#define's for known commands that can be used for PostMessageA()

[Deleted] 2010.03.19 14:25

I thought this might be helpful. I found the original somewhere on the net and expanded on it.

It should be noted that many of these commands should not be used because the MQL4 language provides better, cleaner, alternatives. Occasionally though, you find you need to accomplish a particular task and there is just no other way.

A good example would be that you need to write an EA, because you want it to stay on the chart when timeframe or symbol are changed, but you also want it to remove itself from the chart (like a script does) once a certain task is done. In this case, the EA could send a message to its chart window to have itself removed.

There are two attachments
- aswincmd.mqh contains the numeric codes and mostly defines for those commands I could find out about so far.
- cmd.mq4 is a script that will, potentially, let you find more commands by simply trying out all possible commands in a loop.

Files:

aswincmd.mqh 10 kb

cmd.mq4 1 kb

gordon 2010.03.20 01:07 #1

This is indeed the first time I have seen all this in one file. Thanks.

William Roeder 2010.09.29 14:52 #2

https://www.mql5.com/en/forum/128554

#include <WinUser32.mqh>
#import "user32.dll"
  int GetForegroundWindow();
#import
void PauseTest(){
        if (IsTesting() && IsVisualMode()){
                int hmain = GetForegroundWindow();
                PostMessageA(hmain, WM_COMMAND, 0x57a, 0);      }       // 1402
}

#define MT4_WMCMD_UPDATE_DATA 33324 /* This doesn't cause experts start() to run */

This comment conflicts with the Period Converter/range bars

   if(hwnd == 0) {
      //trying to detect the chart window for updating
      hwnd = WindowHandle(Symbol(), NewPeriod);
   }
   if(hwnd!= 0) {
      if (IsDllsAllowed() == false) {
         //DLL calls must be allowed
         DebugMsg("Dll calls must be allowed");
         return (-1);
      }
      if (PostMessageA(hwnd,WM_COMMAND,0x33324,0) == 0) {
         //PostMessage failed, chart window closed
         hwnd = 0;
      } else {
         //PostMessage succeed
         return (0);
      }
   }

William Roeder 2011.07.23 18:43 #3

In the above don't want forgroundWindow. Also it takes sometime before the GUI reacts. Update:

#include <WinUser32.mqh>
#import "user32.dll"
  int GetAncestor(int, int);
#import
void PauseTest(){   datetime now = TimeCurrent();   static datetime oncePerTick;
    if (IsTesting() && IsVisualMode() && IsDllsAllowed() && oncePerTick != now){
        oncePerTick = now;
        for(int i=0; i<200000; i++){        // Delay required for speed=32 (max)
            int main = GetAncestor(WindowHandle(Symbol(), Period()), 2/*GA_ROOT*/);
            if (i==0) PostMessageA(main, WM_COMMAND, 0x57a, 0); // 1402. Pause
    }   }
}