The TBN_ENDDRAG notification message notifies the toolbar’s parent window that
the user has stopped dragging a button in a toolbar. This message is sent in
the form of a WM_NOTIFY message.
TBN_ENDDRAG
ptbn = (TBNOTIFY FAR *) lParam;
Parameters
ptbn
Pointer to a TBNOTIFY structure. The iItem member contains the
zero-based index of the button being dragged.