A docked toolbar is a child of the frame window it's docked to, but a floating toolbar is a child of the mini frame window that surrounds it. The mini frame window is a popup window owned by the frame window, but it's not a child of the frame window. (A popup window is a window with the style WS_POPUP; a child window has the WS_CHILD style instead.) The distinction is important because popup windows owned by a frame window are destroyed before the frame window is destroyed. Child windows, on the other hand, are destroyed after their parents are destroyed. A floating toolbar no longer exists when the frame window's OnDestroy function is called.

评论