轻松快捷开发 MetaTrader 程序的函数库(第 二十五部分)：处理交易服务器返回的错误

内容

• 概念
• 实现
• 测试
• 下一步是什么？
  

概念

我们已经实现针对对终端、账户和交易品种的有效参数验证，以及无效交易订单参数的自动校正。 如今只剩下实现发送交易订单后服务器响应的处理了。
将交易订单发送到服务器之后，我们需要检查响应。 服务器返回的错误代码，或未出现错误，都需要我们加以处理。
我们会按照处理无效交易订单参数完全相同的方式执行处理：

• 无错误 — 订单已成功排队等待执行，
  
• 禁用 EA 交易 — 例如，服务器端完全封闭交易操作，
  
• 退出交易方法 — 例如，不可能成功地将订单发送到服务器，持仓已被平仓，或挂单已被删除，
  
• 纠正交易请求参数并重复 — 交易订单参数中存在一些无效值。 很可能在准备服务器请求时已纠正了数据，现在需要进行相应的调整，
  
• 更新数据并重复 — 服务器数据已变化，但无需调整交易请求值，
  
• 等待并重复 — 需要等待，例如，如果价格接近持仓的停止价位之一，则 FreezeLevel 参数将禁止修改，因为停止定单可能已经被激活。 您即可以等待停止订单激活，亦或取消交易请求，再或者等待价格离开冻结区域，以便发送订单到服务器成功，
  
• 创建延后请求 — 在下一篇文章中将会继续讨论。
  

与所实现的修复交易订单中可能的错误相比，返回码数量更多。 此外，并非每个代码都可以被纠正以便重复请求。 为了排除可以修复的错误，我们将尝试处理，并将其发回交易订单。

在发送交易请求的方法中，布置循环来重发交易请求至服务器。 换言之，如果在向服务器发出第一个请求后收到错误，我们会遵循交易类里定义的尝试次数重复发送交易订单 — 直到订单成功发送到服务器，或所有尝试完毕。
如果发送订单到服务器的所有尝试均未成功，则自交易方法返回 false。 在这种情况下，我们能够看到调用程序中的最后一个错误代码。 该代码由交易服务器返回，因此您可以决定如何处理错误。

现在到了动工的时刻了。

实现

打开 Account.mqh 文件，找到 CAccount 帐户类，在帐户对象属性的简化访问部分中， 添加方法，返回工作于对冲类型帐户的标志：

//+------------------------------------------------------------------+
//| Methods of a simplified access to the account object properties  |
//+------------------------------------------------------------------+
//--- Return the account's integer properties
   ENUM_ACCOUNT_TRADE_MODE    TradeMode(void)                        const { return (ENUM_ACCOUNT_TRADE_MODE)this.GetProperty(ACCOUNT_PROP_TRADE_MODE);           }
   ENUM_ACCOUNT_STOPOUT_MODE  MarginSOMode(void)                     const { return (ENUM_ACCOUNT_STOPOUT_MODE)this.GetProperty(ACCOUNT_PROP_MARGIN_SO_MODE);     }
   ENUM_ACCOUNT_MARGIN_MODE   MarginMode(void)                       const { return (ENUM_ACCOUNT_MARGIN_MODE)this.GetProperty(ACCOUNT_PROP_MARGIN_MODE);         }
   long              Login(void)                                     const { return this.GetProperty(ACCOUNT_PROP_LOGIN);                                         }
   long              Leverage(void)                                  const { return this.GetProperty(ACCOUNT_PROP_LEVERAGE);                                      }
   long              LimitOrders(void)                               const { return this.GetProperty(ACCOUNT_PROP_LIMIT_ORDERS);                                  }
   long              TradeAllowed(void)                              const { return this.GetProperty(ACCOUNT_PROP_TRADE_ALLOWED);                                 }
   long              TradeExpert(void)                               const { return this.GetProperty(ACCOUNT_PROP_TRADE_EXPERT);                                  }
   long              CurrencyDigits(void)                            const { return this.GetProperty(ACCOUNT_PROP_CURRENCY_DIGITS);                               }
   long              ServerType(void)                                const { return this.GetProperty(ACCOUNT_PROP_SERVER_TYPE);                                   }
   long              FIFOClose(void)                                 const { return this.GetProperty(ACCOUNT_PROP_FIFO_CLOSE);                                    }
   bool              IsHedge(void)                                   const { return this.MarginMode()==ACCOUNT_MARGIN_MODE_RETAIL_HEDGING;                        }
//--- Return the account's real properties

在 Defines.mqh 文件中，在交易类里添加宏替换，指定默认交易尝试次数。
在本文中，我们将着手创建延后请求，因此我们需要为交易类准备计时器。
所以，我们立即编写交易类的计时器参数：

//+------------------------------------------------------------------+
//| Macro substitutions                                              |
//+------------------------------------------------------------------+
//--- Describe the function with the error line number
#define DFUN_ERR_LINE                  (__FUNCTION__+(TerminalInfoString(TERMINAL_LANGUAGE)=="Russian" ? ", Page " : ", Line ")+(string)__LINE__+": ")
#define DFUN                           (__FUNCTION__+": ")        // "Function description"
#define COUNTRY_LANG                   ("Russian")                // Country language
#define END_TIME                       (D'31.12.3000 23:59:59')   // End date for account history data requests
#define TIMER_FREQUENCY                (16)                       // Minimal frequency of the library timer in milliseconds
#define TOTAL_TRY                      (5)                        // Default number of trading attempts
//--- Standard sounds
#define SND_ALERT                      "alert.wav"
#define SND_ALERT2                     "alert2.wav"
#define SND_CONNECT                    "connect.wav"
#define SND_DISCONNECT                 "disconnect.wav"
#define SND_EMAIL                      "email.wav"
#define SND_EXPERT                     "expert.wav"
#define SND_NEWS                       "news.wav"
#define SND_OK                         "ok.wav"
#define SND_REQUEST                    "request.wav"
#define SND_STOPS                      "stops.wav"
#define SND_TICK                       "tick.wav"
#define SND_TIMEOUT                    "timeout.wav"
#define SND_WAIT                       "wait.wav"
//--- Parameters of the orders and deals collection timer
#define COLLECTION_ORD_PAUSE           (250)                      // Orders and deals collection timer pause in milliseconds
#define COLLECTION_ORD_COUNTER_STEP    (16)                       // Increment of the orders and deals collection timer counter
#define COLLECTION_ORD_COUNTER_ID      (1)                        // Orders and deals collection timer counter ID
//--- Parameters of the account collection timer
#define COLLECTION_ACC_PAUSE           (1000)                     // Account collection timer pause in milliseconds
#define COLLECTION_ACC_COUNTER_STEP    (16)                       // Account timer counter increment
#define COLLECTION_ACC_COUNTER_ID      (2)                        // Account timer counter ID
//--- Symbol collection timer 1 parameters
#define COLLECTION_SYM_PAUSE1          (100)                      // Pause of the symbol collection timer 1 in milliseconds (for scanning market watch symbols)
#define COLLECTION_SYM_COUNTER_STEP1   (16)                       // Increment of the symbol timer 1 counter
#define COLLECTION_SYM_COUNTER_ID1     (3)                        // Symbol timer 1 counter ID
//--- Symbol collection timer 2 parameters
#define COLLECTION_SYM_PAUSE2          (300)                      // Pause of the symbol collection timer 2 in milliseconds (for events of the market watch symbol list)
#define COLLECTION_SYM_COUNTER_STEP2   (16)                       // Increment of the symbol timer 2 counter
#define COLLECTION_SYM_COUNTER_ID2     (4)                        // Symbol timer 2 counter ID
//--- Trading class timer parameters    
#define COLLECTION_REQ_PAUSE           (300)                      // Trading class timer pause in milliseconds
#define COLLECTION_REQ_COUNTER_STEP    (16)                       // Trading class timer counter increment
#define COLLECTION_REQ_COUNTER_ID      (5)                        // Trading class timer counter ID
//--- Collection list IDs
#define COLLECTION_HISTORY_ID          (0x7779)                   // Historical collection list ID
#define COLLECTION_MARKET_ID           (0x777A)                   // Market collection list ID
#define COLLECTION_EVENTS_ID           (0x777B)                   // Event collection list ID
#define COLLECTION_ACCOUNT_ID          (0x777C)                   // Account collection list ID
#define COLLECTION_SYMBOLS_ID          (0x777D)                   // Symbol collection list ID
//--- Data parameters for file operations
#define DIRECTORY                      ("DoEasy\\")               // Library directory for storing object folders
#define RESOURCE_DIR                   ("DoEasy\\Resource\\")     // Library directory for storing resource folders
//--- Symbol parameters
#define CLR_DEFAULT                    (0xFF000000)               // Default color
#define SYMBOLS_COMMON_TOTAL           (1000)                     // Total number of working symbols
//+------------------------------------------------------------------+

在交易服务器错误处理方法的标志列表中添加两个标志 — 挂单价格错误和 stop limit 挂单价格错误的标志。 还有，将纠正交易订单参数的方法添加到处理交易服务器返回码和错误的方法当中：

//+------------------------------------------------------------------+
//| Flags indicating the trading request error handling methods      |
//+------------------------------------------------------------------+
enum ENUM_TRADE_REQUEST_ERR_FLAGS
  {
   TRADE_REQUEST_ERR_FLAG_NO_ERROR                 =  0,    // No error
   TRADE_REQUEST_ERR_FLAG_FATAL_ERROR              =  1,    // Disable trading for an EA (critical error) - exit
   TRADE_REQUEST_ERR_FLAG_INTERNAL_ERR             =  2,    // Library internal error - exit
   TRADE_REQUEST_ERR_FLAG_ERROR_IN_LIST            =  4,    // Error in the list - handle (ENUM_ERROR_CODE_PROCESSING_METHOD)
   TRADE_REQUEST_ERR_FLAG_PRICE_ERROR              =  8,    // Placement price error
   TRADE_REQUEST_ERR_FLAG_LIMIT_ERROR              =  16,   // Limit order price error
  };
//+------------------------------------------------------------------+
//| The methods of handling errors and server return codes           |
//+------------------------------------------------------------------+
enum ENUM_ERROR_CODE_PROCESSING_METHOD
  {
   ERROR_CODE_PROCESSING_METHOD_OK,                         // No errors
   ERROR_CODE_PROCESSING_METHOD_DISABLE,                    // Disable trading for the EA
   ERROR_CODE_PROCESSING_METHOD_EXIT,                       // Exit the trading method
   ERROR_CODE_PROCESSING_METHOD_CORRECT,                    // Correct trading request parameters and repeat
   ERROR_CODE_PROCESSING_METHOD_REFRESH,                    // Update data and repeat
   ERROR_CODE_PROCESSING_METHOD_PENDING,                    // Create a pending request
   ERROR_CODE_PROCESSING_METHOD_WAIT,                       // Wait and repeat
  };
//+------------------------------------------------------------------+

