private void Dungeon_DragDrop(object sender, DragEventArgs e) { if (e.Data.GetData(typeof(Room)) != null) { Room room = (Room)e.Data.GetData(typeof(Room)); room.Dispose(); } if (e.Data.GetData(typeof(Entrance)) != null) { Entrance entrance = (Entrance)e.Data.GetData(typeof(Entrance)); entrance.Dispose(); } }