/// <summary> /// to add lemon oo the order item /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void AddLemon_Click(object sender, RoutedEventArgs e) { if (tea) { if (DataContext is Order order) { if (CollectionViewSource.GetDefaultView(order.Items).CurrentItem is Drink drink) { if (drink is Tyrannotea tea) { tea.AddLemon(); } else if (drink is Water water) { water.AddLemon(); } } } tea = false; } }