在 Datas.mqh 文件中写入新的消息索引：

//--- CTrading
   MSG_LIB_TEXT_TERMINAL_NOT_TRADE_ENABLED,           // Trade operations are not allowed in the terminal (the AutoTrading button is disabled)
   MSG_LIB_TEXT_EA_NOT_TRADE_ENABLED,                 // EA is not allowed to trade (F7 --> Common --> Allow Automated Trading)
   MSG_LIB_TEXT_ACCOUNT_NOT_TRADE_ENABLED,            // Trading is disabled for the current account
   MSG_LIB_TEXT_ACCOUNT_EA_NOT_TRADE_ENABLED,         // Trading on the trading server side is disabled for EAs on the current account
   MSG_LIB_TEXT_REQUEST_REJECTED_DUE,                 // Request was rejected before sending to the server due to:
   MSG_LIB_TEXT_INVALID_REQUEST,                      // Invalid request:
   MSG_LIB_TEXT_NOT_ENOUTH_MONEY_FOR,                 // Insufficient funds for performing a trade
   MSG_LIB_TEXT_MAX_VOLUME_LIMIT_EXCEEDED,            // Exceeded maximum allowed aggregate volume of orders and positions in one direction
   MSG_LIB_TEXT_REQ_VOL_LESS_MIN_VOLUME,              // Request volume is less than the minimum acceptable one
   MSG_LIB_TEXT_REQ_VOL_MORE_MAX_VOLUME,              // Request volume exceeds the maximum acceptable one
   MSG_LIB_TEXT_CLOSE_BY_ORDERS_DISABLED,             // Close by is disabled
   MSG_LIB_TEXT_INVALID_VOLUME_STEP,                  // Request volume is not a multiple of the minimum lot change step gradation
   MSG_LIB_TEXT_CLOSE_BY_SYMBOLS_UNEQUAL,             // Symbols of opposite positions are not equal
   MSG_LIB_TEXT_SL_LESS_STOP_LEVEL,                   // StopLoss violates requirements for symbol's StopLevel
   MSG_LIB_TEXT_TP_LESS_STOP_LEVEL,                   // TakeProfit violates requirements for symbol's StopLevel
   MSG_LIB_TEXT_PRICE_LESS_STOP_LEVEL,                // Order distance in points is less than a value allowed by symbol's StopLevel parameter
   MSG_LIB_TEXT_LIMIT_LESS_STOP_LEVEL,                // Limit order distance in points relative to a stop order is less than a value allowed by symbol's StopLevel parameter
   MSG_LIB_TEXT_SL_LESS_FREEZE_LEVEL,                 // The distance from the price to StopLoss is less than a value allowed by symbol's FreezeLevel parameter
   MSG_LIB_TEXT_TP_LESS_FREEZE_LEVEL,                 // The distance from the price to TakeProfit is less than a value allowed by symbol's FreezeLevel parameter
   MSG_LIB_TEXT_PR_LESS_FREEZE_LEVEL,                 // The distance from the price to an order activation level is less than a value allowed by symbol's FreezeLevel parameter
   MSG_LIB_TEXT_UNSUPPORTED_SL_TYPE,                  // Unsupported StopLoss parameter type (should be 'int' or 'double')
   MSG_LIB_TEXT_UNSUPPORTED_TP_TYPE,                  // Unsupported TakeProfit parameter type (should be 'int' or 'double')
   MSG_LIB_TEXT_UNSUPPORTED_PR_TYPE,                  // Unsupported price parameter type (should be 'int' or 'double')
   MSG_LIB_TEXT_UNSUPPORTED_PL_TYPE,                  // Unsupported limit order price parameter type (should be 'int' or 'double')
   MSG_LIB_TEXT_UNSUPPORTED_PRICE_TYPE_IN_REQ,        // Unsupported price parameter type in a request
   MSG_LIB_TEXT_TRADING_DISABLE,                      // Trading disabled for the EA until the reason is eliminated
   MSG_LIB_TEXT_TRADING_OPERATION_ABORTED,            // Trading operation is interrupted
   MSG_LIB_TEXT_CORRECTED_TRADE_REQUEST,              // Correcting trading request parameters
   MSG_LIB_TEXT_CREATE_PENDING_REQUEST,               // Creating a pending request
   MSG_LIB_TEXT_NOT_POSSIBILITY_CORRECT_LOT,          // Unable to correct a lot
   MSG_LIB_TEXT_FAILING_CREATE_PENDING_REQ,           // Failed to create a pending request
   MSG_LIB_TEXT_TRY_N,                                // Trading attempt #
   
  };

和消息文本:

   {"Дистанция установки ордера в пунктах меньше разрешённой параметром StopLevel символа","Distance to place order in points less than allowed by symbol's StopLevel"},
   {"Дистанция установки лимит-ордера относительно стоп-ордера меньше разрешённой параметром StopLevel символа","Distance to place limit order relative to stop order less than allowed by symbol's StopLevel"},
   {"Дистанция от цены до StopLoss меньше разрешённой параметром FreezeLevel символа","Distance from price to StopLoss less than allowed by symbol's FreezeLevel"},
   {"Дистанция от цены до TakeProfit меньше разрешённой параметром FreezeLevel символа","Distance from price to TakeProfit less than allowed by symbol's FreezeLevel"},
   {"Дистанция от цены до цены срабатывания ордера меньше разрешённой параметром FreezeLevel символа","Distance from price to order triggering price less than allowed by symbol's FreezeLevel"},
   {"Неподдерживаемый тип параметра StopLoss (необходимо int или double)","Unsupported StopLoss parameter type (int or double required)"},
   {"Неподдерживаемый тип параметра TakeProfit (необходимо int или double)","Unsupported TakeProfit parameter type (int or double required)"},
   {"Неподдерживаемый тип параметра цены (необходимо int или double)","Unsupported price parameter type (int or double required)"},
   {"Неподдерживаемый тип параметра цены limit-ордера (необходимо int или double)","Unsupported type of price parameter for limit order (int or double required)"},
   {"Неподдерживаемый тип параметра цены в запросе","Unsupported price parameter type in request"},
   {"Торговля отключена для эксперта до устранения причины запрета","Trading for expert disabled till this ban eliminated"},
   {"Торговая операция прервана","Trading operation aborted"},
   {"Корректировка параметров торгового запроса ...","Correction of trade request parameters ..."},
   {"Создание отложенного запроса","Create pending request"},
   {"Нет возможности скорректировать лот","Unable to correct lot"},
   {"Не удалось создать отложенный запрос","Failed to create pending request"},
   {"Торговая попытка #","Trading attempt #"},
   
  };

TradeObj.mqh 基准交易对象文件也略微进行了修改。
用于下挂单的方法含有定义要执行的订单类型参数（在此之前使用了默认值）：

//--- Place an order
   bool                       SetOrder(const ENUM_ORDER_TYPE type,
                                       const double volume,
                                       const double price,
                                       const double sl=0,
                                       const double tp=0,
                                       const double price_stoplimit=0,
                                       const ulong magic=ULONG_MAX,
                                       const string comment=NULL,
                                       const datetime expiration=0,
                                       const ENUM_ORDER_TYPE_TIME type_time=WRONG_VALUE,
                                       const ENUM_ORDER_TYPE_FILLING type_filling=WRONG_VALUE);

现在，如果传递的值超过 -1，则使用传递给方法的值。 否则，采用默认参数值:

//+------------------------------------------------------------------+
//| Set an order                                                     |
//+------------------------------------------------------------------+
bool CTradeObj::SetOrder(const ENUM_ORDER_TYPE type,
                         const double volume,
                         const double price,
                         const double sl=0,
                         const double tp=0,
                         const double price_stoplimit=0,
                         const ulong magic=ULONG_MAX,
                         const string comment=NULL,
                         const datetime expiration=0,
                         const ENUM_ORDER_TYPE_TIME type_time=WRONG_VALUE,
                         const ENUM_ORDER_TYPE_FILLING type_filling=WRONG_VALUE)
  {
   ::ResetLastError();
   //--- If an invalid order type has been passed, write the error code and description, send the message to the journal and return 'false'
   if(type==ORDER_TYPE_BUY || type==ORDER_TYPE_SELL || type==ORDER_TYPE_CLOSE_BY 
      #ifdef __MQL4__ || type==ORDER_TYPE_BUY_STOP_LIMIT || type==ORDER_TYPE_SELL_STOP_LIMIT #endif )
     {
      this.m_result.retcode=MSG_LIB_SYS_INVALID_ORDER_TYPE;
      this.m_result.comment=CMessage::Text(this.m_result.retcode);
      if(this.m_log_level>LOG_LEVEL_NO_MSG)
         ::Print(DFUN,CMessage::Text(MSG_LIB_SYS_INVALID_ORDER_TYPE),OrderTypeDescription(type));
      return false;
     }
   //--- Clear the structures
   ::ZeroMemory(this.m_request);
   ::ZeroMemory(this.m_result);
   //--- Fill in the request structure
   this.m_request.action      =  TRADE_ACTION_PENDING;
   this.m_request.symbol      =  this.m_symbol;
   this.m_request.magic       =  (magic==ULONG_MAX ? this.m_magic : magic);
   this.m_request.volume      =  volume;
   this.m_request.type        =  type;
   this.m_request.stoplimit   =  price_stoplimit;
   this.m_request.price       =  price;
   this.m_request.sl          =  sl;
   this.m_request.tp          =  tp;
   this.m_request.expiration  =  expiration;
   this.m_request.type_time   =  (type_time>WRONG_VALUE ? type_time : this.m_type_time);
   this.m_request.type_filling=  (type_filling>WRONG_VALUE ? type_filling : this.m_type_filling);
   this.m_request.comment     =  (comment==NULL ? this.m_comment : comment);
   //--- Return the result of sending a request to the server
#ifdef __MQL5__
   return(!this.m_async_mode ? ::OrderSend(this.m_request,this.m_result) : ::OrderSendAsync(this.m_request,this.m_result));
#else 
   ::ResetLastError();
   int ticket=::OrderSend(m_request.symbol,m_request.type,m_request.volume,m_request.price,(int)m_request.deviation,m_request.sl,m_request.tp,m_request.comment,(int)m_request.magic,m_request.expiration,clrNONE);
   ::SymbolInfoTick(this.m_symbol,this.m_tick);
   if(ticket!=WRONG_VALUE)
     {
      this.m_result.retcode=::GetLastError();
      this.m_result.ask=this.m_tick.ask;
      this.m_result.bid=this.m_tick.bid;
      this.m_result.order=ticket;
      this.m_result.price=(::OrderSelect(ticket,SELECT_BY_TICKET) ? ::OrderOpenPrice() : this.m_request.price);
      this.m_result.volume=(::OrderSelect(ticket,SELECT_BY_TICKET) ? ::OrderLots() : this.m_request.volume);
      this.m_result.comment=CMessage::Text(this.m_result.retcode);
      return true;
     }
   else
     {
      this.m_result.retcode=::GetLastError();
      this.m_result.ask=this.m_tick.ask;
      this.m_result.bid=this.m_tick.bid;
      this.m_result.comment=CMessage::Text(this.m_result.retcode);
      return false;
     }
#endif 
  }
//+------------------------------------------------------------------+

交易订单中的价格也已纠正。 以前，如果图表基于 “最后价格（Last）”，则交易订单中的价格设置为 “要价（Ask）” 和 “最后价格（Last）”。 现在，无论构造图表的价格如何，始终为 “要价（Ask）“ 和 ”出价（Bid）”。

您可以在下面的文件中找到其他次要的修改。 在此啰嗦没有意义。

在 Trading.mqh 文件里 CTrading 交易类的私密部分，添加延后请求列表和存储交易尝试次数的变量：

//+------------------------------------------------------------------+
//| Trading class                                                    |
//+------------------------------------------------------------------+
class CTrading
  {
private:
   CAccount            *m_account;                       // Pointer to the current account object
   CSymbolsCollection  *m_symbols;                       // Pointer to the symbol collection list
   CMarketCollection   *m_market;                        // Pointer to the list of the collection of market orders and positions
   CHistoryCollection  *m_history;                       // Pointer to the list of the collection of historical orders and deals
   CArrayObj            m_list_request;                  // List of pending requests
   CArrayInt            m_list_errors;                   // Error list
   bool                 m_is_trade_disable;              // Flag disabling trading
   bool                 m_use_sound;                     // The flag of using sounds of the object trading events
   uchar                m_total_try;                     // Number of trading attempts
   ENUM_LOG_LEVEL       m_log_level;                     // Logging level
   MqlTradeRequest      m_request;                       // Trading request prices
   ENUM_TRADE_REQUEST_ERR_FLAGS m_error_reason_flags;    // Flags of error source in a trading method
   ENUM_ERROR_HANDLING_BEHAVIOR m_err_handling_behavior; // Behavior when handling error

在将来，我们将使用交易请求列表来存储延后请求类的对象，而 m_total_try 变量会包含交易尝试的次数，默认值在交易类的构造函数中设置：

//+------------------------------------------------------------------+
//| Constructor                                                      |
//+------------------------------------------------------------------+
CTrading::CTrading()
  {
   this.m_list_errors.Clear();
   this.m_list_errors.Sort();
   this.m_list_request.Clear();
   this.m_list_request.Sort();
   this.m_total_try=TOTAL_TRY;
   this.m_log_level=LOG_LEVEL_ALL_MSG;
   this.m_is_trade_disable=false;
   this.m_err_handling_behavior=ERROR_HANDLING_BEHAVIOR_CORRECT;
   ::ZeroMemory(this.m_request);
  }
//+------------------------------------------------------------------+

