PeekMessage for Parent Window

[Craig Longman]

I'm writing a plug-in for a product that provides extremely little (ie. none) feedback about the window environment. Even something as simple as a resize event is not delivered. So, I'm trying to hook into the parent window(s) to catch messages that they receive and process them appropriately. To that end, I've created a simple class that looks something like this:

CSizeWatcher::operator()( HWND hWnd )
{
MSG zMsg;

while( true )
{
if( ::PeekMessage( &zMsg, hWnd, WM_SIZE, WM_SIZE, PM_NOREMOVE ) )
{
if( zMsg.message == WM_QUIT )
{
break;
}

  if( zMsg.message == WM\_SIZE )
  {
    printf( "oh..." );
  }
}

}
}

And it gets invoked from the OnInitDialog method like this (effectively, it is actually instantiated in a separate thread):

zWatcher( ::GetParent( m_hWnd ) );

Using Spy++, I see that I do have the correct HWND, but I never seem to get any messages. PeekMessage never returns true. I have tried removing the Min and Max, setting both to zero, but again, no messages. Is this an inappropriate use of PeekMessage? Can one not use it to peek into the queues for parent (or any) windows? Perhaps Hooks are what I need to look at? Thanks, CraigL

[Craig Longman]

Well, absolutely no luck getting the PeekMessage to work, so I've instead gone and sub-classed the window. Although it's far more tricky from c++, it does get what I need.

[Stephen Hewitt]

GetMessage[^] and PeekMessage[^] use the message queue: they will only work for messages that were posted (see PostMessage[^]). The WM_SIZE[^] message is sent (see SendMessage[^]). Subclassing or hooking (See SetWindowsHookEx[^]) is the way to go.

Steve