iWPRSignAlert：MetaTrader 5的信号指示器解析

iWPRSignAlert是一款基于经典Williams百分比范围振荡器的信号指示器，这款指示器能够有效识别超买和超卖区域，并提供实时警报功能，包括邮件和移动设备推送通知。

为了实现这些警报功能，开发者对指示器代码进行了以下几项修改：

1. 引入了新的输入参数：

   inputuint NumberofBar=1;//信号的K线数量inputbool SoundON=true; //启用声音警报inputuint NumberofAlerts=2;//警报次数inputbool EMailON=false; //启用邮件通知inputbool PushON=false; //启用推送通知

2. 在指示器代码末尾添加了三个新功能：BuySignal()、SellSignal()和GetStringTimeframe()

   //+------------------------------------------------------------------+//| 买入信号函数                           |//+------------------------------------------------------------------+void BuySignal(string SignalSirname,      // 指示器名称的文本，用于邮件和推送消息
                  double &BuyArrow[],        // 包含买入信号的指示器缓冲区
                  constint Rates_total,     // 当前K线数量
                  constint Prev_calculated, // 上一根K线数量
                  constdouble &Close[],     // 收盘价
                  constint &Spread[])       // 点差
     {
   //---
      staticuint counter=0;
      if(Rates_total!=Prev_calculated) counter=0;
   
      bool BuySignal=false;
      bool SeriesTest=ArrayGetAsSeries(BuyArrow);
      int index;
      if(SeriesTest) index=int(NumberofBar);
      else index=Rates_total-int(NumberofBar)-1;
      if(NormalizeDouble(BuyArrow[index],_Digits) && BuyArrow[index]!=EMPTY_VALUE) BuySignal=true;
      if(BuySignal && counter<=NumberofAlerts)
        {
         counter++;
         MqlDateTime tm;
         TimeToStruct(TimeCurrent(),tm);
         string text=TimeToString(TimeCurrent(),TIME_DATE)+" "+string(tm.hour)+":"+string(tm.min);
         SeriesTest=ArrayGetAsSeries(Close);
         if(SeriesTest) index=int(NumberofBar);
         else index=Rates_total-int(NumberofBar)-1;
         doubleAsk=Close[index];
         doubleBid=Close[index];
         SeriesTest=ArrayGetAsSeries(Spread);
         if(SeriesTest) index=int(NumberofBar);
         else index=Rates_total-int(NumberofBar)-1;
         Bid+=Spread[index];
         string sAsk=DoubleToString(Ask,_Digits);
         string sBid=DoubleToString(Bid,_Digits);
         string sPeriod=GetStringTimeframe(ChartPeriod());
         if(SoundON) Alert("BUY 信号 
    Ask=",Ask,"
    Bid=",Bid,"
    currtime=",text,"
    Symbol=",Symbol()," Period=",sPeriod);
         if(EMailON) SendMail(SignalSirname+": BUY signal alert","BUY signal at Ask="+sAsk+", Bid="+sBid+", Date="+text+" Symbol="+Symbol()+" Period="+sPeriod);
         if(PushON) SendNotification(SignalSirname+": BUY signal at Ask="+sAsk+", Bid="+sBid+", Date="+text+" Symbol="+Symbol()+" Period="+sPeriod);
        }
   
   //---
     }
   //+------------------------------------------------------------------+//| 卖出信号函数                            |//+------------------------------------------------------------------+void SellSignal(string SignalSirname,      // 指示器名称的文本，用于邮件和推送消息
                   double &SellArrow[],       // 包含卖出信号的指示器缓冲区
                   constint Rates_total,     // 当前K线数量
                   constint Prev_calculated, // 上一根K线数量
                   constdouble &Close[],     // 收盘价
                   constint &Spread[])       // 点差
     {
   //---
      staticuint counter=0;
      if(Rates_total!=Prev_calculated) counter=0;
   
      bool SellSignal=false;
      bool SeriesTest=ArrayGetAsSeries(SellArrow);
      int index;
      if(SeriesTest) index=int(NumberofBar);
      else index=Rates_total-int(NumberofBar)-1;
      if(NormalizeDouble(SellArrow[index],_Digits) && SellArrow[index]!=EMPTY_VALUE) SellSignal=true;
      if(SellSignal && counter<=NumberofAlerts)
        {
         counter++;
         MqlDateTime tm;
         TimeToStruct(TimeCurrent(),tm);
         string text=TimeToString(TimeCurrent(),TIME_DATE)+" "+string(tm.hour)+":"+string(tm.min);
         SeriesTest=ArrayGetAsSeries(Close);
         if(SeriesTest) index=int(NumberofBar);
         else index=Rates_total-int(NumberofBar)-1;
         doubleAsk=Close[index];
         doubleBid=Close[index];
         SeriesTest=ArrayGetAsSeries(Spread);
         if(SeriesTest) index=int(NumberofBar);
         else index=Rates_total-int(NumberofBar)-1;
         Bid+=Spread[index];
         string sAsk=DoubleToString(Ask,_Digits);
         string sBid=DoubleToString(Bid,_Digits);
         string sPeriod=GetStringTimeframe(ChartPeriod());
         if(SoundON) Alert("SELL 信号 
    Ask=",Ask,"
    Bid=",Bid,"
    currtime=",text,"
    Symbol=",Symbol()," Period=",sPeriod);
         if(EMailON) SendMail(SignalSirname+": SELL signal alert","SELL signal at Ask="+sAsk+", Bid="+sBid+", Date="+text+" Symbol="+Symbol()+" Period="+sPeriod);
         if(PushON) SendNotification(SignalSirname+": SELL signal at Ask="+sAsk+", Bid="+sBid+", Date="+text+" Symbol="+Symbol()+" Period="+sPeriod);
        }
   //---
     }
   //+------------------------------------------------------------------+//|  获取时间框架字符串                               |//+------------------------------------------------------------------+string GetStringTimeframe(ENUM_TIMEFRAMES timeframe)
     {
   //----
      return(StringSubstr(EnumToString(timeframe),7,-1));
   //----
     }
   

3. 在OnCalculate()代码块的指示器计算周期后，添加了BuySignal()和SellSignal()函数的调用：

   BuySignal("iWPRSign",BuyBuffer,rates_total,prev_calculated,close,spread);
       SellSignal("iWPRSign",SellBuffer,rates_total,prev_calculated,close,spread);
   

其中，BuyBuffer和SellBuffer是用于存储买入和卖出信号的指示器缓冲区。必须将指示器缓冲区中的空值设置为零或EMPTY_VALUE。

预计在指示器代码的OnCalculate()块中，只会调用一次BuySignal()和SellSignal()函数。

图1：iWPRSignAlert指示器在图表上

图2：iWPRSignAlert指示器生成警报。