此处，清除延后请求的列表，并为其设置列表已排序标志。

将 StopLimit 类型挂单的限价单价格添加至检查价格相对于 StopLevel 的方法参数中：

bool CheckPriceByStopLevel(const ENUM_ORDER_TYPE order_type,const double price,const CSymbol *symbol_obj,const double limit=0);

将检查添加到方法本身：

//+------------------------------------------------------------------+
//| Return the flag checking the validity of the distance            |
//| from the price to the placement level by StopLevel               |
//+------------------------------------------------------------------+
bool CTrading::CheckPriceByStopLevel(const ENUM_ORDER_TYPE order_type,const double price,const CSymbol *symbol_obj,const double limit=0)
  {
   double lv=symbol_obj.TradeStopLevel()*symbol_obj.Point();
   double pr=(this.DirectionByActionType((ENUM_ACTION_TYPE)order_type)==ORDER_TYPE_BUY ? symbol_obj.Ask() : symbol_obj.Bid());
   return
     (limit==0 ?
      //--- Order placement prices relative to the price
      (
       order_type==ORDER_TYPE_SELL_STOP         ||
       order_type==ORDER_TYPE_SELL_STOP_LIMIT   ||
       order_type==ORDER_TYPE_BUY_LIMIT         ?  price<(pr-lv)     :
       order_type==ORDER_TYPE_BUY_STOP          ||
       order_type==ORDER_TYPE_BUY_STOP_LIMIT    ||
       order_type==ORDER_TYPE_SELL_LIMIT        ?  price>(pr+lv)     :
       true
      ) : 
      //--- Limit order placement prices relative to the stop order price
      (
       order_type==ORDER_TYPE_BUY_STOP_LIMIT    ?  limit<(price-lv)  :  
       order_type==ORDER_TYPE_SELL_STOP_LIMIT   ?  limit>(price+lv)  :
      true
      )
     );
  }
//+------------------------------------------------------------------+

此处，如果限价单价格等于零，则检查停止和限价单的价格，否则检查 stop limit 挂单价格（stop limit 单被激活后，相对于停止单的限价单价格）。

将错误代码传递给返回错误处理方式的方法，并在错误纠正方法中添加指向交易对象的指针：

//--- Return the error handling method
   ENUM_ERROR_CODE_PROCESSING_METHOD   ResultProccessingMethod(const uint result_code);
//--- Correct errors
   ENUM_ERROR_CODE_PROCESSING_METHOD   RequestErrorsCorrecting(MqlTradeRequest &request,const ENUM_ORDER_TYPE order_type,const uint spread_multiplier,CSymbol *symbol_obj,CTradeObj *trade_obj);

由于我们有多种开仓和下单的方法，事实证明所有方法几乎都相同。 区别仅在于已开仓位和已下订单的类型。
出于避免为每种方法编写相同的代码，声明并实现两个私密方法 — 开仓和下挂单：

//--- (1) Open a position, (2) place a pending order
   template<typename SL,typename TP> 
   bool                 OpenPosition(const ENUM_POSITION_TYPE type,
                                    const double volume,
                                    const string symbol,
                                    const ulong magic=ULONG_MAX,
                                    const SL sl=0,
                                    const TP tp=0,
                                    const string comment=NULL,
                                    const ulong deviation=ULONG_MAX);
   template<typename PS,typename PL,typename SL,typename TP>
   bool                 PlaceOrder( const ENUM_ORDER_TYPE order_type,
                                    const double volume,
                                    const string symbol,
                                    const PS price_stop,
                                    const PL price_limit=0,
                                    const SL sl=0,
                                    const TP tp=0,
                                    const ulong magic=ULONG_MAX,
                                    const string comment=NULL,
                                    const datetime expiration=0,
                                    const ENUM_ORDER_TYPE_TIME type_time=WRONG_VALUE,
                                    const ENUM_ORDER_TYPE_FILLING type_filling=WRONG_VALUE);
public:
//--- Constructor

在该类的公开部分，我们将需要为处理延后请求类声明计时器，返回延后列表的方法，和 设置交易尝试次数的方法：

public:
//--- Constructor
                        CTrading();
//--- Timer
   void                 OnTimer(void);
//--- Get the pointers to the lists (make sure to call the method in program's OnInit() since the symbol collection list is created there)
   void                 OnInit(CAccount *account,CSymbolsCollection *symbols,CMarketCollection *market,CHistoryCollection *history)
                          {
                           this.m_account=account;
                           this.m_symbols=symbols;
                           this.m_market=market;
                           this.m_history=history;
                          }
//--- Return the list of (1) errors and (2) pending requests
   CArrayInt           *GetListErrors(void)                             { return &this.m_list_errors; }
   CArrayObj           *GetListRequests(void)                           { return &this.m_list_request;}
//--- Set the number of trading attempts
   void                 SetTotalTry(const uchar number)                 { this.m_total_try=number;    }
//--- Check limitations and errors

我们改进按平仓量平仓的方法规范。 默认值为 WRONG_VALUE — 完全平仓，否则 — 按指定交易量部分平仓：

bool ClosePosition(const ulong ticket,const double volume=WRONG_VALUE,const string comment=NULL,const ulong deviation=ULONG_MAX);

在挂单处理方法的规范中，添加执行订单超量的类型。 以前，采用的是为该类设置的默认值。 现在，基于传递给方法的值选择订单执行类型值。 如果是 WRONG_VALUE，则默认设置为指定值，否则将采用传递给该方法的值：

//--- Set (1) BuyStop, (2) BuyLimit, (3) BuyStopLimit pending order
   template<typename PS,typename SL,typename TP>
   bool                 PlaceBuyStop(const double volume,
                                           const string symbol,
                                           const PS price,
                                           const SL sl=0,
                                           const TP tp=0,
                                           const ulong magic=ULONG_MAX,
                                           const string comment=NULL,
                                           const datetime expiration=0,
                                           const ENUM_ORDER_TYPE_TIME type_time=WRONG_VALUE,
                                           const ENUM_ORDER_TYPE_FILLING type_filling=WRONG_VALUE);
   template<typename PS,typename SL,typename TP>
   bool                 PlaceBuyLimit(const double volume,
                                           const string symbol,
                                           const PS price,
                                           const SL sl=0,
                                           const TP tp=0,
                                           const ulong magic=ULONG_MAX,
                                           const string comment=NULL,
                                           const datetime expiration=0,
                                           const ENUM_ORDER_TYPE_TIME type_time=WRONG_VALUE,
                                           const ENUM_ORDER_TYPE_FILLING type_filling=WRONG_VALUE);
   template<typename PS,typename PL,typename SL,typename TP>
   bool                 PlaceBuyStopLimit(const double volume,
                                           const string symbol,
                                           const PS price_stop,
                                           const PL price_limit,
                                           const SL sl=0,
                                           const TP tp=0,
                                           const ulong magic=ULONG_MAX,
                                           const string comment=NULL,
                                           const datetime expiration=0,
                                           const ENUM_ORDER_TYPE_TIME type_time=WRONG_VALUE,
                                           const ENUM_ORDER_TYPE_FILLING type_filling=WRONG_VALUE);

//--- Set (1) SellStop, (2) SellLimit, (3) SellStopLimit pending order
   template<typename PS,typename SL,typename TP>
   bool                 PlaceSellStop(const double volume,
                                           const string symbol,
                                           const PS price,
                                           const SL sl=0,
                                           const TP tp=0,
                                           const ulong magic=ULONG_MAX,
                                           const string comment=NULL,
                                           const datetime expiration=0,
                                           const ENUM_ORDER_TYPE_TIME type_time=WRONG_VALUE,
                                           const ENUM_ORDER_TYPE_FILLING type_filling=WRONG_VALUE);
   template<typename PS,typename SL,typename TP>
   bool                 PlaceSellLimit(const double volume,
                                           const string symbol,
                                           const PS price,
                                           const SL sl=0,
                                           const TP tp=0,
                                           const ulong magic=ULONG_MAX,
                                           const string comment=NULL,
                                           const datetime expiration=0,
                                           const ENUM_ORDER_TYPE_TIME type_time=WRONG_VALUE,
                                           const ENUM_ORDER_TYPE_FILLING type_filling=WRONG_VALUE);
   template<typename PS,typename PL,typename SL,typename TP>
   bool                 PlaceSellStopLimit(const double volume,
                                           const string symbol,
                                           const PS price_stop,
                                           const PL price_limit,
                                           const SL sl=0,
                                           const TP tp=0,
                                           const ulong magic=ULONG_MAX,
                                           const string comment=NULL,
                                           const datetime expiration=0,
                                           const ENUM_ORDER_TYPE_TIME type_time=WRONG_VALUE,
                                           const ENUM_ORDER_TYPE_FILLING type_filling=WRONG_VALUE);
//--- Modify a pending order
   template<typename PS,typename PL,typename SL,typename TP>
   bool                 ModifyOrder(const ulong ticket,
                                          const PS price=WRONG_VALUE,
                                          const SL sl=WRONG_VALUE,
                                          const TP tp=WRONG_VALUE,
                                          const PL limit=WRONG_VALUE,
                                          datetime expiration=WRONG_VALUE,
                                          const ENUM_ORDER_TYPE_TIME type_time=WRONG_VALUE,
                                          const ENUM_ORDER_TYPE_FILLING type_filling=WRONG_VALUE);

我们实现计时器 。 到目前为止，我们将准备一个处理延后请求列表的工件：

//+------------------------------------------------------------------+
//| Timer                                                            |
//+------------------------------------------------------------------+
void CTrading::OnTimer(void)
  {
   int total=this.m_list_request.Total();
   for(int i=total-1;i>WRONG_VALUE;i--)
     {
      
     }
  }
//+------------------------------------------------------------------+

实现依据交易服务器返回代码返回处理方式的方法：

//+------------------------------------------------------------------+
//| Return the error handling method                                 |
//+------------------------------------------------------------------+
ENUM_ERROR_CODE_PROCESSING_METHOD CTrading::ResultProccessingMethod(const uint result_code)
  {
   switch(result_code)
     {
   #ifdef __MQL4__
      //--- Malfunctional trade operation
      case 9   :
      //--- Account disabled
      case 64  :
      //--- Invalid account number
      case 65  :  return ERROR_CODE_PROCESSING_METHOD_DISABLE;
      
      //--- No error but result is unknown
      case 1   :
      //--- General error
      case 2   :
      //--- Old client terminal version
      case 5   :
      //--- Not enough rights
      case 7   :
      //--- Market closed
      case 132 :
      //--- Trading disabled
      case 133 :
      //--- Order is locked and being processed
      case 139 :
      //--- Buy only
      case 140 :
      //--- The number of open and pending orders has reached the limit set by the broker
      case 148 :
      //--- Attempt to open an opposite order if hedging is disabled
      case 149 :
      //--- Attempt to close a position on a symbol contradicts the FIFO rule
      case 150 :  return ERROR_CODE_PROCESSING_METHOD_EXIT;
      
      //--- Invalid trading request parameters
      case 3   :
      //--- Invalid price
      case 129 :
      //--- Invalid stop levels
      case 130 :
      //--- Invalid volume
      case 131 :
      //--- Not enough money to perform the operation
      case 134 :
      //--- Expirations are denied by broker
      case 147 :  return ERROR_CODE_PROCESSING_METHOD_CORRECT;
      
      //--- Trade server is busy
      case 4   :  return (ENUM_ERROR_CODE_PROCESSING_METHOD)5000;    // ERROR_CODE_PROCESSING_METHOD_WAIT
      //--- No connection to the trade server
      case 6   :  return (ENUM_ERROR_CODE_PROCESSING_METHOD)5000;    // ERROR_CODE_PROCESSING_METHOD_WAIT
      //--- Too frequent requests
      case 8   :  return (ENUM_ERROR_CODE_PROCESSING_METHOD)10000;   // ERROR_CODE_PROCESSING_METHOD_WAIT
      //--- No price
      case 136 :  return (ENUM_ERROR_CODE_PROCESSING_METHOD)5000;    // ERROR_CODE_PROCESSING_METHOD_WAIT
      //--- Broker is busy
      case 137 :  return (ENUM_ERROR_CODE_PROCESSING_METHOD)5000;    // ERROR_CODE_PROCESSING_METHOD_WAIT
      //--- Too many requests
      case 141 :  return (ENUM_ERROR_CODE_PROCESSING_METHOD)10000;   // ERROR_CODE_PROCESSING_METHOD_WAIT
      //--- Modification denied because the order is too close to market
      case 145 :  return (ENUM_ERROR_CODE_PROCESSING_METHOD)5000;    // ERROR_CODE_PROCESSING_METHOD_WAIT
      //--- Trade context is busy
      case 146 :  return (ENUM_ERROR_CODE_PROCESSING_METHOD)1000;    // ERROR_CODE_PROCESSING_METHOD_WAIT
      
