The destroy window hook is called whenever a window is destroyed. The following code shows the syntax for a destroy window hook function:

BOOL EXPENTRY DestroyWindowHook (HAB   hab,
                                 HWND  hwnd,
                                 ULONG ulReserved);

This hook is sent after the WM_DESTROY message has been sent and just before the window becomes invalid.

The hab parameter is the anchor block handle.

The hwnd parameter is the handle of the window being destroyed.

The ulReserved parameter is reserved.

When this hook function returns TRUE, the function completed successfully.

When it returns FALSE, an error occurred.