ_PROP_MQL_REQ_POSITION_BY)>0 ? ", "+CMessage::Text(MSG_ORD_DEAL_OUT_BY)+" #"+(string)this.GetProperty(PEND_REQ_PROP_MQL_REQ_POSITION_BY) : "");
   string price=CMessage::Text(MSG_LIB_TEXT_REQUEST_PRICE)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_PRICE_CREATE),this.m_digits);
   string time=this.IDDescription()+", "+CMessage::Text(MSG_LIB_TEXT_CREATED)+" "+TimeMSCtoString(this.GetProperty(PEND_REQ_PROP_TIME_CREATE));
   string attempts=CMessage::Text(MSG_LIB_TEXT_ATTEMPTS)+" "+(string)this.GetProperty(PEND_REQ_PROP_TOTAL);
   string wait=CMessage::Text(MSG_LIB_TEXT_WAIT)+" "+::TimeToString(this.GetProperty(PEND_REQ_PROP_WAITING)/1000,TIME_SECONDS);
   string end=CMessage::Text(MSG_LIB_TEXT_END)+" "+
              TimeMSCtoString(this.GetProperty(PEND_REQ_PROP_TIME_CREATE)+this.GetProperty(PEND_REQ_PROP_WAITING)*this.GetProperty(PEND_REQ_PROP_TOTAL));
   //---
   string message=CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_STATUS_CLOSE)+": "+
   "/n- "+params+", "+price+pos_by+
   "/n- "+time+", "+attempts+", "+wait+", "+end+"/n";
   ::Print(message);
  }
//+------------------------------------------------------------------+

下挂单的延后请求对象类 (PendReqPlace.mqh 类文件):

//+------------------------------------------------------------------+
//|                                                 PendReqPlace.mqh |
//|                        Copyright 2019, MetaQuotes Software Corp. |
//|                             https://mql5.com/en/users/artmedia70 |
//+------------------------------------------------------------------+
#property copyright "Copyright 2019, MetaQuotes Software Corp."
#property link      "https://mql5.com/en/users/artmedia70"
#property version   "1.00"
//+------------------------------------------------------------------+
//| Include files                                                    |
//+------------------------------------------------------------------+
#include "PendRequest.mqh"
//+------------------------------------------------------------------+
//| Pending request to place a pending order                         |
//+------------------------------------------------------------------+
class CPendReqPlace : public CPendRequest
  {
public:
//--- Constructor
                     CPendReqPlace(const uchar id,
                                   const double price,
                                   const ulong time,
                                   const MqlTradeRequest &request,
                                   const int retcode) : CPendRequest(PEND_REQ_STATUS_PLACE,id,price,time,request,retcode) {}
                                  
//--- Supported deal properties (1) real, (2) integer
   virtual bool      SupportProperty(ENUM_PEND_REQ_PROP_INTEGER property);
   virtual bool      SupportProperty(ENUM_PEND_REQ_PROP_DOUBLE property);
   virtual bool      SupportProperty(ENUM_PEND_REQ_PROP_STRING property);
//--- Display a brief message with request data in the journal
   virtual void      PrintShort(void);
  };
//+------------------------------------------------------------------+
//| Return 'true' if an order supports a passed                      |
//| integer property, otherwise return 'false'                       |
//+------------------------------------------------------------------+
bool CPendReqPlace::SupportProperty(ENUM_PEND_REQ_PROP_INTEGER property)
  {
   if(property==PEND_REQ_PROP_MQL_REQ_ORDER        ||
      property==PEND_REQ_PROP_MQL_REQ_POSITION     ||
      property==PEND_REQ_PROP_MQL_REQ_POSITION_BY  ||
      property==PEND_REQ_PROP_MQL_REQ_DEVIATION
     ) return false;
   return true;
  }
//+------------------------------------------------------------------+
//| Return 'true' if an order supports a passed                      |
//| real property, otherwise return 'false'                          |
//+------------------------------------------------------------------+
bool CPendReqPlace::SupportProperty(ENUM_PEND_REQ_PROP_DOUBLE property)
  {
   return true;
  }
//+------------------------------------------------------------------+
//| Return 'true' if an order supports a passed                      |
//| string property, otherwise return 'false'                        |
//+------------------------------------------------------------------+
bool CPendReqPlace::SupportProperty(ENUM_PEND_REQ_PROP_STRING property)
  {
   return true;
  }
//+------------------------------------------------------------------+
//| Display a brief message with request data in the journal         |
//+------------------------------------------------------------------+
void CPendReqPlace::PrintShort(void)
  {
   string params=this.GetProperty(PEND_REQ_PROP_MQL_REQ_SYMBOL)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_VOLUME),this.m_digits_lot)+" "+
                 OrderTypeDescription((ENUM_ORDER_TYPE)this.GetProperty(PEND_REQ_PROP_MQL_REQ_TYPE));
   string price=CMessage::Text(MSG_LIB_TEXT_REQUEST_PRICE)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_PRICE),this.m_digits);
   string stoplimit=this.GetProperty(PEND_REQ_PROP_MQL_REQ_STOPLIMIT)>0 ? ", "+CMessage::Text(MSG_LIB_TEXT_REQUEST_STOPLIMIT)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_STOPLIMIT),this.m_digits) : "";
   string sl=this.GetProperty(PEND_REQ_PROP_MQL_REQ_SL)>0 ? ", "+CMessage::Text(MSG_LIB_TEXT_REQUEST_SL)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_SL),this.m_digits) : "";
   string tp=this.GetProperty(PEND_REQ_PROP_MQL_REQ_TP)>0 ? ", "+CMessage::Text(MSG_LIB_TEXT_REQUEST_TP)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_TP),this.m_digits) : "";
   string time=this.IDDescription()+", "+CMessage::Text(MSG_LIB_TEXT_CREATED)+" "+TimeMSCtoString(this.GetProperty(PEND_REQ_PROP_TIME_CREATE));
   string attempts=CMessage::Text(MSG_LIB_TEXT_ATTEMPTS)+" "+(string)this.GetProperty(PEND_REQ_PROP_TOTAL);
   string wait=CMessage::Text(MSG_LIB_TEXT_WAIT)+" "+::TimeToString(this.GetProperty(PEND_REQ_PROP_WAITING)/1000,TIME_SECONDS);
   string end=CMessage::Text(MSG_LIB_TEXT_END)+" "+
              TimeMSCtoString(this.GetProperty(PEND_REQ_PROP_TIME_CREATE)+this.GetProperty(PEND_REQ_PROP_WAITING)*this.GetProperty(PEND_REQ_PROP_TOTAL));
   //---
   string message=CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_STATUS_PLACE)+": "+
   "/n- "+params+", "+price+stoplimit+sl+tp+
   "/n- "+time+", "+attempts+", "+wait+", "+end+"/n";
   ::Print(message);
  }
//+------------------------------------------------------------------+

修改已下达挂单之参数的延后请求对象类 (PendReqModify.mqh 类文件):

//+------------------------------------------------------------------+
//|                                                PendReqModify.mqh |
//|                        Copyright 2019, MetaQuotes Software Corp. |
//|                             https://mql5.com/en/users/artmedia70 |
//+------------------------------------------------------------------+
#property copyright "Copyright 2019, MetaQuotes Software Corp."
#property link      "https://mql5.com/en/users/artmedia70"
#property version   "1.00"
//+------------------------------------------------------------------+
//| Include files                                                    |
//+------------------------------------------------------------------+
#include "PendRequest.mqh"
//+------------------------------------------------------------------+
//| Pending request to modify pending order parameters               |
//+------------------------------------------------------------------+
class CPendReqModify : public CPendRequest
  {
public:
//--- Constructor
                     CPendReqModify(const uchar id,
                                    const double price,
                                    const ulong time,
                                    const MqlTradeRequest &request,
                                    const int retcode) : CPendRequest(PEND_REQ_STATUS_MODIFY,id,price,time,request,retcode) {}
                                  
