Subj : Unregistered HWND_BROADCAST messages
To   : borland.public.cpp.borlandcpp
From : Alexandre Sá
Date : Wed Jun 29 2005 11:19 am

(sorry if I sent this email widely)
Hi there, the problem I found is:
  The unregistered broadcast messages works "fine" on BC++
  and doesn´t work on BCB6 and VC++.

I´m trying to migrate an old BC++ 4.5 project to the BCB6.
After the migration to BCB6, the unregistered broadcast
messages didn´t work any more.

But can someone say why it works like that?
Think I need to understand it to be able to
solve the problem I have.

I put here a fully functional piece of code that reproduce
a different behavior on such compilers.

Does BC++ 4.5 use a different Windows API (3.1?) to compiler this code?
(even if I create a Win32 project)?

Any help?

Best regards,
Alexandre Sá

PS.:
You know that it´s better register broadcast messages
(RegisterWindowMessage), you know that this code
is not a good programming practice, etc.
But the project was entirely made to use unregistered broadcast
messages and any change may lead to a complete refactoring.

//----------------------------­­-----------------------------­-­------------
//---------------------------­­------------------------------­­-------------
//This code creates a window class (WNDCLASS), register the
//class (RegisterClass), creates a window instance (CreateWindow),
//sends a (user defined and unregistered) broadcast message and tries to
//peek this message (PeekMessage). On BC++, the message is peeked, and on
the
//BCB6 (or VC++) it´s not peeked.

#include <windows.h>

//---------------------------­­------------------------------­­-------------
static LRESULT WndProc (HWND hWnd, UINT msg,
                        WPARAM wParam, LPARAM lParam) {
  return (DefWindowProc(hWnd,msg,wParam­­,lParam));
}

//------------------------­---­---------------------------­--­--------------
#pragma argsused
WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
               LPSTR lpCmdLine, int nCmdShow)
{
  WNDCLASS windowClass = {0};

  windowClass.style         = CS_HREDRAW | CS_VREDRAW | CS_OWNDC ;
  windowClass.lpfnWndProc   = (WNDPROC)WndProc;
  windowClass.cbClsExtra    = 0;
  windowClass.cbWndExtra    = 0;
  windowClass.hInstance     = hInstance ;
  windowClass.hbrBackground = (HBRUSH)(GetStockObject(BLACK_­­BRUSH));
  windowClass.lpszMenuName  = NULL;
  windowClass.lpszClassName = "TMyForm";

  RegisterClass(&windowClass);

  HWND hWindow = CreateWindow (
    "TMyForm", "MyForm", WS_POPUPWINDOW,
    10, 10, 200, 200,
    NULL, NULL,
    hInstance, NULL);

  PostMessage(HWND_BROADCAST, WM_USER+2, 0, 0L);
  MSG m;
  while(PeekMessage (&m, NULL, 0, 0, PM_NOREMOVE)) {
    if(m.message == (WM_USER+2)) {
      MessageBox(NULL, "Work!", "", MB_OK);
    }
  }

  MessageBox(NULL, "end", "", MB_OK);
  return 0;



}

//---------------------------­­------------------------------­­-------------
//---------------------------­­------------------------------­­-------------

.