Notifies an appbar when a full-screen application is opening or closing. When a full-screen application is opening, an appbar must drop to the bottom of the Z order. When it is closing, the appbar should restore its Z order position. This notification is sent in the form of an application-defined message that is set by the ABM_NEW message.
ABN_FULLSCREENAPP fOpen = (BOOL) lParam;
No return value.