//--- Supported deal properties (1) real, (2) integer
   virtual bool      SupportProperty(ENUM_PEND_REQ_PROP_INTEGER property);
   virtual bool      SupportProperty(ENUM_PEND_REQ_PROP_DOUBLE property);
   virtual bool      SupportProperty(ENUM_PEND_REQ_PROP_STRING property);
//--- Display a brief message with request data in the journal
   virtual void      PrintShort(void);
  };
//+------------------------------------------------------------------+
//| Return 'true' if an order supports a passed                      |
//| integer property, otherwise return 'false'                       |
//+------------------------------------------------------------------+
bool CPendReqModify::SupportProperty(ENUM_PEND_REQ_PROP_INTEGER property)
  {
   if(property==PEND_REQ_PROP_MQL_REQ_POSITION     ||
      property==PEND_REQ_PROP_MQL_REQ_POSITION_BY  ||
      property==PEND_REQ_PROP_MQL_REQ_DEVIATION
     ) return false;
   return true;
  }
//+------------------------------------------------------------------+
//| Return 'true' if an order supports a passed                      |
//| real property, otherwise return 'false'                          |
//+------------------------------------------------------------------+
bool CPendReqModify::SupportProperty(ENUM_PEND_REQ_PROP_DOUBLE property)
  {
   return(property==PEND_REQ_PROP_MQL_REQ_VOLUME ? false : true);
  }
//+------------------------------------------------------------------+
//| Return 'true' if an order supports a passed                      |
//| string property, otherwise return 'false'                        |
//+------------------------------------------------------------------+
bool CPendReqModify::SupportProperty(ENUM_PEND_REQ_PROP_STRING property)
  {
   return true;
  }
//+------------------------------------------------------------------+
//| Display a brief message with request data in the journal         |
//+------------------------------------------------------------------+
void CPendReqModify::PrintShort(void)
  {
   string params=this.GetProperty(PEND_REQ_PROP_MQL_REQ_SYMBOL)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_VOLUME),this.m_digits_lot)+" "+
                 OrderTypeDescription((ENUM_ORDER_TYPE)this.GetProperty(PEND_REQ_PROP_MQL_REQ_TYPE))+" #"+(string)this.GetProperty(PEND_REQ_PROP_MQL_REQ_ORDER);
   string price=CMessage::Text(MSG_LIB_TEXT_REQUEST_PRICE)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_PRICE),this.m_digits);
   string stoplimit=this.GetProperty(PEND_REQ_PROP_MQL_REQ_STOPLIMIT)>0 ? ", "+CMessage::Text(MSG_LIB_TEXT_REQUEST_STOPLIMIT)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_STOPLIMIT),this.m_digits) : "";
   string sl=this.GetProperty(PEND_REQ_PROP_MQL_REQ_SL)>0 ? ", "+CMessage::Text(MSG_LIB_TEXT_REQUEST_SL)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_SL),this.m_digits) : "";
   string tp=this.GetProperty(PEND_REQ_PROP_MQL_REQ_TP)>0 ? ", "+CMessage::Text(MSG_LIB_TEXT_REQUEST_TP)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_TP),this.m_digits) : "";
   string expiration=this.GetProperty(PEND_REQ_PROP_MQL_REQ_EXPIRATION)>0 ? this.MqlReqExpirationDescription() : "";
   string type_filling=this.GetProperty(PEND_REQ_PROP_MQL_REQ_TYPE_FILLING)>WRONG_VALUE ? "/n- "+this.MqlReqTypeFillingDescription() : "";
   string type_time=this.GetProperty(PEND_REQ_PROP_MQL_REQ_TYPE_TIME)>WRONG_VALUE ? "/n- "+this.MqlReqTypeTimeDescription() : "";
   string time=this.IDDescription()+", "+CMessage::Text(MSG_LIB_TEXT_CREATED)+" "+TimeMSCtoString(this.GetProperty(PEND_REQ_PROP_TIME_CREATE));
   string attempts=CMessage::Text(MSG_LIB_TEXT_ATTEMPTS)+" "+(string)this.GetProperty(PEND_REQ_PROP_TOTAL);
   string wait=CMessage::Text(MSG_LIB_TEXT_WAIT)+" "+::TimeToString(this.GetProperty(PEND_REQ_PROP_WAITING)/1000,TIME_SECONDS);
   string end=CMessage::Text(MSG_LIB_TEXT_END)+" "+
              TimeMSCtoString(this.GetProperty(PEND_REQ_PROP_TIME_CREATE)+this.GetProperty(PEND_REQ_PROP_WAITING)*this.GetProperty(PEND_REQ_PROP_TOTAL));
   //---
   string message=CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_STATUS_MODIFY)+": "+
   "/n- "+params+", "+price+stoplimit+sl+tp+expiration+type_filling+type_time+
   "/n- "+time+", "+attempts+", "+wait+", "+end+"/n";
   ::Print(message);
  }
//+------------------------------------------------------------------+

删除已下达挂单的延后请求对象类 (PendReqRemove.mqh 类文件):

//+------------------------------------------------------------------+
//|                                                PendReqRemove.mqh |
//|                        Copyright 2019, MetaQuotes Software Corp. |
//|                             https://mql5.com/en/users/artmedia70 |
//+------------------------------------------------------------------+
#property copyright "Copyright 2019, MetaQuotes Software Corp."
#property link      "https://mql5.com/en/users/artmedia70"
#property version   "1.00"
//+------------------------------------------------------------------+
//| Include files                                                    |
//+------------------------------------------------------------------+
#include "PendRequest.mqh"
//+------------------------------------------------------------------+
//| Pending request to remove a pending order                        |
//+------------------------------------------------------------------+
class CPendReqRemove : public CPendRequest
  {
public:
//--- Constructor
                     CPendReqRemove(const uchar id,
                                    const double price,
                                    const ulong time,
                                    const MqlTradeRequest &request,
                                    const int retcode) : CPendRequest(PEND_REQ_STATUS_REMOVE,id,price,time,request,retcode) {}
                                  
//--- Supported deal properties (1) real, (2) integer
   virtual bool      SupportProperty(ENUM_PEND_REQ_PROP_INTEGER property);
   virtual bool      SupportProperty(ENUM_PEND_REQ_PROP_DOUBLE property);
   virtual bool      SupportProperty(ENUM_PEND_REQ_PROP_STRING property);
//--- Display a brief message with request data in the journal
   virtual void      PrintShort(void);
  };
//+------------------------------------------------------------------+
//| Return 'true' if an order supports a passed                      |
//| integer property, otherwise return 'false'                       |
//+------------------------------------------------------------------+
bool CPendReqRemove::SupportProperty(ENUM_PEND_REQ_PROP_INTEGER property)
  {
   return(property>PEND_REQ_PROP_MQL_REQ_ORDER ? false : true);
  }
//+------------------------------------------------------------------+
//| Return 'true' if an order supports a passed                      |
//| real property, otherwise return 'false'                          |
//+------------------------------------------------------------------+
bool CPendReqRemove::SupportProperty(ENUM_PEND_REQ_PROP_DOUBLE property)
  {
   return(property==PEND_REQ_PROP_PRICE_CREATE || property==PEND_REQ_PROP_MQL_REQ_PRICE ? true : false);
  }
//+------------------------------------------------------------------+
//| Return 'true' if an order supports a passed                      |
//| string property, otherwise return 'false'                        |
//+------------------------------------------------------------------+
bool CPendReqRemove::SupportProperty(ENUM_PEND_REQ_PROP_STRING property)
  {
   return true;
  }
//+------------------------------------------------------------------+
//| Display a brief message with request data in the journal         |
//+------------------------------------------------------------------+
void CPendReqRemove::PrintShort(void)
  {
   string params=this.GetProperty(PEND_REQ_PROP_MQL_REQ_SYMBOL)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_VOLUME),this.m_digits_lot)+" "+
                 OrderTypeDescription((ENUM_ORDER_TYPE)this.GetProperty(PEND_REQ_PROP_MQL_REQ_TYPE))+" #"+(string)this.GetProperty(PEND_REQ_PROP_MQL_REQ_ORDER);
   string price=CMessage::Text(MSG_LIB_TEXT_REQUEST_PRICE)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_PRICE),this.m_digits);
   string stoplimit=this.GetProperty(PEND_REQ_PROP_MQL_REQ_STOPLIMIT)>0 ? ", "+CMessage::Text(MSG_LIB_TEXT_REQUEST_STOPLIMIT)+" "+::DoubleToString(this.GetProperty(PEND_REQ_PROP_MQL_REQ_STOPLIMIT),this.m_digits) : "";
   string time=this.IDDescription()+", "+CMessage::Text(MSG_LIB_TEXT_CREATED)+" "+TimeMSCtoString(this.GetProperty(PEND_REQ_PROP_TIME_CREATE));
   string attempts=CMessage::Text(MSG_LIB_TEXT_ATTEMPTS)+" "+(string)this.GetProperty(PEND_REQ_PROP_TOTAL);
   string wait=CMessage::Text(MSG_LIB_TEXT_WAIT)+" "+::TimeToString(this.GetProperty(PEND_REQ_PROP_WAITING)/1000,TIME_SECONDS);
   string end=CMessage::Text(MSG_LIB_TEXT_END)+" "+
              TimeMSCtoString(this.GetProperty(PEND_REQ_PROP_TIME_CREATE)+this.GetProperty(PEND_REQ_PROP_WAITING)*this.GetProperty(PEND_REQ_PROP_TOTAL));
   //---
   string message=CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_STATUS_REMOVE)+": "+
   "/n- "+params+", "+price+stoplimit+
   "/n- "+time+", "+attempts+", "+wait+", "+end+"/n";
   ::Print(message);
  }
//+------------------------------------------------------------------+

所有这些类之间最重要的区别在于，传递延后请求状态至父对象的构造函数 – 其为判断这些对象所执行交易操作何种类型的状态。 其余的类方法仅用于辅助目的，不会影响交易结果。

延后交易请求的新类至此创建完毕。
现在，我们需要从交易类文件中删除临时的延后请求类，并进行其他修改，从而可利用延后交易请求的新对象操作。

打开 Trading.mqh 并从清单中彻底删除之前的延后请求类:

