GetDouble

Provides simplified access to the functions of API MQL5 ObjectGetDouble() to receive double values (of float and double types) of a graphical object bound to a class instance. There are two versions of the function call:

Getting a property value without checking the correctness

double  GetDouble(
   ENUM_OBJECT_PROPERTY_DOUBLE  prop_id,         // integer property ID
   int                          modifier=-1      // modifier
   ) const

Parameters

prop_id

[in] ID of the graphical object double property.

modifier=-1

[in] Modifier (index) of a double property.

Return Value

Value of a double property - success, EMPTY_VALUE - cannot receive a double property.

Getting a property value in verifying the correctness of such treatment

bool  GetDouble(
   ENUM_OBJECT_PROPERTY_DOUBLE  prop_id,      // double property ID
   int                          modifier,     // modifier
   double&                      value         // link to a variable
   ) const

Parameters

prop_id

[in] ID of a graphical object double property.

modifier

[in] Modifier (index) of a double property.

value

[out] Link to a variable to place a double property value.

Return Value

true - success, false - cannot get a double property.

Example:

//--- example for CChartObject::GetDouble
#include <ChartObjects\ChartObject.mqh>
//---
void OnStart()
  {
   CChartObject object;
   //---
   for(int i=0;i<object.LevelsCount();i++)
     {
      //--- get levels value by easy method
      printf("Level %d value=%f",i,object.GetDouble(OBJPROP_LEVELVALUE,i));
      //--- get levels value by classic method
      double value;
      if(!object.SetDouble(OBJPROP_LEVELVALUE,i,value))
        {
         printf("Get double property error %d",GetLastError());
         return;
        }
      else
         printf("Level %d value=%f",i,value);
     }
  }