      //--- Trade timeout
      case 128 :
      //--- Price has changed
      case 135 :
      //--- New prices
      case 138 :  return ERROR_CODE_PROCESSING_METHOD_REFRESH;

   //--- MQL5
   #else 
      //--- Auto trading disabled by the server
      case 10026  :  return ERROR_CODE_PROCESSING_METHOD_DISABLE;
      
      //--- Request canceled by a trader
      case 10007  :
      //--- Request expired
      case 10012  :
      //--- Trading disabled
      case 10017 :
      //--- Market closed
      case 10018  :
      //--- Order status changed
      case 10023  :
      //--- Request unchanged
      case 10025  :
      //--- Request blocked for handling
      case 10028  :
      //--- Transaction is allowed for live accounts only
      case 10032  :
      //--- The maximum number of pending orders is reached
      case 10033  :
      //--- Reached the maximum order and position volume for this symbol
      case 10034  :
      //--- Invalid or prohibited order type
      case 10035  :
      //--- Position with the specified ID already closed
      case 10036  :
      //--- A close order is already present for a specified position
      case 10039  :
      //--- The maximum number of open positions is reached
      case 10040  :
      //--- Request to activate a pending order is rejected, the order is canceled
      case 10041  :
      //--- Request is rejected, because the rule "Only long positions are allowed" is set for the symbol
      case 10042  :
      //--- Request is rejected, because the rule "Only short positions are allowed" is set for the symbol
      case 10043  :
      //--- Request is rejected, because the rule "Only closing of existing positions is allowed" is set for the symbol
      case 10044  :
      //--- Request is rejected, because the rule "Only closing of existing positions by FIFO rule is allowed" is set for the symbol
      case 10045  :  return ERROR_CODE_PROCESSING_METHOD_EXIT;

      //--- Requote
      case 10004  :
      //--- Request rejected
      case 10006  :
      //--- Prices changed
      case 10020  :  return ERROR_CODE_PROCESSING_METHOD_REFRESH;

      //--- Invalid request
      case 10013  :
      //--- Invalid request volume
      case 10014  :
      //--- Invalid request price
      case 10015  :
      //--- Invalid request stop levels
      case 10016  :
      //--- Insufficient funds for request execution
      case 10019  :
      //--- Invalid order expiration in a request
      case 10022  :
      //--- The specified type of order execution by balance is not supported
      case 10030  :
      //--- Closed volume exceeds the current position volume
      case 10038  :  return ERROR_CODE_PROCESSING_METHOD_CORRECT;

      //--- No quotes to process the request
      case 10021  :  return (ENUM_ERROR_CODE_PROCESSING_METHOD)5000;    // ERROR_CODE_PROCESSING_METHOD_WAIT;
      //--- Too frequent requests
      case 10024  :  return (ENUM_ERROR_CODE_PROCESSING_METHOD)10000;   // ERROR_CODE_PROCESSING_METHOD_WAIT
      //--- An order or a position is frozen
      case 10029  :  return (ENUM_ERROR_CODE_PROCESSING_METHOD)10000;   // ERROR_CODE_PROCESSING_METHOD_WAIT;

      //--- Request handling error
      case 10011  :  return ERROR_CODE_PROCESSING_METHOD_PENDING;
      //--- Auto trading disabled by the client terminal
      case 10027  :  return ERROR_CODE_PROCESSING_METHOD_PENDING;
      //--- No connection to the trade server
      case 10031  :  return ERROR_CODE_PROCESSING_METHOD_PENDING;

      //--- Order placed
      case 10008  :
      //--- Request executed
      case 10009  :
      //--- Request executed partially
      case 10010  :
   #endif 
      //--- "OK"
      default:
        break;
     }
   return ERROR_CODE_PROCESSING_METHOD_OK;
  }
//+------------------------------------------------------------------+

此处一切都很简单：发送交易请求至服务器后，方法接收从服务器获取的代码。 然后，这些代码示意该错误的可修复方法，相应的更新数据和重新发送请求的代码，等等。
由于 MQL5 和 MQL4 服务器返回不同的错误代码，因此该方法提供了针对 MQL4 和 MQL5 的条件编译功能。
所有需要相同处理类型的代码都被分组到 switch 运算符的单个 case 中，并依据交易服务器返回码返回统一的处理方法。

实现交易服务器错误的处理方法：

//+------------------------------------------------------------------+
//| Correct errors                                                   |
//+------------------------------------------------------------------+
ENUM_ERROR_CODE_PROCESSING_METHOD CTrading::RequestErrorsCorrecting(MqlTradeRequest &request,
                                                                    const ENUM_ORDER_TYPE order_type,
                                                                    const uint spread_multiplier,
                                                                    CSymbol *symbol_obj,
                                                                    CTradeObj *trade_obj)
  {
//--- The empty error list means no errors are detected, return success
   int total=this.m_list_errors.Total();
   if(total==0)
      return ERROR_CODE_PROCESSING_METHOD_OK;

//--- Trading is disabled for the current account
//--- write the error code to the base trading class object and return "exit from the trading method"
   if(this.IsPresentErorCode(MSG_LIB_TEXT_ACCOUNT_NOT_TRADE_ENABLED))
     {
      trade_obj.SetResultRetcode(MSG_LIB_TEXT_ACCOUNT_NOT_TRADE_ENABLED);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      return ERROR_CODE_PROCESSING_METHOD_EXIT;
     }
//--- Trading on the trading server side is disabled for EAs on the current account
//--- write the error code to the base trading class object and return "exit from the trading method"
   if(this.IsPresentErorCode(MSG_LIB_TEXT_ACCOUNT_EA_NOT_TRADE_ENABLED))
     {
      trade_obj.SetResultRetcode(MSG_LIB_TEXT_ACCOUNT_EA_NOT_TRADE_ENABLED);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      return ERROR_CODE_PROCESSING_METHOD_EXIT;
     }
//--- Trading operations are disabled in the terminal
//--- write the error code to the base trading class object and return "exit from the trading method"
   if(this.IsPresentErorCode(MSG_LIB_TEXT_TERMINAL_NOT_TRADE_ENABLED))
     {
      trade_obj.SetResultRetcode(MSG_LIB_TEXT_TERMINAL_NOT_TRADE_ENABLED);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      return ERROR_CODE_PROCESSING_METHOD_EXIT;
     }
//--- Trading operations are disabled for the EA
//--- write the error code to the base trading class object and return "exit from the trading method"
   if(this.IsPresentErorCode(MSG_LIB_TEXT_EA_NOT_TRADE_ENABLED))
     {
      trade_obj.SetResultRetcode(MSG_LIB_TEXT_EA_NOT_TRADE_ENABLED);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      return ERROR_CODE_PROCESSING_METHOD_EXIT;
     }
//--- Disable trading on a symbol
//--- write the error code to the base trading class object and return "exit from the trading method"
   if(this.IsPresentErorCode(MSG_SYM_TRADE_MODE_DISABLED))
     {
      trade_obj.SetResultRetcode(MSG_SYM_TRADE_MODE_DISABLED);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      return ERROR_CODE_PROCESSING_METHOD_EXIT;
     }
//--- Close only
//--- write the error code to the base trading class object and return "exit from the trading method"
   if(this.IsPresentErorCode(MSG_SYM_TRADE_MODE_CLOSEONLY))
     {
      trade_obj.SetResultRetcode(MSG_SYM_TRADE_MODE_CLOSEONLY);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      return ERROR_CODE_PROCESSING_METHOD_EXIT;
     }
//--- Market orders are disabled
//--- write the error code to the base trading class object and return "exit from the trading method"
   if(this.IsPresentErorCode(MSG_SYM_MARKET_ORDER_DISABLED))
     {
      trade_obj.SetResultRetcode(MSG_SYM_MARKET_ORDER_DISABLED);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      return ERROR_CODE_PROCESSING_METHOD_EXIT;
     }
//--- Limit orders are disabled
//--- write the error code to the base trading class object and return "exit from the trading method"
   if(this.IsPresentErorCode(MSG_SYM_LIMIT_ORDER_DISABLED))
     {
      trade_obj.SetResultRetcode(MSG_SYM_LIMIT_ORDER_DISABLED);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      return ERROR_CODE_PROCESSING_METHOD_EXIT;
     }
//--- Stop orders are disabled
//--- write the error code to the base trading class object and return "exit from the trading method"
   if(this.IsPresentErorCode(MSG_SYM_STOP_ORDER_DISABLED))
     {
      trade_obj.SetResultRetcode(MSG_SYM_STOP_ORDER_DISABLED);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      return ERROR_CODE_PROCESSING_METHOD_EXIT;
     }
//--- StopLimit orders are disabled
//--- write the error code to the base trading class object and return "exit from the trading method"
   if(this.IsPresentErorCode(MSG_SYM_STOP_LIMIT_ORDER_DISABLED))
     {
      trade_obj.SetResultRetcode(MSG_SYM_STOP_LIMIT_ORDER_DISABLED);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      return ERROR_CODE_PROCESSING_METHOD_EXIT;
     }
//--- Sell only
//--- write the error code to the base trading class object and return "exit from the trading method"
   if(this.IsPresentErorCode(MSG_SYM_TRADE_MODE_SHORTONLY))
     {
      trade_obj.SetResultRetcode(MSG_SYM_TRADE_MODE_SHORTONLY);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      return ERROR_CODE_PROCESSING_METHOD_EXIT;
     }
//--- Buy only
//--- write the error code to the base trading class object and return "exit from the trading method"
   if(this.IsPresentErorCode(MSG_SYM_TRADE_MODE_LONGONLY))
     {
      trade_obj.SetResultRetcode(MSG_SYM_TRADE_MODE_LONGONLY);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      return ERROR_CODE_PROCESSING_METHOD_EXIT;
     }
//--- CloseBy orders are disabled
//--- write the error code to the base trading class object and return "exit from the trading method"
   if(this.IsPresentErorCode(MSG_SYM_CLOSE_BY_ORDER_DISABLED))
     {
      trade_obj.SetResultRetcode(MSG_SYM_CLOSE_BY_ORDER_DISABLED);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      return ERROR_CODE_PROCESSING_METHOD_EXIT;
     }
//--- Exceeded maximum allowed aggregate volume of orders and positions in one direction
//--- write the error code to the base trading class object and return "exit from the trading method"
   if(this.IsPresentErorCode(MSG_LIB_TEXT_MAX_VOLUME_LIMIT_EXCEEDED))
     {
      trade_obj.SetResultRetcode(MSG_LIB_TEXT_MAX_VOLUME_LIMIT_EXCEEDED);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      return ERROR_CODE_PROCESSING_METHOD_EXIT;
     }
//--- Close by is disabled
//--- write the error code to the base trading class object and return "exit from the trading method"
   if(this.IsPresentErorCode(MSG_LIB_TEXT_CLOSE_BY_ORDERS_DISABLED))
     {
      trade_obj.SetResultRetcode(MSG_LIB_TEXT_CLOSE_BY_ORDERS_DISABLED);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      return ERROR_CODE_PROCESSING_METHOD_EXIT;
     }
//--- Symbols of opposite positions are not equal
//--- write the error code to the base trading class object and return "exit from the trading method"
   if(this.IsPresentErorCode(MSG_LIB_TEXT_CLOSE_BY_SYMBOLS_UNEQUAL))
     {
      trade_obj.SetResultRetcode(MSG_LIB_TEXT_CLOSE_BY_SYMBOLS_UNEQUAL);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      return ERROR_CODE_PROCESSING_METHOD_EXIT;
     }
//--- Unsupported price parameter type in a request
//--- write the error code to the base trading class object and return "exit from the trading method"
   if(this.IsPresentErorCode(MSG_LIB_TEXT_UNSUPPORTED_PRICE_TYPE_IN_REQ))
     {
      trade_obj.SetResultRetcode(MSG_LIB_TEXT_UNSUPPORTED_PRICE_TYPE_IN_REQ);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      return ERROR_CODE_PROCESSING_METHOD_EXIT;
     }
//--- Trading disabled for the EA until the reason is eliminated
//--- write the error code to the base trading class object and return "exit from the trading method"
   if(this.IsPresentErorCode(MSG_LIB_TEXT_TRADING_DISABLE))
     {
      trade_obj.SetResultRetcode(MSG_LIB_TEXT_TRADING_DISABLE);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      return ERROR_CODE_PROCESSING_METHOD_EXIT;
     }
//--- The maximum number of pending orders is reached
//--- write the error code to the base trading class object and return "exit from the trading method"
   if(this.IsPresentErorCode(10033))
     {
      trade_obj.SetResultRetcode(10033);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      return ERROR_CODE_PROCESSING_METHOD_EXIT;
     }
//--- Reached the maximum order and position volume for this symbol
//--- write the error code to the base trading class object and return "exit from the trading method"
   if(this.IsPresentErorCode(10034))
     {
      trade_obj.SetResultRetcode(10034);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      return ERROR_CODE_PROCESSING_METHOD_EXIT;
     }