//+------------------------------------------------------------------+
//|                                                      Trading.mqh |
//|                        Copyright 2019, MetaQuotes Software Corp. |
//|                             https://mql5.com/en/users/artmedia70 |
//+------------------------------------------------------------------+
#property copyright "Copyright 2019, MetaQuotes Software Corp."
#property link      "https://mql5.com/en/users/artmedia70"
#property version   "1.00"
//+------------------------------------------------------------------+
//| Include files                                                    |
//+------------------------------------------------------------------+
#include <Arrays/ArrayInt.mqh>
#include "Objects/Trade/TradeObj.mqh"
#include "Collections/AccountsCollection.mqh"
#include "Collections/SymbolsCollection.mqh"
#include "Collections/MarketCollection.mqh"
#include "Collections/HistoryCollection.mqh"
#include "Collections/EventsCollection.mqh"
//+------------------------------------------------------------------+
//| Pending request object class                                     |
//+------------------------------------------------------------------+
class CPendingReq : public CObject
  {
private:
   MqlTradeRequest      m_request;                       // Trade request structure
   uchar                m_id;                            // Trading request ID
   int                  m_type;                          // Pending request type
   int                  m_retcode;                       // Result a request is based on
   double               m_price_create;                  // Price at the moment of a request generation
   ulong                m_time_create;                   // Request generation time
   ulong                m_time_activate;                 // Next attempt activation time
   ulong                m_waiting_msc;                   // Waiting time between requests
   uchar                m_current_attempt;               // Current attempt index
   uchar                m_total_attempts;                // Number of attempts
//--- Copy trading request data
   void                 CopyRequest(const MqlTradeRequest &request)  { this.m_request=request;        }
//--- Compare CPendingReq objects by IDs
   virtual int          Compare(const CObject *node,const int mode=0) const;

public:
//--- Return (1) the request structure, (2) the price at the moment of the request generation,
//--- (3) request generation time, (4) next attempt activation time,
//--- (5) waiting time between requests, (6) current attempt index,
//--- (7) number of attempts, (8) request ID
//--- (9) result a request is based on,
//--- (10) order ticket, (11) position ticket, (12) trading operation type
   MqlTradeRequest      MqlRequest(void)                       const { return this.m_request;         }
   double               PriceCreate(void)                      const { return this.m_price_create;    }
   ulong                TimeCreate(void)                       const { return this.m_time_create;     }
   ulong                TimeActivate(void)                     const { return this.m_time_activate;   }
   ulong                WaitingMSC(void)                       const { return this.m_waiting_msc;     }
   uchar                CurrentAttempt(void)                   const { return this.m_current_attempt; }
   uchar                TotalAttempts(void)                    const { return this.m_total_attempts;  }
   uchar                ID(void)                               const { return this.m_id;              }
   int                  Retcode(void)                          const { return this.m_retcode;         }
   ulong                Order(void)                            const { return this.m_request.order;   }
   ulong                Position(void)                         const { return this.m_request.position;}
   ENUM_TRADE_REQUEST_ACTIONS Action(void)                     const { return this.m_request.action;  }

//--- Set (1) the price when creating a request, (2) request creation time,
//--- (3) current attempt time, (4) waiting time between requests,
//--- (5) current attempt index, (6) number of attempts, (7) ID,
//--- (8) order ticket, (9) position ticket
   void                 SetPriceCreate(const double price)           { this.m_price_create=price;     }
   void                 SetTimeCreate(const ulong time)              { this.m_time_create=time;       }
   void                 SetTimeActivate(const ulong time)            { this.m_time_activate=time;     }
   void                 SetWaitingMSC(const ulong miliseconds)       { this.m_waiting_msc=miliseconds;}
   void                 SetCurrentAttempt(const uchar number)        { this.m_current_attempt=number; }
   void                 SetTotalAttempts(const uchar number)         { this.m_total_attempts=number;  }
   void                 SetID(const uchar id)                        { this.m_id=id;                  }
   void                 SetOrder(const ulong ticket)                 { this.m_request.order=ticket;   }
   void                 SetPosition(const ulong ticket)              { this.m_request.position=ticket;}
   
//--- Return the description of the (1) request structure, (2) the price at the moment of the request generation,
//--- (3) request generation time, (4) current attempt time,
//--- (5) waiting time between requests, (6) current attempt index,
//--- (7) number of attempts, (8) request ID
   string               MqlRequestDescription(void)            const { return RequestActionDescription(this.m_request); }
   string               TypeDescription(void)                  const
                          { 
                           return CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_TYPE) +
                             (this.Type()==PENDING_REQUEST_ID_TYPE_ERR           ?
                              CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_BY_ERROR) :
                              CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_BY_REQUEST)
                             );
                          }
   string               PriceCreateDescription(void)           const 
                          {
                           return CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_PRICE_CREATE)+": "+
                                  ::DoubleToString(this.PriceCreate(),(int)::SymbolInfoInteger(this.m_request.symbol,SYMBOL_DIGITS));
                          }
   string               TimeCreateDescription(void)            const { return CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_TIME_CREATE)+TimeMSCtoString(this.TimeCreate());    }
   string               TimeActivateDescription(void)          const { return CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_TIME_ACTIVATE)+TimeMSCtoString(this.TimeActivate());}
   string               WaitingMSCDescription(void)            const { return CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_WAITING)+(string)this.WaitingMSC();                 }
   string               CurrentAttemptDescription(void)        const 
                          {
                           return
                             (CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_CURRENT_ATTEMPT)+
                              (this.CurrentAttempt()==0 ? CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_WAITING_ONSET) : (string)this.CurrentAttempt())
                             );
                          }
   string               TotalAttemptsDescription(void)         const { return CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_TOTAL_ATTEMPTS)+(string)this.TotalAttempts();       }
   string               IdDescription(void)                    const { return CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_ID)+"#"+(string)this.ID();                          }
   string               RetcodeDescription(void)               const { return CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_RETCODE)+(string)this.Retcode();                    }
   string               ReasonDescription(void)                const { return CMessage::Text(this.m_retcode);  }

//--- Return a request type
   virtual int          Type(void)                             const { return this.m_type;   }
//--- Display request data in the journal
   void                 Print(void);
//--- Constructors
                        CPendingReq(void){;}
                        CPendingReq(const uchar id,const double price,const ulong time,const MqlTradeRequest &request,const int retcode);
  };
//+------------------------------------------------------------------+
//| Parametric constructor                                           |
//+------------------------------------------------------------------+
CPendingReq::CPendingReq(const uchar id,const double price,const ulong time,const MqlTradeRequest &request,const int retcode) : m_price_create(price),
                                                                                                                                m_time_create(time),
                                                                                                                                m_id(id),
                                                                                                                                m_retcode(retcode)
  {
   this.CopyRequest(request);
   this.m_type=(retcode>0 ? PENDING_REQUEST_ID_TYPE_ERR : PENDING_REQUEST_ID_TYPE_REQ);
  }
//+------------------------------------------------------------------+
//| Compare CPendingReq objects by properties                        |
//+------------------------------------------------------------------+
int CPendingReq::Compare(const CObject *node,const int mode=0) const
  {
   const CPendingReq *compared_req=node;
   return
     (
      //--- Compare by ID
      mode==SORT_BY_PEND_REQ_ID        ?  
      (this.ID()>compared_req.ID()     ? 1 : this.ID()<compared_req.ID() ? -1 : 0)     :
      //--- Compare by type
      mode==SORT_BY_PEND_REQ_TYPE      ?  
      (this.Type()>compared_req.Type() ? 1 : this.Type()<compared_req.Type() ? -1 : 0) :
      //--- Compare by ticket
      (
       //--- modifying position sl, tp, opening/closing a position or closing by an opposite one
       this.m_request.action==TRADE_ACTION_SLTP    || this.m_request.action==TRADE_ACTION_DEAL     || this.m_request.action==TRADE_ACTION_CLOSE_BY ?
       (this.m_request.position>compared_req.m_request.position ? 1 : this.m_request.position<compared_req.m_request.position ? -1 : 0)            :
       //--- modifying parameters, placing/removing a pending order
       this.m_request.action==TRADE_ACTION_MODIFY  || this.m_request.action==TRADE_ACTION_PENDING  || this.m_request.action==TRADE_ACTION_REMOVE   ?
       (this.m_request.order>compared_req.m_request.order ? 1 : this.m_request.order<compared_req.m_request.order ? -1 : 0)                        : 
       //--- otherwise
       0
      )
     );
  }
//+------------------------------------------------------------------+
//| Display request data in the journal                              |
//+------------------------------------------------------------------+
void CPendingReq::Print(void)
  {
   string action=" - "+RequestActionDescription(this.m_request)+"/n";
   string symbol="",order="",volume="",price="",stoplimit="",sl="",tp="",deviation="",type="",type_filling="";
   string type_time="",expiration="",position="",position_by="",magic="",comment="",request_data="";
   string type_req=" - "+this.TypeDescription()+"/n";
   
