The LVN_DELETEALLITEMS notification message notifies a list view control’s parent window that all items in the control are about to be deleted. This notification message is sent in the form of a WM_NOTIFY message.
LVN_DELETEALLITEMS pnmv = (NM_LISTVIEW FAR *) lParam;
To suppress subsequent LVN_DELETEITEM notification messages, return TRUE.
To receive subsequent LVN_DELETEITEM notification messages, return FALSE.
A list-view control sends the LVN_DELETEALLITEMS notification message when it is destroyed or when it receives the LVM_DELETEALLITEMS message. If LVN_DELETEALLITEMS does not return TRUE, the control will also send an LVN_DELETEITEM notification message as each item is deleted.
If the LVN_DELETEALLITEMS message handler is in a dialog procedure, return TRUE from the dialog procedure, and use the SetWindowLong function with DWL_MSGRESULT to set the message return value.