【MQL5】水平ラインを引く①

#property indicator_chart_window
#property indicator_buffers 1 
#property indicator_plots 1

input ENUM_TIMEFRAMES Rate_TimeFrame = PERIOD_D1; //タイムフレーム
input int RatesCount      =120;                   //計算対象となるローソク足の本数
input color HighLineColor =clrHotPink;            //最高値ラインの色
input color LowLineColor  =clrHotPink;            //最安値ラインの色

string HighLineName      ="HgihLine";             //チャートに描画する最高値ラインの名称
string LowLineName       ="LowLine";              //チャートに描画する最安値ラインの名称

//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int OnInit()
  {
    //最高値ラインの生成
    ObjectCreate(0,HighLineName,OBJ_HLINE,0,0,0);   
    ObjectSetInteger(0,HighLineName,OBJPROP_COLOR,HighLineColor);
    //最安値ラインの生成
    ObjectCreate(0,LowLineName,OBJ_HLINE,0,0,0);   
    ObjectSetInteger(0,LowLineName,OBJPROP_COLOR,LowLineColor);
              
    return(INIT_SUCCEEDED);
  }
//+------------------------------------------------------------------+
//| Expert deinitialization function                                 |
//+------------------------------------------------------------------+
void OnDeinit(const int reason)
  {
    //オブジェクトの削除
    ObjectsDeleteAll(0,-1,-1);
  }  
//+------------------------------------------------------------------+
//| Custom indicator iteration function                              |
//+------------------------------------------------------------------+
int OnCalculate(const int rates_total,
                const int prev_calculated,
                const datetime &time[],
                const double &open[],
                const double &high[],
                const double &low[],
                const double &close[],
                const long &tick_volume[],
                const long &volume[],
                const int &spread[])    
  {
     
    MqlRates rt[];
    if(CopyRates(_Symbol,Rate_TimeFrame,0,RatesCount,rt)!=RatesCount)
      {
        Print("チャート履歴の取得に失敗しました!");
        return(rates_total);
      }
       
    double Price_High =0;
    double Price_Low   =0;      
    for(int i=0;i<RatesCount;i++)
      {
        //最高値
        if(rt[i].high>Price_High || Price_High==0){Price_High=rt[i].high;}
        //最安値
        if(rt[i].low<Price_Low || Price_Low==0){Price_Low=rt[i].low;}         
      }

    ObjectMove(0,HighLineName,0,0,NormalizeDouble(Price_High,_Digits));
    ObjectMove(0,LowLineName,0,0,NormalizeDouble(Price_Low,_Digits));
             
   return(rates_total);
  }