   if(this.m_request.action==TRADE_ACTION_DEAL)
     {
      symbol=" - "+RequestSymbolDescription(this.m_request)+"/n";
      volume=" - "+RequestVolumeDescription(this.m_request)+"/n";
      price=" - "+RequestPriceDescription(this.m_request)+"/n";
      sl=" - "+RequestStopLossDescription(this.m_request)+"/n";
      tp=" - "+RequestTakeProfitDescription(this.m_request)+"/n";
      deviation=" - "+RequestDeviationDescription(this.m_request)+"/n";
      type=" - "+RequestTypeDescription(this.m_request)+"/n";
      type_filling=" - "+RequestTypeFillingDescription(this.m_request)+"/n";
      magic=" - "+RequestMagicDescription(this.m_request)+"/n";
      comment=" - "+RequestCommentDescription(this.m_request)+"/n";
      request_data=
        ("================== "+
         CMessage::Text(MSG_LIB_TEXT_REQUEST_DATAS)+" ==================/n"+
         action+symbol+volume+price+sl+tp+deviation+type+type_filling+magic+comment+
         " ==================/n"
        );
     }
   else if(this.m_request.action==TRADE_ACTION_SLTP)
     {
      symbol=" - "+RequestSymbolDescription(this.m_request)+"/n";
      sl=" - "+RequestStopLossDescription(this.m_request)+"/n";
      tp=" - "+RequestTakeProfitDescription(this.m_request)+"/n";
      position=" - "+RequestPositionDescription(this.m_request)+"/n";
      request_data=
        ("================== "+
         CMessage::Text(MSG_LIB_TEXT_REQUEST_DATAS)+" ==================/n"+
         action+symbol+sl+tp+position+
         " ==================/n"
        );
     }
   else if(this.m_request.action==TRADE_ACTION_PENDING)
     {
      symbol=" - "+RequestSymbolDescription(this.m_request)+"/n";
      volume=" - "+RequestVolumeDescription(this.m_request)+"/n";
      price=" - "+RequestPriceDescription(this.m_request)+"/n";
      stoplimit=" - "+RequestStopLimitDescription(this.m_request)+"/n";
      sl=" - "+RequestStopLossDescription(this.m_request)+"/n";
      tp=" - "+RequestTakeProfitDescription(this.m_request)+"/n";
      type=" - "+RequestTypeDescription(this.m_request)+"/n";
      type_filling=" - "+RequestTypeFillingDescription(this.m_request)+"/n";
      type_time=" - "+RequestTypeTimeDescription(this.m_request)+"/n";
      expiration=" - "+RequestExpirationDescription(this.m_request)+"/n";
      magic=" - "+RequestMagicDescription(this.m_request)+"/n";
      comment=" - "+RequestCommentDescription(this.m_request)+"/n";
      request_data=
        ("================== "+
         CMessage::Text(MSG_LIB_TEXT_REQUEST_DATAS)+" ==================/n"+
         action+symbol+volume+price+stoplimit+sl+tp+type+type_filling+type_time+expiration+magic+comment+
         " ==================/n"
        );
     }
   else if(this.m_request.action==TRADE_ACTION_MODIFY)
     {
      order=" - "+RequestOrderDescription(this.m_request)+"/n";
      price=" - "+RequestPriceDescription(this.m_request)+"/n";
      sl=" - "+RequestStopLossDescription(this.m_request)+"/n";
      tp=" - "+RequestTakeProfitDescription(this.m_request)+"/n";
      type_time=" - "+RequestTypeTimeDescription(this.m_request)+"/n";
      expiration=" - "+RequestExpirationDescription(this.m_request)+"/n";
      request_data=
        ("================== "+
         CMessage::Text(MSG_LIB_TEXT_REQUEST_DATAS)+" ==================/n"+
         action+order+price+sl+tp+type_time+expiration+
         " ==================/n"
        );
     }
   else if(this.m_request.action==TRADE_ACTION_REMOVE)
     {
      order=" - "+RequestOrderDescription(this.m_request)+"/n";
      request_data=
        ("================== "+
         CMessage::Text(MSG_LIB_TEXT_REQUEST_DATAS)+" ==================/n"+
         action+order+
         " ==================/n"
        );
     }
   else if(this.m_request.action==TRADE_ACTION_CLOSE_BY)
     {
      position=" - "+RequestPositionDescription(this.m_request)+"/n";
      position_by=" - "+RequestPositionByDescription(this.m_request)+"/n";
      magic=" - "+RequestMagicDescription(this.m_request)+"/n";
      request_data=
        ("================== "+
         CMessage::Text(MSG_LIB_TEXT_REQUEST_DATAS)+" ==================/n"+
         action+position+position_by+magic+
         " ==================/n"
        );
     }
   string datas=
     (
      " - "+this.TypeDescription()+"/n"+
      " - "+this.IdDescription()+"/n"+
      " - "+this.RetcodeDescription()+" /""+this.ReasonDescription()+"/"/n"+
      " - "+this.TimeCreateDescription()+"/n"+
      " - "+this.PriceCreateDescription()+"/n"+
      " - "+this.TimeActivateDescription()+"/n"+
      " - "+this.WaitingMSCDescription()+" ("+TimeToString(this.WaitingMSC()/1000,TIME_MINUTES|TIME_SECONDS)+")"+"/n"+
      " - "+this.CurrentAttemptDescription()+"/n"+
      " - "+this.TotalAttemptsDescription()+"/n"
     );
   ::Print("================== ",CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_DATAS)," ==================/n",datas,request_data);
  }
//+------------------------------------------------------------------+
//+------------------------------------------------------------------+
//| Trading class                                                    |
//+------------------------------------------------------------------+
class CTrading
  {

为了令交易类看到延后请求新类的对象，将它们连接到交易类文件清单：

//+------------------------------------------------------------------+
//|                                                      Trading.mqh |
//|                        Copyright 2019, MetaQuotes Software Corp. |
//|                             https://mql5.com/en/users/artmedia70 |
//+------------------------------------------------------------------+
#property copyright "Copyright 2019, MetaQuotes Software Corp."
#property link      "https://mql5.com/en/users/artmedia70"
#property version   "1.00"
//+------------------------------------------------------------------+
//| Include files                                                    |
//+------------------------------------------------------------------+
#include <Arrays/ArrayInt.mqh>
#include "Objects/Trade/TradeObj.mqh"
#include "Objects/PendRequest/PendReqOpen.mqh"
#include "Objects/PendRequest/PendReqSLTP.mqh"
#include "Objects/PendRequest/PendReqClose.mqh"
#include "Objects/PendRequest/PendReqPlace.mqh"
#include "Objects/PendRequest/PendReqModify.mqh"
#include "Objects/PendRequest/PendReqRemove.mqh"
#include "Collections/AccountsCollection.mqh"
#include "Collections/SymbolsCollection.mqh"
#include "Collections/MarketCollection.mqh"
#include "Collections/HistoryCollection.mqh"
#include "Collections/EventsCollection.mqh"
//+------------------------------------------------------------------+

现在，创建新延后请求的方法会另外传递已创建交易请求的状态。
在方法声明里加入状态:

//--- Create a pending request
   bool                 CreatePendingRequest(const ENUM_PEND_REQ_STATUS status,
                                             const uchar id,
                                             const uchar attempts,
                                             const ulong wait,
                                             const MqlTradeRequest &request,
                                             const int retcode,
                                             CSymbol *symbol_obj);

另外，修复实现新延后请求的方法：

//+------------------------------------------------------------------+
//| Create a pending request                                         |
//+------------------------------------------------------------------+
bool CTrading::CreatePendingRequest(const ENUM_PEND_REQ_STATUS status,
                                    const uchar id,
                                    const uchar attempts,
                                    const ulong wait,
                                    const MqlTradeRequest &request,
                                    const int retcode,
                                    CSymbol *symbol_obj)
  {
   //--- Create a new pending request object depending on a request status
   CPendRequest *req_obj=NULL;
   switch(status)
     {
      case PEND_REQ_STATUS_OPEN     : req_obj=new CPendReqOpen(id,symbol_obj.BidLast(),symbol_obj.Time(),request,retcode);    break;
      case PEND_REQ_STATUS_CLOSE    : req_obj=new CPendReqClose(id,symbol_obj.BidLast(),symbol_obj.Time(),request,retcode);   break;
      case PEND_REQ_STATUS_SLTP     : req_obj=new CPendReqSLTP(id,symbol_obj.BidLast(),symbol_obj.Time(),request,retcode);    break;
      case PEND_REQ_STATUS_PLACE    : req_obj=new CPendReqPlace(id,symbol_obj.BidLast(),symbol_obj.Time(),request,retcode);   break;
      case PEND_REQ_STATUS_REMOVE   : req_obj=new CPendReqRemove(id,symbol_obj.BidLast(),symbol_obj.Time(),request,retcode);  break;
      case PEND_REQ_STATUS_MODIFY   : req_obj=new CPendReqModify(id,symbol_obj.BidLast(),symbol_obj.Time(),request,retcode);  break;
      default: req_obj=NULL;
        break;
     }
   if(req_obj==NULL)
     {
      if(this.m_log_level>LOG_LEVEL_NO_MSG)
         ::Print(DFUN,CMessage::Text(MSG_LIB_TEXT_FAILING_CREATE_PENDING_REQ));
      return false;
     }
   //--- If failed to add the request to the list, display the appropriate message,
   //--- remove the created object and return 'false'
   if(!this.m_list_request.Add(req_obj))
     {
      if(this.m_log_level>LOG_LEVEL_NO_MSG)
         ::Print(DFUN,CMessage::Text(MSG_LIB_TEXT_FAILING_CREATE_PENDING_REQ));
      delete req_obj;
      return false;
     }
   //--- Filled in the fields of a successfully created object by the values passed to the method
   req_obj.SetTimeActivate(symbol_obj.Time()+wait);
   req_obj.SetWaitingMSC(wait);
   req_obj.SetCurrentAttempt(0);
   req_obj.SetTotalAttempts(attempts);
   
   //--- Display a brief description of a created pending request
   if(this.m_log_level>LOG_LEVEL_NO_MSG)
     {
      ::Print(CMessage::Text(MSG_LIB_TEXT_PEND_REQUEST_CREATED)," #",req_obj.ID(),":");
      req_obj.PrintShort();
     }
   //--- successful
   return true;
  }
//+------------------------------------------------------------------+

现在，该方法额外接收已创建的延后请求对象的状态。
以前，延后请求对象类型是 CPendingReq 类。 现在，该类已被彻底删除，故此当前我们有 CPendRequest 延后请求对象及其后代的新类。
因此，当创建一个空对象时，我们利用 CPendRequest 基准抽象请求的新对象。
接下来，根据传递给方法的状态，创建相应的新延后请求对象。
如果成功创建对象，日志里将显示一条简短消息，其中包含已创建延后交易请求的参数。

鉴于现在有了延后请求类的新对象，因此在交易类清单中，将所有出现的 CPendingReq 类替换为 CPendRequest 。 利用 Ctrl+H（搜索并替换）可以便捷地完成此操作。

