private void DataGrid_RowEditEnding(object sender, DataGridRowEditEndingEventArgs e)
        {
            DinerMax3000.Business.MenuItem newMenuItem = e.Row.Item as DinerMax3000.Business.MenuItem;

            if (newMenuItem != null && e.EditAction == DataGridEditAction.Commit && e.Row.IsNewItem)
            {
                DinerMax3000ViewModel currentViewModel = (DinerMax3000ViewModel)DataContext;
                currentViewModel.NewMenuItems.Add(newMenuItem);
            }
        }
        private void Button_Click(object sender, RoutedEventArgs e)
        {
            DinerMax3000ViewModel currentViewModel = (DinerMax3000ViewModel)DataContext;

            foreach (var currentMenuItem in currentViewModel.NewMenuItems)
            {
                currentViewModel.SelectedMenu.SaveNewMenuItem(currentMenuItem.Title, currentMenuItem.Description, currentMenuItem.Price);
            }

            BindingOperations.GetBindingExpressionBase(cboAllMenus, ComboBox.ItemsSourceProperty).UpdateTarget();
        }