WM_NCDESTROY top-level constant
Notifies a window that its nonclient area is being destroyed. The DestroyWindow function sends the WM_NCDESTROY message to the window following the WM_DESTROY message.WM_DESTROY is used to free the allocated memory object associated with the window.
The WM_NCDESTROY message is sent after the child windows have been destroyed. In contrast, WM_DESTROY is sent before the child windows are destroyed.
const WM_NCDESTROY = 0x0082;