在创建新延后请求对象时，它们将获得将要进行的交易操作的更多有关数据。 基本上，这是必需在日志中显示的。 在创建延后请求的新对象时，通过将其他数据写入交易请求结构来传递数据。

在开仓方法的延后请求创建模块里指定所创建请求的状态：

      //--- If the check result is "waiting" - set the last error code to the return structure and display the message in the journal,
      //--- create a pending request and return 'false'
      if(method>ERROR_CODE_PROCESSING_METHOD_REFRESH)
        {
         //--- If the trading request magic number, has no pending request ID
         if(this.GetPendReqID((uint)magic)==0)
           {
            //--- Play the error sound
            if(this.IsUseSounds())
               trade_obj.PlaySoundError(action,order_type);
            //--- set the last error code to the return structure
            int code=this.m_list_errors.At(this.m_list_errors.Total()-1);
            if(code!=NULL)
              {
               if(code==MSG_LIB_TEXT_TERMINAL_NOT_TRADE_ENABLED || code==MSG_LIB_TEXT_EA_NOT_TRADE_ENABLED)
                  code=10027;
               trade_obj.SetResultRetcode(code);
               trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
              }
            //--- Waiting time in milliseconds:
            //--- for the "Wait and repeat" handling method, the waiting value corresponds to the 'method' value,
            ulong wait=method;
            //--- Look for the least of the possible IDs. If failed to find
            //--- or in case of an error while updating the current symbol data, return 'false'
            int id=this.GetFreeID();
            if(id<1 || !symbol_obj.RefreshRates())
               return false;
            //--- Write the pending request object ID to the magic number and fill in the remaining unfilled fields of the trading request structure
            uint mn=(magic==ULONG_MAX ? (uint)trade_obj.GetMagic() : (uint)magic);
            this.SetPendReqID((uchar)id,mn);
            this.m_request.magic=mn;
            this.m_request.action=TRADE_ACTION_DEAL;
            this.m_request.symbol=symbol_obj.Name();
            this.m_request.type=order_type;
            //--- Set the number of trading attempts and create a pending request
            uchar attempts=(this.m_total_try < 1 ? 1 : this.m_total_try);
            this.CreatePendingRequest(PEND_REQ_STATUS_OPEN,(uchar)id,attempts,wait,this.m_request,trade_obj.GetResultRetcode(),symbol_obj);
           }
         return false;
        }

在修改持仓之止价单的方法中，即在延后请求创建模块里，添加通过结构传递订单类型和仓量至请求对象，以及设置所创建请求的状态：

      //--- If the check result is "waiting" - set the last error code to the return structure and display the message in the journal,
      //--- create a pending request and return 'false'
      if(method>ERROR_CODE_PROCESSING_METHOD_REFRESH)
        {
         //--- If the pending request object with the position ticket is not present in the list
         if(this.GetIndexPendingRequestByPosition(ticket)==WRONG_VALUE)
           {
            //--- Play the error sound
            if(this.IsUseSounds())
               trade_obj.PlaySoundError(action,order_type,(sl<0 ? false : true),(tp<0 ? false : true));
            //--- set the last error code to the return structure
            int code=this.m_list_errors.At(this.m_list_errors.Total()-1);
            if(code!=NULL)
              {
               if(code==MSG_LIB_TEXT_TERMINAL_NOT_TRADE_ENABLED || code==MSG_LIB_TEXT_EA_NOT_TRADE_ENABLED)
                  code=10027;
               trade_obj.SetResultRetcode(code);
               trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
              }
            //--- Waiting time in milliseconds:
            //--- for the "Wait and repeat" handling method, the waiting value corresponds to the 'method' value,
            //--- for the "Create a pending request" handling method - till there is a zero waiting time
            ulong wait=method;
            //--- Look for the least of the possible IDs. If failed to find
            //--- or in case of an error while updating the current symbol data, return 'false'
            int id=this.GetFreeID();
            if(id<1 || !symbol_obj.RefreshRates())
               return false;
            //--- Write a type of a conducted operation, as well as a symbol and a ticket of a modified position to the request structure
            this.m_request.action=TRADE_ACTION_SLTP;
            this.m_request.symbol=symbol_obj.Name();
            this.m_request.position=ticket;
            this.m_request.type=order_type;
            this.m_request.volume=order.Volume();
            //--- Set the number of trading attempts and create a pending request
            uchar attempts=(this.m_total_try < 1 ? 1 : this.m_total_try);
            this.CreatePendingRequest(PEND_REQ_STATUS_SLTP,(uchar)id,attempts,wait,this.m_request,trade_obj.GetResultRetcode(),symbol_obj);
           }
         return false;
        }

在平仓方法中，即在创建延后请求的模块里，添加通过结构传递订单类型和仓量至请求对象，以及设置所创建请求的状态：

      //--- If the check result is "waiting" - set the last error code to the return structure and display the message in the journal,
      //--- create a pending request and return 'false'
      if(method>ERROR_CODE_PROCESSING_METHOD_REFRESH)
        {
         //--- If the pending request object with the position ticket is not present in the list
         if(this.GetIndexPendingRequestByPosition(ticket)==WRONG_VALUE)
           {
            //--- Play the error sound
            if(this.IsUseSounds())
               trade_obj.PlaySoundError(action,order_type);
            //--- set the last error code to the return structure
            int code=this.m_list_errors.At(this.m_list_errors.Total()-1);
            if(code!=NULL)
              {
               if(code==MSG_LIB_TEXT_TERMINAL_NOT_TRADE_ENABLED || code==MSG_LIB_TEXT_EA_NOT_TRADE_ENABLED)
                  code=10027;
               trade_obj.SetResultRetcode(code);
               trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
              }
            //--- Waiting time in milliseconds:
            //--- for the "Wait and repeat" handling method, the waiting value corresponds to the 'method' value,
            ulong wait=method;
            //--- Look for the least of the possible IDs. If failed to find
            //--- or in case of an error while updating the current symbol data, return 'false'
            int id=this.GetFreeID();
            if(id<1 || !symbol_obj.RefreshRates())
               return false;
            //--- Write the trading operation type, symbol, ticket and volume to the request structure
            this.m_request.action=TRADE_ACTION_DEAL;
            this.m_request.symbol=symbol_obj.Name();
            this.m_request.position=ticket;
            this.m_request.volume=(volume==WRONG_VALUE || volume>order.Volume() ? order.Volume() : volume);
            this.m_request.type=order_type;
            //--- Set the number of trading attempts and create a pending request
            uchar attempts=(this.m_total_try < 1 ? 1 : this.m_total_try);
            this.CreatePendingRequest(PEND_REQ_STATUS_CLOSE,(uchar)id,attempts,wait,this.m_request,trade_obj.GetResultRetcode(),symbol_obj);
           }
         return false;

在方法里仓量可能为负（-1），表示彻底平仓。 如果将仓量指定为某个数值，则该仓位将部分平仓。 向服务器发送交易请求时，所有这些操作都在交易品种的基准交易对象中进行。
在此，我们立即检查传递给该方法的交易量，并将所需交易量设置到交易请求结构。

在按逆向方式平仓的方法中，在创建延后请求的木块里，添加通过结构传递订单类型和仓量至请求对象，以及设置所创建请求的状态：

      //--- If the check result is "waiting" - set the last error code to the return structure and display the message in the journal,
      //--- create a pending request and return 'false'
      if(method>ERROR_CODE_PROCESSING_METHOD_REFRESH)
        {
         //--- If the pending request object with the position ticket is not present in the list
         if(this.GetIndexPendingRequestByPosition(ticket)==WRONG_VALUE)
           {
            //--- Play the error sound
            if(this.IsUseSounds())
               trade_obj_pos.PlaySoundError(action,order_type);
            //--- set the last error code to the return structure
            int code=this.m_list_errors.At(this.m_list_errors.Total()-1);
            if(code!=NULL)
              {
               if(code==MSG_LIB_TEXT_TERMINAL_NOT_TRADE_ENABLED || code==MSG_LIB_TEXT_EA_NOT_TRADE_ENABLED)
                  code=10027;
               trade_obj_pos.SetResultRetcode(code);
               trade_obj_pos.SetResultComment(CMessage::Text(trade_obj_pos.GetResultRetcode()));
              }
            //--- Waiting time in milliseconds:
            //--- for the "Wait and repeat" handling method, the waiting value corresponds to the 'method' value,
            ulong wait=method;
            //--- Look for the least of the possible IDs. If failed to find
            //--- or in case of an error while updating the current symbol data, return 'false'
            int id=this.GetFreeID();
            if(id<1 || !symbol_obj.RefreshRates())
               return false;
            //--- Write the trading operation type, symbol and tickets of two positions to the request structure
            this.m_request.action=TRADE_ACTION_CLOSE_BY;
            this.m_request.symbol=symbol_obj.Name();
            this.m_request.position=ticket;
            this.m_request.position_by=ticket_by;
            this.m_request.type=order_type;
            this.m_request.volume=order.Volume();
            //--- Set the number of trading attempts and create a pending request
            uchar attempts=(this.m_total_try < 1 ? 1 : this.m_total_try);
            this.CreatePendingRequest(PEND_REQ_STATUS_CLOSE,(uchar)id,attempts,wait,this.m_request,trade_obj_pos.GetResultRetcode(),symbol_obj);
           }
         return false;
        }

