public void DeleteMultiDrawingItem(AbstractMultiDrawing manager, Guid itemId) { ITrackable item = manager.GetItem(itemId) as ITrackable; if (item != null) { DeleteTrackableDrawing(item); } manager.Remove(itemId); UnselectAll(); if (MultiDrawingItemDeleted != null) { MultiDrawingItemDeleted(this, EventArgs.Empty); } }