Win32 subclassing

subclassing은 윈도우 메시지 프로시저로 전달되는 메시지를 중간에 가로채는 것을 말한다.

SubClassing Window Handle= hwnd;
SubClassing Destination Message Procedure= newWndProc;

1. hwnd가 생성된 후,

   oldWndProc = (WNDPROC)SetWindowLong(hwnd, GWL_WNDPROC, (LONG)newWndProc);
   

2. 종료할 때,

   SetWindowLong(hwnd, GWL_WNDPROC, (LONG)oldWndProc);
   

3. SubClassing Window Procedure

   LRESULT CALLBACK newWndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam){
    return CallWindowProc(oldWndProc, hWnd, msg, wParam, lParam);
   }