在下挂单方法的延后请求创建模块里指定所创建请求的状态：

      //--- If the check result is "waiting" - set the last error code to the return structure and display the message in the journal,
      //--- create a pending request and return 'false'
      if(method>ERROR_CODE_PROCESSING_METHOD_REFRESH)
        {
         //--- If the trading request magic number, has no pending request ID
         if(this.GetPendReqID((uint)magic)==0)
           {
            //--- Play the error sound
            if(this.IsUseSounds())
               trade_obj.PlaySoundError(action,order_type);
            //--- set the last error code to the return structure
            int code=this.m_list_errors.At(this.m_list_errors.Total()-1);
            if(code!=NULL)
              {
               if(code==MSG_LIB_TEXT_TERMINAL_NOT_TRADE_ENABLED || code==MSG_LIB_TEXT_EA_NOT_TRADE_ENABLED)
                  code=10027;
               trade_obj.SetResultRetcode(code);
               trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
              }
            //--- Waiting time in milliseconds:
            //--- for the "Wait and repeat" handling method, the waiting value corresponds to the 'method' value,
            //--- for the "Create a pending request" handling method - till there is a zero waiting time
            ulong wait=method;
            //--- Look for the least of the possible IDs. If failed to find
            //--- or in case of an error while updating the current symbol data, return 'false'
            int id=this.GetFreeID();
            if(id<1 || !symbol_obj.RefreshRates())
               return false;
            //--- Write the request ID to the magic number, while a symbol name is set in the request structure,
            //--- trading operation and order types
            uint mn=(magic==ULONG_MAX ? (uint)trade_obj.GetMagic() : (uint)magic);
            this.SetPendReqID((uchar)id,mn);
            this.m_request.magic=mn;
            this.m_request.symbol=symbol_obj.Name();
            this.m_request.action=TRADE_ACTION_PENDING;
            this.m_request.type=order_type;
               //--- Set the number of trading attempts and create a pending request
            uchar attempts=(this.m_total_try < 1 ? 1 : this.m_total_try);
            this.CreatePendingRequest(PEND_REQ_STATUS_PLACE,(uchar)id,attempts,wait,this.m_request,trade_obj.GetResultRetcode(),symbol_obj);
           }
         return false;
        }

在修改挂单参数的方法中，即在其延后请求创建模块里，添加通过结构传递订单类型至请求对象，以及设置所创建请求的状态：

      //--- If the check result is "waiting" - set the last error code to the return structure and display the message in the journal,
      //--- create a pending request and return 'false'
      if(method>ERROR_CODE_PROCESSING_METHOD_REFRESH)
        {
         //--- If the pending request object with the order ticket is not present in the list
         if(this.GetIndexPendingRequestByOrder(ticket)==WRONG_VALUE)
           {
            //--- Play the error sound
            if(this.IsUseSounds())
               trade_obj.PlaySoundError(action,order_type,(sl<0 ? false : true),(tp<0 ? false : true),(price>0 || limit>0 ? true : false));
            //--- set the last error code to the return structure
            int code=this.m_list_errors.At(this.m_list_errors.Total()-1);
            if(code!=NULL)
              {
               if(code==MSG_LIB_TEXT_TERMINAL_NOT_TRADE_ENABLED || code==MSG_LIB_TEXT_EA_NOT_TRADE_ENABLED)
                  code=10027;
               trade_obj.SetResultRetcode(code);
               trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
              }
            //--- Waiting time in milliseconds:
            //--- for the "Wait and repeat" handling method, the waiting value corresponds to the 'method' value,
            //--- for the "Create a pending request" handling method - till there is a zero waiting time
            ulong wait=method;
            //--- Look for the least of the possible IDs. If failed to find
            //--- or in case of an error while updating the current symbol data, return 'false'
            int id=this.GetFreeID();
            if(id<1 || !symbol_obj.RefreshRates())
               return false;
            //--- Set the trading operation type, as well as modified order's symbol and ticket in the request structure
            this.m_request.action=TRADE_ACTION_MODIFY;
            this.m_request.symbol=symbol_obj.Name();
            this.m_request.order=ticket;
            this.m_request.type=order_type;
            //--- Set the number of trading attempts and create a pending request
            uchar attempts=(this.m_total_try < 1 ? 1 : this.m_total_try);
            this.CreatePendingRequest(PEND_REQ_STATUS_MODIFY,(uchar)id,attempts,wait,this.m_request,trade_obj.GetResultRetcode(),symbol_obj);
           }
         return false;
        }

在删除挂单的方法中，即在其延后请求创建模块里，添加传递订单类型和交易量及其价格，以及设置所创建请求的状态：

      //--- If the check result is "waiting" - set the last error code to the return structure and display the message in the journal,
      //--- create a pending request and return 'false'
      if(method>ERROR_CODE_PROCESSING_METHOD_REFRESH)
        {
         //--- If the pending request object with the order ticket is not present in the list
         if(this.GetIndexPendingRequestByOrder(ticket)==WRONG_VALUE)
           {
            //--- Play the error sound
            if(this.IsUseSounds())
               trade_obj.PlaySoundError(action,order_type);
            //--- set the last error code to the return structure
            int code=this.m_list_errors.At(this.m_list_errors.Total()-1);
            if(code!=NULL)
              {
               if(code==MSG_LIB_TEXT_TERMINAL_NOT_TRADE_ENABLED || code==MSG_LIB_TEXT_EA_NOT_TRADE_ENABLED)
                  code=10027;
               trade_obj.SetResultRetcode(code);
               trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
              }
            //--- Waiting time in milliseconds:
            //--- for the "Wait and repeat" handling method, the waiting value corresponds to the 'method' value,
            //--- for the "Create a pending request" handling method - till there is a zero waiting time
            ulong wait=method;
            //--- Look for the least of the possible IDs. If failed to find
            //--- or in case of an error while updating the current symbol data, return 'false'
            int id=this.GetFreeID();
            if(id<1 || !symbol_obj.RefreshRates())
               return false;
            //--- Set the trading operation type, as well as deleted order's symbol and ticket in the request structure
            this.m_request.action=TRADE_ACTION_REMOVE;
            this.m_request.symbol=symbol_obj.Name();
            this.m_request.order=ticket;
            this.m_request.type=order_type;
            this.m_request.volume=order.Volume();
            this.m_request.price=order.PriceOpen();
            //--- Set the number of trading attempts and create a pending request
            uchar attempts=(this.m_total_try < 1 ? 1 : this.m_total_try);
            this.CreatePendingRequest(PEND_REQ_STATUS_REMOVE,(uchar)id,attempts,wait,this.m_request,trade_obj.GetResultRetcode(),symbol_obj);
           }
         return false;
        }

每个交易方法都有两个这样的模块。 因此，我们要将修改依次插入到它们当中。

在搜索空闲 ID 并返回请求对象索引的方法中设置排序类型：

//+------------------------------------------------------------------+
//| Look for the first free pending request ID                       |
//+------------------------------------------------------------------+
int CTrading::GetFreeID(void)
  {
   int id=WRONG_VALUE;
   CPendRequest *element=new CPendRequest();
   if(element==NULL)
      return 0;
   for(int i=1;i<256;i++)
     {
      element.SetID((uchar)i);
      this.m_list_request.Sort(SORT_BY_PEND_REQ_ID);
      if(this.m_list_request.Search(element)==WRONG_VALUE)
        {
         id=i;
         break;
        }
     }
   delete element;
   return id;
  }
//+------------------------------------------------------------------+
//| Return the request object index in the list by ID                |
//+------------------------------------------------------------------+
int CTrading::GetIndexPendingRequestByID(const uchar id)
  {
   CPendRequest *req=new CPendRequest();
   if(req==NULL)
      return WRONG_VALUE;
   req.SetID(id);
   this.m_list_request.Sort(SORT_BY_PEND_REQ_ID);
   int index=this.m_list_request.Search(req);
   delete req;
   return index;
  }
//+------------------------------------------------------------------+
//| Return the request object index in the list by the order ticket  |
//+------------------------------------------------------------------+
int CTrading::GetIndexPendingRequestByOrder(const ulong ticket)
  {
   CPendRequest *req=new CPendRequest();
   if(req==NULL)
      return WRONG_VALUE;
   req.SetOrder(ticket);
   this.m_list_request.Sort(SORT_BY_PEND_REQ_MQL_REQ_ORDER);
   int index=this.m_list_request.Search(req);
   delete req;
   return index;
  }
//+-------------------------------------------------------------------+
//| Return the request object index in the list by the position ticket|
//+-------------------------------------------------------------------+
int CTrading::GetIndexPendingRequestByPosition(const ulong ticket)
  {
   CPendRequest *req=new CPendRequest();
   if(req==NULL)
      return WRONG_VALUE;
   req.SetPosition(ticket);
   this.m_list_request.Sort(SORT_BY_PEND_REQ_MQL_REQ_POSITION);
   int index=this.m_list_request.Search(req);
   delete req;
   return index;
  }
//+------------------------------------------------------------------+

为了按指定属性在列表里搜索对象，调用动态指向 CObject 类实例的 Search() 方法，我们需要应用基类的 Sort() 方法，并用 CArray 动态变量数组指定列表执行排序的类型，因为搜索仅在排序后的数组中进行。 这正是我们在此所做的。

现在，在类计时器中，改进日志显示的消息，在其中带上交易尝试次数。
替换代码

      //--- Set the attempt number in the request object
      req_obj.SetCurrentAttempt(uchar(req_obj.CurrentAttempt()+1));
      
      //--- Display the number of a trading attempt in the journal

      if(this.m_log_level>LOG_LEVEL_NO_MSG)
         ::Print(CMessage::Text(MSG_LIB_TEXT_REQUEST)+(string)req_obj.GetProperty(PEND_REQ_PROP_ID)+" "+CMessage::Text(MSG_LIB_TEXT_RE_TRY_N)+(string)req_obj.CurrentAttempt());
      
