MQL4 Reference Constants, Enumerations and Structures Named Constants Uninitialization Reason Codes

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Uninitialization Reason Codes

Uninitialization reason codes are returned by the UninitializeReason() function. The possible values are the following:

Constant

Value

Description

REASON_PROGRAM

0

Expert Advisor terminated its operation by calling the ExpertRemove() function

REASON_REMOVE

1

Program has been deleted from the chart

REASON_RECOMPILE

2

Program has been recompiled

REASON_CHARTCHANGE

3

Symbol or chart period has been changed

REASON_CHARTCLOSE

4

Chart has been closed

REASON_PARAMETERS

5

Input parameters have been changed by a user

REASON_ACCOUNT

6

Another account has been activated or reconnection to the trade server has occurred due to changes in the account settings

REASON_TEMPLATE

7

A new template has been applied

REASON_INITFAILED

8

This value means that OnInit() handler has returned a nonzero value

REASON_CLOSE

9

Terminal has been closed

The uninitialization reason code is also passed as a parameter of the predetermined function OnDeinit(const int reason).

The codes 1(REASON_REMOVE) and 2(REASON_RECOMPILE) are implemented for the indicators.

Example:

//+------------------------------------------------------------------+
//| get text description                                             |
//+------------------------------------------------------------------+
string getUninitReasonText(int reasonCode)
  {
   string text="";
//---
   switch(reasonCode)
     {
      case REASON_ACCOUNT:
         text="Account was changed";break;
      case REASON_CHARTCHANGE:
         text="Symbol or timeframe was changed";break;
      case REASON_CHARTCLOSE:
         text="Chart was closed";break;
      case REASON_PARAMETERS:
         text="Input-parameter was changed";break;
      case REASON_RECOMPILE:
         text="Program "+__FILE__+" was recompiled";break;
      case REASON_REMOVE:
         text="Program "+__FILE__+" was removed from chart";break;
      case REASON_TEMPLATE:
         text="New template was applied to chart";break;
      default:text="Another reason";
     }
//---
   return text;
  }
//+------------------------------------------------------------------+
//| Expert deinitialization function                                 |
//+------------------------------------------------------------------+
void OnDeinit(const int reason)
  {
//--- The first way to get the uninitialization reason code
   Print(__FUNCTION__,"_Uninitalization reason code = ",reason);
//--- The second way to get the uninitialization reason code
   Print(__FUNCTION__,"_UninitReason = ",getUninitReasonText(_UninitReason));
  }