How create static trendline object on chart by MQL4?

Question

I want a down trend line whenever the highest candle in the previous 500 bars is higher than latest 5 candles highest bar. However the trend line is created the first time but does not update.

int highestCandle=iHighest(Symbol(),0,MODE_HIGH,500,0);
if(High[highestCandle]>High[5])
{
ObjectCreate(0,"HT",OBJ_TREND,0,Time[highestCandle],High[highestCandle],Time[0],High[0]);
ObjectSetInteger(0,"HT",OBJPROP_COLOR,clrBlue); ObjectSetInteger(0,"HT",OBJPROP_STYLE,STYLE_SOLID); ObjectSetInteger(0,"HT",OBJPROP_RAY,true);
}

I do not want to delete this object and recreate on every new tick, I would just like it to be updated on the chart.

Answer 1

Because you have already created your object, trying to create it again will not move the coordinates. You need to use ObjectMove. Try the following code:

int highestCandle=iHighest(Symbol(),0,MODE_HIGH,500,0);
if(High[highestCandle]>High[5])
{
   ObjectCreate(0,"HT",OBJ_TREND,0,Time[highestCandle],High[highestCandle],Time[0],High[0]);
   ObjectSetInteger(0,"HT",OBJPROP_COLOR,clrBlue);
   ObjectSetInteger(0,"HT",OBJPROP_STYLE,STYLE_SOLID); 
   ObjectSetInteger(0,"HT",OBJPROP_RAY,true);
   ObjectMove("HT",0,Time[highestCandle],High[highestCandle]);
   ObjectMove("HT",1,Time[0],High[0]);
}