      //--- Depending on the type of action performed in the trading request 
      switch(request.action)
        {

为以下：

      //--- Set the attempt number in the request object
      req_obj.SetCurrentAttempt(uchar(req_obj.CurrentAttempt()+1));
      
      //--- Display the number of a trading attempt in the journal

      if(this.m_log_level>LOG_LEVEL_NO_MSG)
        {
         ::Print(CMessage::Text(MSG_LIB_TEXT_RE_TRY_N)+(string)req_obj.CurrentAttempt()+":");
         req_obj.PrintShort();
        }
      
      //--- Depending on the type of action performed in the trading request 
      switch(request.action)
        {

这为我们在日志里提供了有关下一次延后请求对象尝试进行交易的更多信息。

所有必要的修改至此完毕，如此函数库即可操控延后交易请求对象。

测试

为了测试新的延后请求对象，请使用上一篇文章中的 EA，并将其保存在 /MQL5/Experts/TestDoEasy/Part29/ 之下，命名为 TestDoEasyPart29.mq5。

我们需要做所有工作就是删除多/空持仓平仓一半时的多余检查，因为所有操作都是在交易类的交易方法中完成的。

在部分多头平仓的模块中，替换代码：

      //--- If the BUTT_CLOSE_BUY2 button is pressed: Close the half of the Buy with the maximum profit
      else if(button==EnumToString(BUTT_CLOSE_BUY2))
        {
         //--- Get the list of all open positions
         CArrayObj* list=engine.GetListMarketPosition();
         //--- Select only Buy positions from the list
         list=CSelect::ByOrderProperty(list,ORDER_PROP_TYPE,POSITION_TYPE_BUY,EQUAL);
         //--- Sort the list by profit considering commission and swap
         list.Sort(SORT_BY_ORDER_PROFIT_FULL);
         //--- Get the index of the Buy position with the maximum profit
         int index=CSelect::FindOrderMax(list,ORDER_PROP_PROFIT_FULL);
         if(index>WRONG_VALUE)
           {
            COrder* position=list.At(index);
            if(position!=NULL)
              {
               //--- If this is a hedge account, close the half of the Buy position by the ticket
               if(engine.IsHedge())
                  engine.ClosePositionPartially((ulong)position.Ticket(),position.Volume()/2.0);
               //--- If this is a netting account, open a Sell position with the half of the Buy position volume
               else
                  engine.OpenSell(NormalizeLot(position.Symbol(),position.Volume()/2.0),position.Symbol(),position.Magic(),position.StopLoss(),position.TakeProfit(),"Частичное закрытие Buy #"+(string)position.Ticket());
              }
           }
        }

为以下:

      //--- If the BUTT_CLOSE_BUY2 button is pressed: Close the half of the Buy with the maximum profit
      else if(button==EnumToString(BUTT_CLOSE_BUY2))
        {
         //--- Get the list of all open positions
         CArrayObj* list=engine.GetListMarketPosition();
         //--- Select only Buy positions from the list
         list=CSelect::ByOrderProperty(list,ORDER_PROP_TYPE,POSITION_TYPE_BUY,EQUAL);
         //--- Sort the list by profit considering commission and swap
         list.Sort(SORT_BY_ORDER_PROFIT_FULL);
         //--- Get the index of the Buy position with the maximum profit
         int index=CSelect::FindOrderMax(list,ORDER_PROP_PROFIT_FULL);
         if(index>WRONG_VALUE)
           {
            COrder* position=list.At(index);
            //--- Close the Buy position partially
            if(position!=NULL)
               engine.ClosePositionPartially((ulong)position.Ticket(),position.Volume()/2.0);
           }
        }

还有，以相同的方式重写部分空头平仓：

      //--- If the BUTT_CLOSE_SELL2 button is pressed: Close the half of the Sell with the maximum profit
      else if(button==EnumToString(BUTT_CLOSE_SELL2))
        {
         //--- Get the list of all open positions
         CArrayObj* list=engine.GetListMarketPosition();
         //--- Select only Sell positions from the list
         list=CSelect::ByOrderProperty(list,ORDER_PROP_TYPE,POSITION_TYPE_SELL,EQUAL);
         //--- Sort the list by profit considering commission and swap
         list.Sort(SORT_BY_ORDER_PROFIT_FULL);
         //--- Get the index of the Sell position with the maximum profit
         int index=CSelect::FindOrderMax(list,ORDER_PROP_PROFIT_FULL);
         if(index>WRONG_VALUE)
           {
            COrder* position=list.At(index);
            //--- Close the Sell position partially
            if(position!=NULL)
               engine.ClosePositionPartially((ulong)position.Ticket(),position.Volume()/2.0);
           }
        }

编译并启动 EA。

目前，我有四个有效的挂单。 我们禁用“自动交易”按钮，然后单击测试 EA 的 “Delete pending” 按钮以便删除所有挂单。 日志中会显示以下消息：

2019.12.19 04:25:04.385 CTrading::DeleteOrder: Invalid request:
2019.12.19 04:25:04.385 There is no permission to conduct trading operations in the terminal (the "AutoTrading" button is disabled)
2019.12.19 04:25:04.385 Correction of trade request parameters ...
2019.12.19 04:25:04.385 Pending request created #1:
2019.12.19 04:25:04.385 Pending request to remove a pending order: 
2019.12.19 04:25:04.385 - EURUSD 0.10 Pending order Buy Limit #497568391, Price 1.11076
2019.12.19 04:25:04.385 - Pending request ID: #1, Created 2019.12.18 23:25:01.920, Attempts 5, Wait 00:00:20, End 2019.12.18 23:26:41.920
2019.12.19 04:25:04.385 
2019.12.19 04:25:04.386 CTrading::DeleteOrder: Invalid request:
2019.12.19 04:25:04.386 There is no permission to conduct trading operations in the terminal (the "AutoTrading" button is disabled)
2019.12.19 04:25:04.386 Correction of trade request parameters ...
2019.12.19 04:25:04.386 Pending request created #2:
2019.12.19 04:25:04.386 Pending request to remove a pending order: 
2019.12.19 04:25:04.386 - EURUSD 0.10 Pending order Buy Limit #497563913, Price 1.11099
2019.12.19 04:25:04.386 - Pending request ID: #2, Created 2019.12.18 23:25:01.920, Attempts 5, Wait 00:00:20, End 2019.12.18 23:26:41.920
2019.12.19 04:25:04.386 
2019.12.19 04:25:04.386 CTrading::DeleteOrder: Invalid request:
2019.12.19 04:25:04.386 There is no permission to conduct trading operations in the terminal (the "AutoTrading" button is disabled)
2019.12.19 04:25:04.386 Correction of trade request parameters ...
2019.12.19 04:25:04.386 Pending request created #3:
2019.12.19 04:25:04.386 Pending request to remove a pending order: 
2019.12.19 04:25:04.386 - EURUSD 0.10 Pending order Sell Limit #496816788, Price 1.11829
2019.12.19 04:25:04.386 - Pending request ID: #3, Created 2019.12.18 23:25:01.920, Attempts 5, Wait 00:00:20, End 2019.12.18 23:26:41.920
2019.12.19 04:25:04.386 
2019.12.19 04:25:04.386 CTrading::DeleteOrder: Invalid request:
2019.12.19 04:25:04.386 There is no permission to conduct trading operations in the terminal (the "AutoTrading" button is disabled)
2019.12.19 04:25:04.386 Correction of trade request parameters ...
2019.12.19 04:25:04.387 Pending request created #4:
2019.12.19 04:25:04.387 Pending request to remove a pending order: 
2019.12.19 04:25:04.387 - EURUSD 0.10 Pending order Sell Limit #496816707, Price 1.11784
2019.12.19 04:25:04.387 - Pending request ID: #4, Created 2019.12.18 23:25:01.920, Attempts 5, Wait 00:00:20, End 2019.12.18 23:26:41.920
2019.12.19 04:25:04.387 