//--- Correcting trading request parameters
//--- Price, according to which stop orders are placed
   double price_set=(this.IsPresentErrorFlag(TRADE_REQUEST_ERR_FLAG_PRICE_ERROR) ? request.price : request.stoplimit);
//--- First, adjust stop orders relative to the order/position level
   if(this.IsPresentErorCode(MSG_LIB_TEXT_SL_LESS_STOP_LEVEL))
      request.sl=this.CorrectStopLoss(order_type,price_set,request.sl,symbol_obj,spread_multiplier);
   if(this.IsPresentErorCode(MSG_LIB_TEXT_TP_LESS_STOP_LEVEL))
      request.tp=this.CorrectTakeProfit(order_type,price_set,request.tp,symbol_obj,spread_multiplier);
//--- Pending orders price
   double shift=0;
   if(this.IsPresentErrorFlag(TRADE_REQUEST_ERR_FLAG_PRICE_ERROR))
     {
      price_set=request.price;
      request.price=this.CorrectPricePending(order_type,price_set,0,symbol_obj,spread_multiplier);   
      shift=request.price-price_set; 
      //--- If this is not a stop limit order, move stop orders by the calculated correcting order level shift
      if(request.stoplimit==0)
        {
         if(request.sl>0)
            request.sl=this.CorrectStopLoss(order_type,request.price,request.sl+shift,symbol_obj,spread_multiplier);
         if(request.tp>0)
            request.tp=this.CorrectTakeProfit(order_type,request.price,request.tp+shift,symbol_obj,spread_multiplier);                                                               
        }
     }
//--- The specified type of order execution by balance is not supported
   if(this.IsPresentErorCode(10030))
      request.type_filling=symbol_obj.GetCorrectTypeFilling();
//--- Invalid order expiration in a request -
   if(this.IsPresentErorCode(10022))
     {
      //--- if the expiration type is not supported as set by the expiration date and the expiration data is defined, reset the expiration date
      if(!symbol_obj.IsExpirationModeSpecified() && request.expiration>0)
         request.expiration=0;
     }
//--- View the list of remaining errors and correct trading request parameters
   for(int i=0;i<total;i++)
     {
      int err=this.m_list_errors.At(i);
      if(err==NULL)
         continue;
      switch(err)
        {
         //--- Correct an invalid volume and disabling stop levels in a trading request
         case MSG_LIB_TEXT_REQ_VOL_LESS_MIN_VOLUME :
         case MSG_LIB_TEXT_REQ_VOL_MORE_MAX_VOLUME :
         case MSG_LIB_TEXT_INVALID_VOLUME_STEP     :  request.volume=symbol_obj.NormalizedLot(request.volume);                                              break;
         case MSG_SYM_SL_ORDER_DISABLED            :  request.sl=0;                                                                                         break;
         case MSG_SYM_TP_ORDER_DISABLED            :  request.tp=0;                                                                                         break;
         
         //--- If unable to select the position lot, return "abort trading attempt" since the funds are insufficient even for the minimum lot
         case MSG_LIB_TEXT_NOT_ENOUTH_MONEY_FOR    :  request.volume=this.CorrectVolume(request.price,order_type,symbol_obj,DFUN);
                                                      if(request.volume==0)
                                                        {
                                                         trade_obj.SetResultRetcode(MSG_LIB_TEXT_NOT_POSSIBILITY_CORRECT_LOT);
                                                         trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
                                                         return ERROR_CODE_PROCESSING_METHOD_EXIT;                                                                                      break;
                                                        }
         //--- No quotes to process the request
         case 10021                                :  trade_obj.SetResultRetcode(10021);
                                                      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
                                                      return (ENUM_ERROR_CODE_PROCESSING_METHOD)5000; // ERROR_CODE_PROCESSING_METHOD_WAIT - wait 5 seconds
         //--- No connection to the trade server
         case 10031                                :  trade_obj.SetResultRetcode(10031);
                                                      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
                                                      return (ENUM_ERROR_CODE_PROCESSING_METHOD)5000; // ERROR_CODE_PROCESSING_METHOD_WAIT - wait 5 seconds
                                                      
         //--- Proximity to the order activation level is handled by five-second waiting - during this time, the price may go beyond the freeze level
         case MSG_LIB_TEXT_SL_LESS_FREEZE_LEVEL    :
         case MSG_LIB_TEXT_TP_LESS_FREEZE_LEVEL    :
         case MSG_LIB_TEXT_PR_LESS_FREEZE_LEVEL    :  return (ENUM_ERROR_CODE_PROCESSING_METHOD)5000; // ERROR_CODE_PROCESSING_METHOD_WAIT - wait 5 seconds
         default:
           break;
        }
     }
//--- No errors - return ОК
   trade_obj.SetResultRetcode(0);
   trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
   return ERROR_CODE_PROCESSING_METHOD_OK;
  }
//+------------------------------------------------------------------+

方法清单的代码注释包含处理交易服务器返回错误的所有动作。

实现开仓的私密方法：

//+------------------------------------------------------------------+
//| Open a position                                                  |
//+------------------------------------------------------------------+
template<typename SL,typename TP> 
bool CTrading::OpenPosition(const ENUM_POSITION_TYPE type,
                            const double volume,
                            const string symbol,
                            const ulong magic=ULONG_MAX,
                            const SL sl=0,
                            const TP tp=0,
                            const string comment=NULL,
                            const ulong deviation=ULONG_MAX)
  {
//--- Set the trading request result as 'true' and the error flag as "no errors"
   bool res=true;
   this.m_error_reason_flags=TRADE_REQUEST_ERR_FLAG_NO_ERROR;
   ENUM_ORDER_TYPE order_type=(ENUM_ORDER_TYPE)type;
   ENUM_ACTION_TYPE action=(ENUM_ACTION_TYPE)order_type;
//--- Get a symbol object by a symbol name. If failed to get
   CSymbol *symbol_obj=this.m_symbols.GetSymbolObjByName(symbol);
//--- If failed to get - write the "internal error" flag, display the message in the journal and return 'false'
   if(symbol_obj==NULL)
     {
      this.m_error_reason_flags=TRADE_REQUEST_ERR_FLAG_INTERNAL_ERR;
      if(this.m_log_level>LOG_LEVEL_NO_MSG)
         ::Print(DFUN,CMessage::Text(MSG_LIB_SYS_ERROR_FAILED_GET_SYM_OBJ));
      return false;
     }
//--- get a trading object from a symbol object
   CTradeObj *trade_obj=symbol_obj.GetTradeObj();
//--- If failed to get - write the "internal error" flag, display the message in the journal and return 'false'
   if(trade_obj==NULL)
     {
      this.m_error_reason_flags=TRADE_REQUEST_ERR_FLAG_INTERNAL_ERR;
      if(this.m_log_level>LOG_LEVEL_NO_MSG)
         ::Print(DFUN,CMessage::Text(MSG_LIB_SYS_ERROR_FAILED_GET_TRADE_OBJ));
      return false;
     }
//--- Set the prices
//--- If failed to set - write the "internal error" flag, set the error code in the return structure,
//--- display the message in the journal and return 'false'
   if(!this.SetPrices(order_type,0,sl,tp,0,DFUN,symbol_obj))
     {
      this.m_error_reason_flags=TRADE_REQUEST_ERR_FLAG_INTERNAL_ERR;
      trade_obj.SetResultRetcode(10021);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      if(this.m_log_level>LOG_LEVEL_NO_MSG)
         ::Print(DFUN,CMessage::Text(10021));   // No quotes to process the request
      return false;
     }

//--- Write the volume to the request structure
   this.m_request.volume=volume;
//--- Get the method of handling errors from the CheckErrors() method while checking for errors in the request parameters
   ENUM_ERROR_CODE_PROCESSING_METHOD method=this.CheckErrors(this.m_request.volume,symbol_obj.Ask(),action,order_type,symbol_obj,trade_obj,DFUN,0,this.m_request.sl,this.m_request.tp);
//--- In case of trading limitations, funds insufficiency,
//--- if there are limitations by StopLevel or FreezeLevel ...
   if(method!=ERROR_CODE_PROCESSING_METHOD_OK)
     {
      //--- If trading is completely disabled, set the error code to the return structure,
      //--- display a journal message, play the error sound and exit
      if(method==ERROR_CODE_PROCESSING_METHOD_DISABLE)
        {
         trade_obj.SetResultRetcode(MSG_LIB_TEXT_TRADING_DISABLE);
         trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
         if(this.m_log_level>LOG_LEVEL_NO_MSG)
            ::Print(CMessage::Text(MSG_LIB_TEXT_TRADING_DISABLE));
         if(this.IsUseSounds())
            trade_obj.PlaySoundError(action,order_type);
         return false;
        }
      //--- If the check result is "abort trading operation" - set the last error code to the return structure,
      //--- display a journal message, play the error sound and exit
      if(method==ERROR_CODE_PROCESSING_METHOD_EXIT)
        {
         int code=this.m_list_errors.At(this.m_list_errors.Total()-1);
         if(code!=NULL)
           {
            trade_obj.SetResultRetcode(code);
            trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
           }
         if(this.m_log_level>LOG_LEVEL_NO_MSG)
            ::Print(CMessage::Text(MSG_LIB_TEXT_TRADING_OPERATION_ABORTED));
         if(this.IsUseSounds())
            trade_obj.PlaySoundError(action,order_type);
         return false;
        }
      //--- If the check result is "waiting" - set the last error code to the return structure and display the message in the journal
      if(method==ERROR_CODE_PROCESSING_METHOD_EXIT)
        {
         int code=this.m_list_errors.At(this.m_list_errors.Total()-1);
         if(code!=NULL)
           {
            trade_obj.SetResultRetcode(code);
            trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
           }
         if(this.m_log_level>LOG_LEVEL_NO_MSG)
            ::Print(CMessage::Text(MSG_LIB_TEXT_CREATE_PENDING_REQUEST));
         //--- Instead of creating a pending request, we temporarily wait the required time period (the CheckErrors() method result is returned)
         ::Sleep(method);
         //--- after waiting, update all data
         symbol_obj.Refresh();
        }
      //--- If the check result is "create a pending request", do nothing temporarily
      if(this.m_err_handling_behavior==ERROR_HANDLING_BEHAVIOR_PENDING_REQUEST)
        {
         if(this.m_log_level>LOG_LEVEL_NO_MSG)
            ::Print(CMessage::Text(MSG_LIB_TEXT_CREATE_PENDING_REQUEST));
        }
     }
   
//--- In the loop by the number of attempts
   for(int i=0;i<this.m_total_try;i++)
     {                
      //--- Send the request
      res=trade_obj.OpenPosition(type,this.m_request.volume,this.m_request.sl,this.m_request.tp,magic,comment,deviation);
      //--- If the request is executed successfully or the asynchronous order sending mode is set, play the success sound
      //--- set for a symbol trading object for this type of trading operation and return 'true'
      if(res || trade_obj.IsAsyncMode())
        {
         if(this.IsUseSounds())
            trade_obj.PlaySoundSuccess(action,order_type);
         return true;
        }
      //--- If the request is not successful, play the error sound set for a symbol trading object for this type of trading operation
      else
        {
         if(this.m_log_level>LOG_LEVEL_NO_MSG)
            ::Print(CMessage::Text(MSG_LIB_TEXT_TRY_N),string(i+1),". ",CMessage::Text(MSG_LIB_SYS_ERROR),": ",CMessage::Text(trade_obj.GetResultRetcode()));
         if(this.IsUseSounds())
            trade_obj.PlaySoundError(action,order_type);
         
