如何在每个按钮单击事件后添加新项目并将以前的项目保留在通用列表中？

debugcn 发表于 Dev

蓝条

我想在用户单击按钮时将新项目添加到我的通用列表中，但是当我单击按钮时，我看到列表只包含最后引入的项目。似乎在每个按钮单击列表期间都被重新初始化。如何保留旧项目并将新项目添加到通用列表中并在列表框中显示所有项目？

谢谢..

C#代码

namespace Example
{
   /// <summary>
   /// Interaction logic for CreateProduct.xaml
   /// </summary>
   public partial class CreateProduct : Window
   {
       public static float weight;
       public static int quantity;
       public static string customer, piece, material;

       public CreateProduct()
       {
            InitializeComponent();

       }

       public static List<Liste> AddList()
       {
            List<Liste> list = new List<Liste>();
            Liste kayit= new Liste();

            kayit.Customer = customer;
            kayit.Piece = piece;
            kayit.Material = material;
            kayit.Quantity = quantity;
            kayit.Weight = weight;

            list.Add(kayit);

            return list;        
       }

       private void btnAdd_Click(object sender, RoutedEventArgs e)
       {
            customer = btnEditCustomer1.Text;
            piece = btnPiece.Text;
            material = txtMaterial.Text;
            quantity = Convert.ToInt32(txtQuantity.Text);
            weight = float.Parse(txtWeight.Text);

            if (customer != null && piece != null && material != null)
            {
                listBoxProduct.ItemsSource = AddList();
            }
        }
    }

    public class Liste
    {
        public string Customer { get; set; }
        public string Piece { get; set; }
        public string Material { get; set; }
        public int Quantity { get; set; }
        public float Weight { get; set; }
    }    
}

XAML 代码

<ListBox Grid.Row="1" x:Name="listBoxProduct"  SelectionMode="Single"   Margin="0" Background="Transparent" ScrollViewer.VerticalScrollBarVisibility="Auto"  ScrollViewer.HorizontalScrollBarVisibility="Hidden" Height="200">
    <ListBox.ItemTemplate>
        <DataTemplate>
            <Border BorderThickness="1" Margin="0" Height="30" CornerRadius="4" Width="875"  Background="#2E323B" BorderBrush="Black">
                <DockPanel>
                    <TextBlock Text="{Binding Customer}"  Foreground="White" TextWrapping="Wrap"  VerticalAlignment="Stretch" FontSize="16"  HorizontalAlignment="Left" Margin="4,0,0,0"/>
                    <TextBlock Text="{Binding Piece}"    Foreground="White"  TextWrapping="Wrap" VerticalAlignment="Stretch" FontSize="16"  HorizontalAlignment="Left" Margin="4,0,0,0"/>
                    <TextBlock Text="{Binding Material}"  Foreground="White"  TextWrapping="Wrap" VerticalAlignment="Stretch" FontSize="16"  HorizontalAlignment="Left" Margin="4,0,0,0"/>
                    <TextBlock Text="{Binding Quantity}"  Foreground="White"  TextWrapping="Wrap" VerticalAlignment="Stretch" FontSize="16"  HorizontalAlignment="Left" Margin="4,0,0,0"/>
                    <TextBlock Text="{Binding Weight}"  Foreground="White"  TextWrapping="Wrap" VerticalAlignment="Stretch" FontSize="16"  HorizontalAlignment="Left" Margin="4,0,0,0"/>
                </DockPanel>
            </Border>
        </DataTemplate>
    </ListBox.ItemTemplate>
</ListBox>

灰

修复您的代码的一些问题：

static尽可能避免
不要在每次点击时创建一个新的 List 实例，你会丢失以前的项目。在窗口中声明一个字段。
listBox 需要知道何时添加新项目以显示它们。但 List 不报告有关添加/删除的信息。用ObservableCollection

public partial class CreateProduct : Window
{
    private ObservableCollection<Liste> list = new ObservableCollection<Liste>();    

    public CreateProduct()
    {
        InitializeComponent();
        listBoxProduct.ItemsSource = list;
    }

    private void btnAdd_Click(object sender, RoutedEventArgs e)
    {
       float weight;
       int quantity;
       string customer, piece, material;

       customer = btnEditCustomer1.Text;
       piece = btnPiece.Text;
       material = txtMaterial.Text;
       quantity = Convert.ToInt32(txtQuantity.Text);
       weight = float.Parse(txtWeight.Text);

       if (customer != null && piece != null && material != null)
       {
          Liste kayit = new Liste();

          kayit.Customer = customer;
          kayit.Piece = piece;
          kayit.Material = material;
          kayit.Quantity = quantity;
          kayit.Weight = weight;

          list.Add(kayit);
       }
    }
}

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