如我们所见，EA 已进行了四次尝试，试图删除四笔挂单。 面对终端禁用交易的错误后，它创建了四个延后请求，以及带有其参数的短消息。

然后是等待时间了。
一段时间（20 秒，尽管这取决于报价的到达时间）之后，来自延后请求对象的消息将重复尝试删除这四笔订单，在日志中会显示这些消息：

2019.12.19 04:25:38.780 Retry trading attempt #1:
2019.12.19 04:25:38.780 Pending request to remove a pending order: 
2019.12.19 04:25:38.780 - EURUSD 0.10 Pending order Sell Limit #496816707, Price 1.11784
2019.12.19 04:25:38.780 - Pending request ID: #4, Created 2019.12.18 23:25:01.920, Attempts 5, Wait 00:00:20, End 2019.12.18 23:26:41.920
2019.12.19 04:25:38.780 
2019.12.19 04:25:38.780 Retry trading attempt #1:
2019.12.19 04:25:38.780 Pending request to remove a pending order: 
2019.12.19 04:25:38.780 - EURUSD 0.10 Pending order Buy Limit #497563913, Price 1.11099
2019.12.19 04:25:38.780 - Pending request ID: #2, Created 2019.12.18 23:25:01.920, Attempts 5, Wait 00:00:20, End 2019.12.18 23:26:41.920
2019.12.19 04:25:38.780 
2019.12.19 04:25:38.781 Retry trading attempt #1:
2019.12.19 04:25:38.781 Pending request to remove a pending order: 
2019.12.19 04:25:38.781 - EURUSD 0.10 Pending order Sell Limit #496816788, Price 1.11829
2019.12.19 04:25:38.781 - Pending request ID: #3, Created 2019.12.18 23:25:01.920, Attempts 5, Wait 00:00:20, End 2019.12.18 23:26:41.920
2019.12.19 04:25:38.781 
2019.12.19 04:25:39.103 Retry trading attempt #1:
2019.12.19 04:25:39.103 Pending request to remove a pending order: 
2019.12.19 04:25:39.103 - EURUSD 0.10 Pending order Buy Limit #497568391, Price 1.11076
2019.12.19 04:25:39.103 - Pending request ID: #1, Created 2019.12.18 23:25:01.920, Attempts 5, Wait 00:00:20, End 2019.12.18 23:26:41.920
2019.12.19 04:25:39.103 
2019.12.19 04:25:42.006 Retry trading attempt #2:
2019.12.19 04:25:42.006 Pending request to remove a pending order: 
2019.12.19 04:25:42.006 - EURUSD 0.10 Pending order Buy Limit #497568391, Price 1.11076
2019.12.19 04:25:42.006 - Pending request ID: #1, Created 2019.12.18 23:25:01.920, Attempts 5, Wait 00:00:20, End 2019.12.18 23:26:41.920
2019.12.19 04:25:42.006 
2019.12.19 04:25:42.007 Retry trading attempt #2:
2019.12.19 04:25:42.007 Pending request to remove a pending order: 
2019.12.19 04:25:42.007 - EURUSD 0.10 Pending order Buy Limit #497563913, Price 1.11099
2019.12.19 04:25:42.007 - Pending request ID: #2, Created 2019.12.18 23:25:01.920, Attempts 5, Wait 00:00:20, End 2019.12.18 23:26:41.920
2019.12.19 04:25:42.007 
2019.12.19 04:25:42.007 Retry trading attempt #2:
2019.12.19 04:25:42.007 Pending request to remove a pending order: 
2019.12.19 04:25:42.007 - EURUSD 0.10 Pending order Sell Limit #496816788, Price 1.11829
2019.12.19 04:25:42.007 - Pending request ID: #3, Created 2019.12.18 23:25:01.920, Attempts 5, Wait 00:00:20, End 2019.12.18 23:26:41.920
2019.12.19 04:25:42.007 
2019.12.19 04:25:42.008 Retry trading attempt #2:
2019.12.19 04:25:42.008 Pending request to remove a pending order: 
2019.12.19 04:25:42.008 - EURUSD 0.10 Pending order Sell Limit #496816707, Price 1.11784
2019.12.19 04:25:42.008 - Pending request ID: #4, Created 2019.12.18 23:25:01.920, Attempts 5, Wait 00:00:20, End 2019.12.18 23:26:41.920
2019.12.19 04:25:42.008 
2019.12.19 04:26:03.026 Retry trading attempt #3:
2019.12.19 04:26:03.026 Pending request to remove a pending order: 
2019.12.19 04:26:03.026 - EURUSD 0.10 Pending order Buy Limit #497568391, Price 1.11076
2019.12.19 04:26:03.026 - Pending request ID: #1, Created 2019.12.18 23:25:01.920, Attempts 5, Wait 00:00:20, End 2019.12.18 23:26:41.920
2019.12.19 04:26:03.026 
2019.12.19 04:26:03.027 Retry trading attempt #3:
2019.12.19 04:26:03.027 Pending request to remove a pending order: 
2019.12.19 04:26:03.027 - EURUSD 0.10 Pending order Buy Limit #497563913, Price 1.11099
2019.12.19 04:26:03.027 - Pending request ID: #2, Created 2019.12.18 23:25:01.920, Attempts 5, Wait 00:00:20, End 2019.12.18 23:26:41.920
2019.12.19 04:26:03.027 
2019.12.19 04:26:03.027 Retry trading attempt #3:
2019.12.19 04:26:03.028 Pending request to remove a pending order: 
2019.12.19 04:26:03.028 - EURUSD 0.10 Pending order Sell Limit #496816788, Price 1.11829
2019.12.19 04:26:03.028 - Pending request ID: #3, Created 2019.12.18 23:25:01.920, Attempts 5, Wait 00:00:20, End 2019.12.18 23:26:41.920
2019.12.19 04:26:03.028 
2019.12.19 04:26:03.028 Retry trading attempt #3:
2019.12.19 04:26:03.028 Pending request to remove a pending order: 
2019.12.19 04:26:03.028 - EURUSD 0.10 Pending order Sell Limit #496816707, Price 1.11784
2019.12.19 04:26:03.028 - Pending request ID: #4, Created 2019.12.18 23:25:01.920, Attempts 5, Wait 00:00:20, End 2019.12.18 23:26:41.920
2019.12.19 04:26:03.028 
2019.12.19 04:26:22.357 Retry trading attempt #4:
2019.12.19 04:26:22.357 Pending request to remove a pending order: 
2019.12.19 04:26:22.357 - EURUSD 0.10 Pending order Buy Limit #497568391, Price 1.11076
2019.12.19 04:26:22.357 - Pending request ID: #1, Created 2019.12.18 23:25:01.920, Attempts 5, Wait 00:00:20, End 2019.12.18 23:26:41.920
2019.12.19 04:26:22.357 
2019.12.19 04:26:22.358 Retry trading attempt #4:
2019.12.19 04:26:22.358 Pending request to remove a pending order: 
2019.12.19 04:26:22.358 - EURUSD 0.10 Pending order Buy Limit #497563913, Price 1.11099
2019.12.19 04:26:22.358 - Pending request ID: #2, Created 2019.12.18 23:25:01.920, Attempts 5, Wait 00:00:20, End 2019.12.18 23:26:41.920
2019.12.19 04:26:22.358 
2019.12.19 04:26:22.358 Retry trading attempt #4:
2019.12.19 04:26:22.358 Pending request to remove a pending order: 
2019.12.19 04:26:22.358 - EURUSD 0.10 Pending order Sell Limit #496816788, Price 1.11829
2019.12.19 04:26:22.358 - Pending request ID: #3, Created 2019.12.18 23:25:01.920, Attempts 5, Wait 00:00:20, End 2019.12.18 23:26:41.920
2019.12.19 04:26:22.358 
2019.12.19 04:26:22.359 Retry trading attempt #4:
2019.12.19 04:26:22.359 Pending request to remove a pending order: 
2019.12.19 04:26:22.359 - EURUSD 0.10 Pending order Sell Limit #496816707, Price 1.11784
2019.12.19 04:26:22.359 - Pending request ID: #4, Created 2019.12.18 23:25:01.920, Attempts 5, Wait 00:00:20, End 2019.12.18 23:26:41.920

再次等待下一次交易尝试。 时间到了，由于分配给所有交易尝试的时间期满，故删除延后请求对象：

2019.12.19 04:26:44.004 Pending request ID: #1: Deleted due to expiration
2019.12.19 04:26:44.004 Pending request ID: #2: Deleted due to expiration
2019.12.19 04:26:44.004 Pending request ID: #3: Deleted due to expiration
2019.12.19 04:26:44.004 Pending request ID: #4: Deleted due to expiration

如果分配给所有交易尝试的时间内单击“自动交易”按钮，则延后请求对象将向服务器发送命令以删除挂单，并将自身删除。

以完全相同的方式，我验证了平仓/开仓、下挂单、修改持仓止价单和挂单参数、以及以逆向方式平仓的延后交易请求对象。 事实证明，延后交易请求在大多数情况下都能正常工作。 不过，如果我们先尝试修改挂单，然后再次修改，则这种尝试将失败。 依据同一票据进行两次或更多次交易操作也是如此。 延后请求会于创建后，立即以 “Executed（已执行）” 为原由被删除。 在先前的文章中，在交易类计时器中仅按票据检查延后请求的有效性。 该检查方法在帐户历史记录中检测特定票据刚刚执行的操作。 相应地，系统假定一切正常，是时候删除该请求对象了。 我们稍后会修复它。

下一步是什么？

在下一篇文章中，我们将创建管理延后交易请求的类，并解除无法以相同的订单或持仓连续多次进行相同的交易操作的情况。

返回目录

系列中的前几篇文章：

第一部分 概念，数据管理
第二部分 历史订单和成交集合
第三部分 在场订单和持仓集合，安排搜索
第四部分 交易事件， 概念
第五部分 交易事件类和集合。 将事件发送至程序
第六部分 净持帐户事件
第七部分 StopLimit 挂单激活事件，为订单和持仓修改事件准备功能
第八部分 订单和持仓修改事件
第九部分 与 MQL4 的兼容性 — 准备数据
第十部分 与 MQL4 的兼容性 – 开仓和激活挂单事件
第十一部分 与 MQL4 的兼容性 – 平仓事件
第十二部分 帐户对象类和帐户对象集合
第十三部分 账户对象事件
第十四部分 品种对象
第十五部份 品种对象集合
第十六部分 品种集合事件
第十七部分 函数库对象之间的交互
第十八部分 帐户与任意其他函数库对象的交互
第十九部分 函数库消息类
第二十部分 创建和存储程序资源
第二十一部分 交易类 – 基准跨平台交易对象
第二十二部分 交易类 – 基准交易类，限制验证
第二十三部分 交易类 – 基准交易类，有效参数验证
第二十四部分 交易类 – 基准交易类，无效参数的自动纠正
第二十五部分 交易类 – 基准交易类，处理交易服务器返回的错误
第二十六部分 操控延后交易请求 – 首次实现（开仓）
第二十七部分 操控延后交易请求 – 下挂单
第二十八部分 操控延后交易请求 – 平仓、删除和修改