         //--- Get the error handling method
         method=this.ResultProccessingMethod(trade_obj.GetResultRetcode());
         //--- If "Disable trading for the EA" is received as a result of sending a request, enable the disabling flag and end the attempt loop
         if(method==ERROR_CODE_PROCESSING_METHOD_DISABLE)
           {
            this.SetTradingDisableFlag(true);
            break;
           }
         //--- If "Exit the trading method" is received as a result of sending a request, end the attempt loop
         if(method==ERROR_CODE_PROCESSING_METHOD_EXIT)
           {
            break;
           }
         //--- If "Correct the parameters and repeat" is received as a result of sending a request -
         //--- correct the parameters and start the next iteration
         if(method==ERROR_CODE_PROCESSING_METHOD_CORRECT)
           {
            this.RequestErrorsCorrecting(this.m_request,order_type,trade_obj.SpreadMultiplier(),symbol_obj,trade_obj);
            continue;
           }
         //--- If "Update data and repeat" is received as a result of sending a request -
         //--- update data and start the next iteration
         if(method==ERROR_CODE_PROCESSING_METHOD_REFRESH)
           {
            symbol_obj.Refresh();
            continue;
           }
         //--- If "Wait and repeat" is received as a result of sending a request -
         //--- in this implementation, we wait the number of milliseconds equal to the 'method' value and move on to the next iteration
         if(method==ERROR_CODE_PROCESSING_METHOD_WAIT)
           {
            ::Sleep(method);
            continue;
           }
         //--- If "Create a pending request" is received as a result of sending a request -
         //--- create a pending request with the trading request parameters and end the attempt loop
         if(method==ERROR_CODE_PROCESSING_METHOD_PENDING)
           {
            break;
           }
        }
     }
//--- Return the result of sending a trading request in a symbol trading object
   return res;
  }
//+------------------------------------------------------------------+

在清单中直接为方法进行了详细注释，它是用于开立空头和多头仓位：

//+------------------------------------------------------------------+
//| Open Buy position                                                |
//+------------------------------------------------------------------+
template<typename SL,typename TP> 
bool CTrading::OpenBuy(const double volume,
                       const string symbol,
                       const ulong magic=ULONG_MAX,
                       const SL sl=0,
                       const TP tp=0,
                       const string comment=NULL,
                       const ulong deviation=ULONG_MAX)
  {
//--- Return the result of sending a trading request from the OpenPosition() method
   return this.OpenPosition(POSITION_TYPE_BUY,volume,symbol,magic,sl,tp,comment,deviation);
  }
//+------------------------------------------------------------------+
//| Open a Sell position                                             |
//+------------------------------------------------------------------+
template<typename SL,typename TP> 
bool CTrading::OpenSell(const double volume,
                        const string symbol,
                        const ulong magic=ULONG_MAX,
                        const SL sl=0,
                        const TP tp=0,
                        const string comment=NULL,
                        const ulong deviation=ULONG_MAX)
  {
//--- Return the result of sending a trading request from the OpenPosition() method
   return this.OpenPosition(POSITION_TYPE_SELL,volume,symbol,magic,sl,tp,comment,deviation);
  }
//+------------------------------------------------------------------+

在这些方法中，只是简单地调用按所指示已开仓类型开立仓位的通用私密方法。

实现下挂单的私密方法：

//+------------------------------------------------------------------+
//| Place a pending order                                            |
//+------------------------------------------------------------------+
template<typename PS,typename PL,typename SL,typename TP>
bool CTrading::PlaceOrder(const ENUM_ORDER_TYPE order_type,
                          const double volume,
                          const string symbol,
                          const PS price_stop,
                          const PL price_limit=0,
                          const SL sl=0,
                          const TP tp=0,
                          const ulong magic=ULONG_MAX,
                          const string comment=NULL,
                          const datetime expiration=0,
                          const ENUM_ORDER_TYPE_TIME type_time=WRONG_VALUE,
                          const ENUM_ORDER_TYPE_FILLING type_filling=WRONG_VALUE)
  {
   bool res=true;
   this.m_error_reason_flags=TRADE_REQUEST_ERR_FLAG_NO_ERROR;
   ENUM_ACTION_TYPE action=(ENUM_ACTION_TYPE)order_type;
//--- Get a symbol object by a symbol name
   CSymbol *symbol_obj=this.m_symbols.GetSymbolObjByName(symbol);
   if(symbol_obj==NULL)
     {
      this.m_error_reason_flags=TRADE_REQUEST_ERR_FLAG_INTERNAL_ERR;
      if(this.m_log_level>LOG_LEVEL_NO_MSG)
         ::Print(DFUN,CMessage::Text(MSG_LIB_SYS_ERROR_FAILED_GET_SYM_OBJ));
      return false;
     }
//--- Get a trading object from a symbol object
   CTradeObj *trade_obj=symbol_obj.GetTradeObj();
   if(trade_obj==NULL)
     {
      this.m_error_reason_flags=TRADE_REQUEST_ERR_FLAG_INTERNAL_ERR;
      if(this.m_log_level>LOG_LEVEL_NO_MSG)
         ::Print(DFUN,CMessage::Text(MSG_LIB_SYS_ERROR_FAILED_GET_TRADE_OBJ));
      return false;
     }
//--- Set the prices
//--- If failed to set - write the "internal error" flag, set the error code in the return structure,
//--- display the message in the journal and return 'false'
   if(!this.SetPrices(order_type,price_stop,sl,tp,price_limit,DFUN,symbol_obj))
     {
      this.m_error_reason_flags=TRADE_REQUEST_ERR_FLAG_INTERNAL_ERR;
      trade_obj.SetResultRetcode(10021);
      trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
      if(this.m_log_level>LOG_LEVEL_NO_MSG)
         ::Print(DFUN,CMessage::Text(10021));   // No quotes to process the request
      return false;
     }
     
//--- In case of trading limitations, funds insufficiency,
//--- there are limitations on StopLevel - play the error sound and exit
   this.m_request.volume=volume;
   this.m_request.type_filling=type_filling;
   this.m_request.type_time=type_time;
   this.m_request.expiration=expiration;
   ENUM_ERROR_CODE_PROCESSING_METHOD method=this.CheckErrors(this.m_request.volume,
                                                             this.m_request.price,
                                                             action,
                                                             order_type,
                                                             symbol_obj,
                                                             trade_obj,
                                                             DFUN,
                                                             this.m_request.stoplimit,
                                                             this.m_request.sl,
                                                             this.m_request.tp);
   if(method!=ERROR_CODE_PROCESSING_METHOD_OK)
     {
      //--- If trading is completely disabled
      if(method==ERROR_CODE_PROCESSING_METHOD_DISABLE)
        {
         trade_obj.SetResultRetcode(MSG_LIB_TEXT_TRADING_DISABLE);
         trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
         if(this.m_log_level>LOG_LEVEL_NO_MSG)
            ::Print(CMessage::Text(MSG_LIB_TEXT_TRADING_DISABLE));
         if(this.IsUseSounds())
            trade_obj.PlaySoundError(action,order_type);
         return false;
        }
      //--- If the check result is "abort trading operation" - set the last error code to the return structure,
      //--- display a journal message, play the error sound and exit
      if(method==ERROR_CODE_PROCESSING_METHOD_EXIT)
        {
         int code=this.m_list_errors.At(this.m_list_errors.Total()-1);
         if(code!=NULL)
           {
            trade_obj.SetResultRetcode(code);
            trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
           }
         if(this.m_log_level>LOG_LEVEL_NO_MSG)
            ::Print(CMessage::Text(MSG_LIB_TEXT_TRADING_OPERATION_ABORTED));
         if(this.IsUseSounds())
            trade_obj.PlaySoundError(action,order_type);
         return false;
        }
      //--- If the check result is "waiting" - set the last error code to the return structure and display the message in the journal
      if(method==ERROR_CODE_PROCESSING_METHOD_EXIT)
        {
         int code=this.m_list_errors.At(this.m_list_errors.Total()-1);
         if(code!=NULL)
           {
            trade_obj.SetResultRetcode(code);
            trade_obj.SetResultComment(CMessage::Text(trade_obj.GetResultRetcode()));
           }
         if(this.m_log_level>LOG_LEVEL_NO_MSG)
            ::Print(CMessage::Text(MSG_LIB_TEXT_CREATE_PENDING_REQUEST));
         //--- Instead of creating a pending request, we temporarily wait the required time period (the CheckErrors() method result is returned)
         ::Sleep(method);           
         symbol_obj.Refresh();
        }
      //--- If the check result is "create a pending request", do nothing temporarily
      if(this.m_err_handling_behavior==ERROR_HANDLING_BEHAVIOR_PENDING_REQUEST)
        {
         if(this.m_log_level>LOG_LEVEL_NO_MSG)
            ::Print(CMessage::Text(MSG_LIB_TEXT_CREATE_PENDING_REQUEST));
        }
     }

//--- In the loop by the number of attempts
   for(int i=0;i<this.m_total_try;i++)
     {                
      //--- Send the request
      res=trade_obj.SetOrder(order_type,
                             this.m_request.volume,
                             this.m_request.price,
                             this.m_request.sl,
                             this.m_request.tp,
                             this.m_request.stoplimit,
                             magic,
                             comment,
                             this.m_request.expiration,
                             this.m_request.type_time,
                             this.m_request.type_filling);
      //--- If the request is executed successfully or the asynchronous order sending mode is set, play the success sound
      //--- set for a symbol trading object for this type of trading operation and return 'true'
      if(res || trade_obj.IsAsyncMode())
        {
         if(this.IsUseSounds())
            trade_obj.PlaySoundSuccess(action,order_type);
         return true;
        }
      //--- If the request is not successful, play the error sound set for a symbol trading object for this type of trading operation
      else
        {
         if(this.m_log_level>LOG_LEVEL_NO_MSG)
            ::Print(CMessage::Text(MSG_LIB_TEXT_TRY_N),string(i+1),". ",CMessage::Text(MSG_LIB_SYS_ERROR),": ",CMessage::Text(trade_obj.GetResultRetcode()));
         if(this.IsUseSounds())
            trade_obj.PlaySoundError(action,order_type);
         
         method=this.ResultProccessingMethod(trade_obj.GetResultRetcode());
         //--- If "Disable trading for the EA" is received as a result of sending a request, enable the disabling flag and end the attempt loop
         if(method==ERROR_CODE_PROCESSING_METHOD_DISABLE)
           {
            this.SetTradingDisableFlag(true);
            break;
           }
         //--- If "Exit the trading method" is received as a result of sending a request, end the attempt loop
         if(method==ERROR_CODE_PROCESSING_METHOD_EXIT)
           {
            break;
           }
         //--- If "Correct the parameters and repeat" is received as a result of sending a request -
         //--- correct the parameters and start the next iteration
         if(method==ERROR_CODE_PROCESSING_METHOD_CORRECT)
           {
            this.RequestErrorsCorrecting(this.m_request,order_type,trade_obj.SpreadMultiplier(),symbol_obj,trade_obj);
            continue;
           }
         //--- If "Update data and repeat" is received as a result of sending a request -
         //--- update data and start the next iteration
         if(method==ERROR_CODE_PROCESSING_METHOD_REFRESH)
           {
            symbol_obj.Refresh();
            continue;
           }
         //--- If "Wait and repeat" is received as a result of sending a request -
         //--- in this implementation, we wait the number of milliseconds equal to the 'method' value and move on to the next iteration
         if(method==ERROR_CODE_PROCESSING_METHOD_WAIT)
           {
            Sleep(method);
            continue;
           }
         //--- If "Create a pending request" is received as a result of sending a request -
         //--- create a pending request with the trading request parameters and end the attempt loop
         if(method==ERROR_CODE_PROCESSING_METHOD_PENDING)
           {
            break;
           }
        }
     }
//--- Return the result of sending a trading request in a symbol trading object
   return res;
  }
//+------------------------------------------------------------------+

