WindowProc

  LRESULT CALLBACK WindowProc(hwnd, wMsg, wParam, lParam)    
  HWND hwnd;    
  UINT wMsg;    
  WPARAM wParam;    
  LPARAM lParam;    

The WindowProc function is an application-defined callback function that processes messages sent to a window.

Parameters

hwnd

Identifies the window.

wMsg

Specifies the message.

wParam

Specifies additional message information. The contents of this parameter depend on the message being sent.

lParam

Specifies additional message information. The contents of this parameter depend on the message being sent.

Return Value

The callback function should return the result of the message processing. The actual return values depends on the message that is processed.

Comments

WindowProc is a placeholder for the application-supplied function name. The actual name must be exported by including it in an EXPORTS statement in the application's module-definition file.

See Also

DefWindowProc, RegisterClass