Question

I created win32 wrapper before but I lost the files… So I’m gonna creating them again. The problem is with my router(static window processor).
Here is my code

CFramework *wnd = 0; 

// retrieve associated Window instance 
wnd = reinterpret_cast<CFramework *>(::GetWindowLongPtr(hWnd, GWL_USERDATA)); 

// call the windows message handler 
wnd->WndProc(hWnd, msg, wParam, lParam);

return true;

When I call GetWindowLongPtr it won’t retrieves the user data.
UPDATE:
I also tired this code that uses SetWindowLongPtr

if ( msg == WM_CREATE ) 
   { 
       SetWindowLongPtr( hWnd, GWLP_USERDATA, (LONG)((CREATESTRUCT *)lParam)->lpCreateParams ); 
   } 

   Window *targetApp = (Window*)GetWindowLongPtr( hWnd, GWLP_USERDATA ); 

   if ( targetApp ) 
   { 
       return targetApp->WndProc( hWnd, msg, wParam, lParam ); 
   } 

   return DefWindowProc( hWnd, msg, wParam, lParam ); 

I used my second code.^^^^
I put break point at SetWindow…
It seems it never Get called!

Answer 1

Your window may receive some messages before WM_CREATE. I did something like this a while ago, and there were sizing and positioning messages, along with WM_NCCREATE, that arrived before the WM_CREATE. So you shouldn’t expect to see the value there on those messages.

Are you compiling for 32-bit or 64-bit? If 64-bit, then the cast to LONG may be whacking your pointer.

And, as Rup said in the comments, you have to be really certain that nobody else is using WM_USERDATA.