在清单中直接为此方法进行了详细注释，它是用于设置挂单的各种类型：

//+------------------------------------------------------------------+
//| Place BuyStop pending order                                      |
//+------------------------------------------------------------------+
template<typename PS,typename SL,typename TP>
bool CTrading::PlaceBuyStop(const double volume,
                            const string symbol,
                            const PS price,
                            const SL sl=0,
                            const TP tp=0,
                            const ulong magic=ULONG_MAX,
                            const string comment=NULL,
                            const datetime expiration=0,
                            const ENUM_ORDER_TYPE_TIME type_time=WRONG_VALUE,
                            const ENUM_ORDER_TYPE_FILLING type_filling=WRONG_VALUE)
  {
//--- Return the result of sending a trading request using the PlaceOrder() method
   return this.PlaceOrder(ORDER_TYPE_BUY_STOP,volume,symbol,price,0,sl,tp,magic,comment,expiration,type_time,type_filling);
  }
//+------------------------------------------------------------------+
//| Place BuyLimit pending order                                     |
//+------------------------------------------------------------------+
template<typename PS,typename SL,typename TP>
bool CTrading::PlaceBuyLimit(const double volume,
                             const string symbol,
                             const PS price,
                             const SL sl=0,
                             const TP tp=0,
                             const ulong magic=ULONG_MAX,
                             const string comment=NULL,
                             const datetime expiration=0,
                             const ENUM_ORDER_TYPE_TIME type_time=WRONG_VALUE,
                             const ENUM_ORDER_TYPE_FILLING type_filling=WRONG_VALUE)
  {
//--- Return the result of sending a trading request using the PlaceOrder() method
   return this.PlaceOrder(ORDER_TYPE_BUY_LIMIT,volume,symbol,price,0,sl,tp,magic,comment,expiration,type_time,type_filling);
  }
//+------------------------------------------------------------------+
//| Place BuyStopLimit pending order                                 |
//+------------------------------------------------------------------+
template<typename PS,typename PL,typename SL,typename TP>
bool CTrading::PlaceBuyStopLimit(const double volume,
                                 const string symbol,
                                 const PS price_stop,
                                 const PL price_limit,
                                 const SL sl=0,
                                 const TP tp=0,
                                 const ulong magic=ULONG_MAX,
                                 const string comment=NULL,
                                 const datetime expiration=0,
                                 const ENUM_ORDER_TYPE_TIME type_time=WRONG_VALUE,
                                 const ENUM_ORDER_TYPE_FILLING type_filling=WRONG_VALUE)
  {
#ifdef __MQL5__
//--- Return the result of sending a trading request using the PlaceOrder() method
   return this.PlaceOrder(ORDER_TYPE_BUY_STOP_LIMIT,volume,symbol,price_stop,price_limit,sl,tp,magic,comment,expiration,type_time,type_filling);
//--- MQL4
#else 
   return true;
#endif 
  }
//+------------------------------------------------------------------+
//| Place SellStop pending order                                     |
//+------------------------------------------------------------------+
template<typename PS,typename SL,typename TP>
bool CTrading::PlaceSellStop(const double volume,
                             const string symbol,
                             const PS price,
                             const SL sl=0,
                             const TP tp=0,
                             const ulong magic=ULONG_MAX,
                             const string comment=NULL,
                             const datetime expiration=0,
                             const ENUM_ORDER_TYPE_TIME type_time=WRONG_VALUE,
                             const ENUM_ORDER_TYPE_FILLING type_filling=WRONG_VALUE)
  {
//--- Return the result of sending a trading request using the PlaceOrder() method
   return this.PlaceOrder(ORDER_TYPE_SELL_STOP,volume,symbol,price,0,sl,tp,magic,comment,expiration,type_time,type_filling);
  }
//+------------------------------------------------------------------+
//| Place SellLimit pending order                                    |
//+------------------------------------------------------------------+
template<typename PS,typename SL,typename TP>
bool CTrading::PlaceSellLimit(const double volume,
                              const string symbol,
                              const PS price,
                              const SL sl=0,
                              const TP tp=0,
                              const ulong magic=ULONG_MAX,
                              const string comment=NULL,
                              const datetime expiration=0,
                              const ENUM_ORDER_TYPE_TIME type_time=WRONG_VALUE,
                              const ENUM_ORDER_TYPE_FILLING type_filling=WRONG_VALUE)
  {
//--- Return the result of sending a trading request using the PlaceOrder() method
   return this.PlaceOrder(ORDER_TYPE_SELL_LIMIT,volume,symbol,price,0,sl,tp,magic,comment,expiration,type_time,type_filling);
  }
//+------------------------------------------------------------------+
//| Place SellStopLimit pending order                                |
//+------------------------------------------------------------------+
template<typename PS,typename PL,typename SL,typename TP>
bool CTrading::PlaceSellStopLimit(const double volume,
                                  const string symbol,
                                  const PS price_stop,
                                  const PL price_limit,
                                  const SL sl=0,
                                  const TP tp=0,
                                  const ulong magic=ULONG_MAX,
                                  const string comment=NULL,
                                  const datetime expiration=0,
                                  const ENUM_ORDER_TYPE_TIME type_time=WRONG_VALUE,
                                  const ENUM_ORDER_TYPE_FILLING type_filling=WRONG_VALUE)
  {
#ifdef __MQL5__
//--- Return the result of sending a trading request using the PlaceOrder() method
   return this.PlaceOrder(ORDER_TYPE_SELL_STOP_LIMIT,volume,symbol,price_stop,price_limit,sl,tp,magic,comment,expiration,type_time,type_filling);
   //--- MQL4
#else 
   return true;
#endif 
  }
//+------------------------------------------------------------------+

其余的方法对于平仓和删除挂单是必需的。 修改持仓和订单的方法类似于开仓/下挂单的私密方法。 所有方法代码都有详细的注释。 全部文件都附带于下。

交易类的所有工作至此完毕。

现在只需要针对函数库的 CEngine 基准对象类进行一些修改。

考虑到最小停止和挂单级别（StopLevel）的浮动性质，我们需要设置点差倍数，因为在这种情况下经常采用点差乘以某个值来指定可接受的停止单距离。 这意味着我们需要能够为交易类设置点差倍数的方法。
在类的公开部分声明以下方法：

//--- Set the spread multiplier for symbol trading objects in the symbol collection
   void                 SetSpreadMultiplier(const uint value=1,const string symbol=NULL)  { this.m_trading.SetSpreadMultiplier(value,symbol);   }

//--- Open (1) Buy, (2) Sell position

该方法简单地调用我们在上一篇文章中已经试验过的同名交易类方法，它能够为所有用到的品种设置单一的通用倍数，也可以为指定品种设置单独倍数。

由于交易类将很快采用计时器来处理延后请求，因此在 CEngine 类构造函数中为交易类的计时器创建了新计数器：

//+------------------------------------------------------------------+
//| CEngine constructor                                              |
//+------------------------------------------------------------------+
CEngine::CEngine() : m_first_start(true),
                     m_last_trade_event(TRADE_EVENT_NO_EVENT),
                     m_last_account_event(WRONG_VALUE),
                     m_last_symbol_event(WRONG_VALUE),
                     m_global_error(ERR_SUCCESS)
  {
   this.m_is_hedge=#ifdef __MQL4__ true #else bool(::AccountInfoInteger(ACCOUNT_MARGIN_MODE)==ACCOUNT_MARGIN_MODE_RETAIL_HEDGING) #endif;
   this.m_is_tester=::MQLInfoInteger(MQL_TESTER);
   
   this.m_list_counters.Sort();
   this.m_list_counters.Clear();
   this.CreateCounter(COLLECTION_ORD_COUNTER_ID,COLLECTION_ORD_COUNTER_STEP,COLLECTION_ORD_PAUSE);
   this.CreateCounter(COLLECTION_ACC_COUNTER_ID,COLLECTION_ACC_COUNTER_STEP,COLLECTION_ACC_PAUSE);

   this.CreateCounter(COLLECTION_SYM_COUNTER_ID1,COLLECTION_SYM_COUNTER_STEP1,COLLECTION_SYM_PAUSE1);
   this.CreateCounter(COLLECTION_SYM_COUNTER_ID2,COLLECTION_SYM_COUNTER_STEP2,COLLECTION_SYM_PAUSE2);
   this.CreateCounter(COLLECTION_REQ_COUNTER_ID,COLLECTION_REQ_COUNTER_STEP,COLLECTION_REQ_PAUSE);
   
   ::ResetLastError();
   #ifdef __MQL5__
      if(!::EventSetMillisecondTimer(TIMER_FREQUENCY))
        {
         ::Print(DFUN_ERR_LINE,CMessage::Text(MSG_LIB_SYS_FAILED_CREATE_TIMER),(string)::GetLastError());
         this.m_global_error=::GetLastError();
        }
   //---__MQL4__
   #else 
      if(!this.IsTester() && !::EventSetMillisecondTimer(TIMER_FREQUENCY))
        {
         ::Print(DFUN_ERR_LINE,CMessage::Text(MSG_LIB_SYS_FAILED_CREATE_TIMER),(string)::GetLastError());
         this.m_global_error=::GetLastError();
        }
   #endif 
   //---
  }
//+------------------------------------------------------------------+

在 CEngine 类的计时器中，添加操控交易类计时器的模块：

//+------------------------------------------------------------------+
//| CEngine timer                                                    |
//+------------------------------------------------------------------+
void CEngine::OnTimer(void)
  {
//--- Timer of the collections of historical orders and deals, as well as of market orders and positions
   int index=this.CounterIndex(COLLECTION_ORD_COUNTER_ID);
   if(index>WRONG_VALUE)
     {
      CTimerCounter* counter=this.m_list_counters.At(index);
      if(counter!=NULL)
        {
         //--- If this is not a tester
         if(!this.IsTester())
           {
            //--- If unpaused, work with the order, deal and position collections events
            if(counter.IsTimeDone())
               this.TradeEventsControl();
           }
         //--- If this is a tester, work with collection events by tick
         else
            this.TradeEventsControl();
        }
     }
//--- Account collection timer
   index=this.CounterIndex(COLLECTION_ACC_COUNTER_ID);
   if(index>WRONG_VALUE)
     {
      CTimerCounter* counter=this.m_list_counters.At(index);
      if(counter!=NULL)
        {
         //--- If this is not a tester
         if(!this.IsTester())
           {
            //--- If unpaused, work with the account collection events
            if(counter.IsTimeDone())
               this.AccountEventsControl();
           }
         //--- If this is a tester, work with collection events by tick
         else
            this.AccountEventsControl();
        }
     }
     
//--- Timer 1 of the symbol collection (updating symbol quote data in the collection)
   index=this.CounterIndex(COLLECTION_SYM_COUNTER_ID1);
   if(index>WRONG_VALUE)
     {
      CTimerCounter* counter=this.m_list_counters.At(index);
      if(counter!=NULL)
        {
         //--- If this is not a tester
         if(!this.IsTester())
           {
            //--- If the pause is over, update quote data of all symbols in the collection
            if(counter.IsTimeDone())
               this.m_symbols.RefreshRates();
           }
         //--- In case of a tester, update quote data of all collection symbols by tick
         else
            this.m_symbols.RefreshRates();
        }
     }
//--- Timer 2 of the symbol collection (updating all data of all symbols in the collection and tracking symbl and symbol search events in the market watch window)
   index=this.CounterIndex(COLLECTION_SYM_COUNTER_ID2);
   if(index>WRONG_VALUE)
     {
      CTimerCounter* counter=this.m_list_counters.At(index);
      if(counter!=NULL)
        {
         //--- If this is not a tester
         if(!this.IsTester())
           {
            //--- If the pause is over
            if(counter.IsTimeDone())
              {
               //--- update data and work with events of all symbols in the collection
               this.SymbolEventsControl();
               //--- When working with the market watch list, check the market watch window events
               if(this.m_symbols.ModeSymbolsList()==SYMBOLS_MODE_MARKET_WATCH)
                  this.MarketWatchEventsControl();
              }
           }
         //--- If this is a tester, work with events of all symbols in the collection by tick
         else
            this.SymbolEventsControl();
        }
     }
//--- Trading class timer
   index=this.CounterIndex(COLLECTION_REQ_COUNTER_ID);
   if(index>WRONG_VALUE)
     {
      CTimerCounter* counter=this.m_list_counters.At(index);
      if(counter!=NULL)
        {
         //--- If this is not a tester
         if(!this.IsTester())
           {
            //--- If unpaused, work with the list of pending requests
            if(counter.IsTimeDone())
               this.m_trading.OnTimer();
           }
         //--- In case of the tester, work with the list of pending orders by tick
         else
            this.m_trading.OnTimer();
        }
     }   
  }
//+------------------------------------------------------------------+

