+DestroyWnd is an overridden method in +TScrollingWinControl used to maintain resources allocated in the +class instance when the window Handle for the control is freed. It calls the +inherited method on entry to free handles allocated for the control Canvas and +the widgetset class instance. It ensures that scroll bar information allocated +in either HorzScrollBar or VertScrollBar is invalidated when the handle(s) are +freed. +
+