The DefWindowProc function calls the default window procedure to provide default processing for any window messages that an application does not process. This function ensures that every message is processed. DefWindowProc is called with the same parameters received by the window procedure.
LRESULT DefWindowProc(
HWND hWnd, // handle to window
UINT Msg, // message identifier
WPARAM wParam, // first message parameter
LPARAM lParam // second message parameter
);
The return value is the result of the message processing and depends on the message.
Windows CE: If Msg is WM_SETTEXT, zero is returned.
DefWindowProc does not automatically call PostQuitMessage when it handles a WM_DESTROY message.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Requires version 1.0 or later.
Header: Declared in winuser.h.
Import Library: Use user32.lib.
Unicode: Implemented as Unicode and ANSI versions on Windows NT.
Window Procedures Overview, Window Procedure Functions, CallWindowProc, DefDlgProc, WindowProc