完全平仓的方法也略有修改：

//+------------------------------------------------------------------+
//| Close a position in full                                         |
//+------------------------------------------------------------------+
bool CEngine::ClosePosition(const ulong ticket,const string comment=NULL,const ulong deviation=ULONG_MAX)
  {
   return this.m_trading.ClosePosition(ticket,WRONG_VALUE,comment,deviation);
  }
//+------------------------------------------------------------------+

由于我们现在已拥有完全和部分平仓的通用方法，因此我们需要传递 -1 作为完全平仓的平仓量。

处理交易服务器返回码的必要修改和改进至此完毕。

测试

为了检查依据交易服务器返回错误进行的处理，合理的做法是设置导致错误的交易条件，例如执行延迟。 在延迟期间，价格变化会导致相应的错误。

为了执行测试，我们利用上一篇文章中的 EA，并将其保存到 \MQL5\Experts\TestDoEasy\Part25\，命名为 TestDoEasyPart25.mq5。

虽然我们可以不加任何修改地启动 EA，但我们还是先进行一些改进。
在 EA 输入模块中，将默认滑点从零改为五个点，并添加点差倍数：

//--- input variables
input    ulong             InpMagic             =  123;  // Magic number
input    double            InpLots              =  0.1;  // Lots
input    uint              InpStopLoss          =  50;   // StopLoss in points
input    uint              InpTakeProfit        =  50;   // TakeProfit in points
input    uint              InpDistance          =  50;   // Pending orders distance (points)
input    uint              InpDistanceSL        =  50;   // StopLimit orders distance (points)
input    uint              InpSlippage          =  5;    // Slippage in points
input    uint              InpSpreadMultiplier  =  1;    // Spread multiplier for adjusting stop-orders by StopLevel
sinput   double            InpWithdrawal        =  10;   // Withdrawal funds (in tester)
sinput   uint              InpButtShiftX        =  40;   // Buttons X shift 
sinput   uint              InpButtShiftY        =  10;   // Buttons Y shift 
input    uint              InpTrailingStop      =  50;   // Trailing Stop (points)
input    uint              InpTrailingStep      =  20;   // Trailing Step (points)
input    uint              InpTrailingStart     =  0;    // Trailing Start (points)
input    uint              InpStopLossModify    =  20;   // StopLoss for modification (points)
input    uint              InpTakeProfitModify  =  60;   // TakeProfit for modification (points)
sinput   ENUM_SYMBOLS_MODE InpModeUsedSymbols   =  SYMBOLS_MODE_CURRENT;   // Mode of used symbols list
sinput   string            InpUsedSymbols       =  "EURUSD,AUDUSD,EURAUD,EURCAD,EURGBP,EURJPY,EURUSD,GBPUSD,NZDUSD,USDCAD,USDJPY";  // List of used symbols (comma - separator)
sinput   bool              InpUseSounds         =  true; // Use sounds

在函数库初始化函数中，为所有用到的品种的所有交易对象设置点差倍数，为避免跟踪和在测试器日志里发送多余的记录，将控制增加品种参数值的代码块注释掉：

//+------------------------------------------------------------------+
//| Initializing DoEasy library                                      |
//+------------------------------------------------------------------+
void OnInitDoEasy()
  {
//--- Check if working with the full list is selected
   used_symbols_mode=InpModeUsedSymbols;
   if((ENUM_SYMBOLS_MODE)used_symbols_mode==SYMBOLS_MODE_ALL)
     {
      int total=SymbolsTotal(false);
      string ru_n="\nКоличество символов на сервере "+(string)total+".\nМаксимальное количество: "+(string)SYMBOLS_COMMON_TOTAL+" символов.";
      string en_n="\nNumber of symbols on server "+(string)total+".\nMaximum number: "+(string)SYMBOLS_COMMON_TOTAL+" symbols.";
      string caption=TextByLanguage("Внимание!","Attention!");
      string ru="Выбран режим работы с полным списком.\nВ этом режиме первичная подготовка списка коллекции символов может занять длительное время."+ru_n+"\nПродолжить?\n\"Нет\" - работа с текущим символом \""+Symbol()+"\"";
      string en="Full list mode selected.\nIn this mode, the initial preparation of the collection symbols list may take a long time."+en_n+"\nContinue?\n\"No\" - working with the current symbol \""+Symbol()+"\"";
      string message=TextByLanguage(ru,en);
      int flags=(MB_YESNO | MB_ICONWARNING | MB_DEFBUTTON2);
      int mb_res=MessageBox(message,caption,flags);
      switch(mb_res)
        {
         case IDNO : 
           used_symbols_mode=SYMBOLS_MODE_CURRENT; 
           break;
         default:
           break;
        }
     }
//--- Fill in the array of used symbols
   used_symbols=InpUsedSymbols;
   CreateUsedSymbolsArray((ENUM_SYMBOLS_MODE)used_symbols_mode,used_symbols,array_used_symbols);

//--- Set the type of the used symbol list in the symbol collection
   engine.SetUsedSymbols(array_used_symbols);
//--- Displaying the selected mode of working with the symbol object collection
   Print(engine.ModeSymbolsListDescription(),TextByLanguage(". Number of used symbols: ",". Number of symbols used: "),engine.GetSymbolsCollectionTotal());
   
//--- Create resource text files
   engine.CreateFile(FILE_TYPE_WAV,"sound_array_coin_01",TextByLanguage("Звук упавшей монетки 1","Falling coin 1"),sound_array_coin_01);
   engine.CreateFile(FILE_TYPE_WAV,"sound_array_coin_02",TextByLanguage("Звук упавших монеток","Falling coins"),sound_array_coin_02);
   engine.CreateFile(FILE_TYPE_WAV,"sound_array_coin_03",TextByLanguage("Звук монеток","Coins"),sound_array_coin_03);
   engine.CreateFile(FILE_TYPE_WAV,"sound_array_coin_04",TextByLanguage("Звук упавшей монетки 2","Falling coin 2"),sound_array_coin_04);
   engine.CreateFile(FILE_TYPE_WAV,"sound_array_click_01",TextByLanguage("Звук щелчка по кнопке 1","Button click 1"),sound_array_click_01);
   engine.CreateFile(FILE_TYPE_WAV,"sound_array_click_02",TextByLanguage("Звук щелчка по кнопке 2","Button click 2"),sound_array_click_02);
   engine.CreateFile(FILE_TYPE_WAV,"sound_array_click_03",TextByLanguage("Звук щелчка по кнопке 3","Button click 3"),sound_array_click_03);
   engine.CreateFile(FILE_TYPE_WAV,"sound_array_cash_machine_01",TextByLanguage("Звук кассового аппарата","Cash machine"),sound_array_cash_machine_01);
   engine.CreateFile(FILE_TYPE_BMP,"img_array_spot_green",TextByLanguage("Изображение \"Зелёный светодиод\"","Image \"Green Spot lamp\""),img_array_spot_green);
   engine.CreateFile(FILE_TYPE_BMP,"img_array_spot_red",TextByLanguage("Изображение \"Красный светодиод\"","Image \"Red Spot lamp\""),img_array_spot_red);

//--- Pass all existing collections to the trading class
   engine.TradingOnInit();
//--- Set synchronous passing of orders for all used symbols
   engine.TradingSetAsyncMode(false);
//--- Set standard sounds for trading objects of all used symbols
   engine.SetSoundsStandart();
//--- Set the general flag of using sounds
   engine.SetUseSounds(InpUseSounds);
//--- Set the spread multiplier for symbol trading objects in the symbol collection
   engine.SetSpreadMultiplier(InpSpreadMultiplier);
      
//--- Set controlled values for symbols
   //--- Get the list of all collection symbols
   CArrayObj *list=engine.GetListAllUsedSymbols();
   if(list!=NULL && list.Total()!=0)
     {
      //--- In a loop by the list, set the necessary values for tracked symbol properties
      //--- By default, the LONG_MAX value is set to all properties, which means "Do not track this property" 
      //--- It can be enabled or disabled (by setting the value less than LONG_MAX or vice versa - set the LONG_MAX value) at any time and anywhere in the program
      /*
      for(int i=0;i<list.Total();i++)
        {
         CSymbol* symbol=list.At(i);
         if(symbol==NULL)
            continue;
         //--- Set control of the symbol price increase by 100 points
         symbol.SetControlBidInc(100000*symbol.Point());
         //--- Set control of the symbol price decrease by 100 points
         symbol.SetControlBidDec(100000*symbol.Point());
         //--- Set control of the symbol spread increase by 40 points
         symbol.SetControlSpreadInc(400);
         //--- Set control of the symbol spread decrease by 40 points
         symbol.SetControlSpreadDec(400);
         //--- Set control of the current spread by the value of 40 points
         symbol.SetControlSpreadLevel(400);
        }
      */
     }
//--- Set controlled values for the current account
   CAccount* account=engine.GetAccountCurrent();
   if(account!=NULL)
     {
      //--- Set control of the profit increase to 10
      account.SetControlledValueINC(ACCOUNT_PROP_PROFIT,10.0);
      //--- Set control of the funds increase to 15
      account.SetControlledValueINC(ACCOUNT_PROP_EQUITY,15.0);
      //--- Set profit control level to 20
      account.SetControlledValueLEVEL(ACCOUNT_PROP_PROFIT,20.0);
     }
  }
//+------------------------------------------------------------------+

在策略测试器中将执行延迟设置为 4 秒。
为此，在下拉菜单中选择 "Custom delay ..."

... 然后在新的输入字段中输入 4000 毫秒：

现在，所有发送到服务器的交易订单在测试器中都会延迟四秒钟。

以可视模式启动 EA，在价格变化足够快的市场里多次尝试迅速开仓，然后全部平仓：

如我们所见，并非总是可以顺利开仓，有时我们会得到重新报价。 EA 会进行必要数量的交易尝试（默认不超过五次）。 这可以通过“Trading attempt(交易尝试)”记录得以确认，该记录指定了尝试次数，并以“Requote（重新报价）”为特征字。 当同时平仓时，我们再次获得重新报价。 最后一笔持仓经历五次尝试后，仍未被平仓。 在几次尝试失败后，我设法手动将其平仓。 无论如何，EA 遵照指定的重复交易尝试数量，运行了函数库内置算法。

在最新的 MetaTrader 5 版本中（自 build 2201 开始），测试器提供了在测试执行期间为品种设置参数的能力。 因此，可以在品种上设置交易限制，并在检测到品种限制时测试函数库行为。

若要调用品种设置窗口，单击测试时间帧选择右侧的按钮：

一个品种只允许开立多头仓位，并将同时开仓和同向挂单的交易量限制为 0.5。

因此，我们将只能使用多头仓位，且最大的多头持仓和订单总交易量不超过 0.5 手。 换言之，当多头开仓 0.1 手时，我们只能开五笔，或四笔持仓加一笔挂单：

为了提高真实性，我们可以禁用超过指定利润时的自动平仓。 不过，我们看到我们无法开立空头持仓，并会收到警告，该品种只允许开立多头仓位。 进而，当尝试开立总交易量超过 0.5 手的多笔持仓时，我们会收到消息：由于超出一个方向的持仓和订单总交易量而无法开仓。

自终端 beta build 2201 版本开始，您可在测试器中测试此功能，以及与品种参数相关的许多其他功能。
若要获取终端的最新 Beta 版本，只需连接到 MetaQuotes-Demo，并在“帮助”菜单中选择“最新 Beta 版本”：

下一步是什么？

在下一篇文章中，我们将实现延后交易请求。

文后附有当前版本含糊库的所有文件，以及测试 EA 文件，供您测试和下载。
请在评论中留下您的问题、意见和建议。

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