Question

我有ListView DataTemplate，在此模板中有几个文本块和一个按钮。该按钮具有带固定项目的上下文菜单。 listviewitems的绑定工作正常，但将属性绑定到contextmenu似乎不起作用。

<ListView x:Name="lv_clients" Margin="0 22 0 0" SelectionMode="Single">
    <ListView.ItemTemplate>
        <DataTemplate>
            <Grid>
                <Grid Grid.Column="0" Grid.RowSpan="2" Background="{Binding StateColor}">
                </Grid>
                <TextBlock Grid.Column="1" Text="{Binding DisplayString}" Foreground="Black" Height="20" FontWeight="Bold" Padding="2,2,0,0" />
                <Button Click="Button_ListItem_Click" Grid.Column="1" Grid.Row="0" HorizontalAlignment="Right" VerticalAlignment="Top">
                    <Button.ContextMenu>
                        <ContextMenu>
                            <MenuItem Header="Anrufen" Name="mn_call" Click="mn_call_Click" DataContext={Binding Number} />
                        </ContextMenu>
                    </Button.ContextMenu> ...</Button>
                <StackPanel Grid.Column="1" Grid.Row="1">
                    <TextBlock Text="{Binding State}" Height="20" Padding="2,2,0,0"/>
                    <StackPanel Orientation="Horizontal">
                        <TextBlock Text="{Binding FirstEntry.KDKGRS}" Height="20" FontWeight="Bold" Padding="2,2,2,0" HorizontalAlignment="Left" Foreground="{Binding FirstEntry.ConvertedKGFARBE}" />
                        <TextBlock Text="{Binding FirstEntry.ADNAMI}" Height="20" Padding="0,2,0,0" HorizontalAlignment="Left" />
                    </StackPanel>
                </StackPanel>
            </Grid>
        </DataTemplate>
    </ListView.ItemTemplate>
</ListView>

为了便于阅读，我删除了一些不必要的代码（样式和列定义）。

重要的部分是MenuItem内的Button。我的基础类有一个公共字符串属性Number。这应该传递给菜单项。但是DataContext的{{1}}在click事件中始终为null。

我已经读过一些关于上下文的内容，而不是视觉树的一部分，但我无法绕过它。有人可以用绑定来解释这个问题吗？

编辑基础类的代码： 再次删除了一些不必要的问题代码

MenuItem

ListBox的绑定：

public class PhoneClient
{
    public String Name { get; set; }
    public String Number { get; set; }
    public String Extension { get; set; }
    public String DisplayString
    {
        get
        {
            return String.IsNullOrEmpty(Name) ? Number : String.Format("{0} ({1})", Name, Extension);
        }
    }
}

Answer 1

缩小差距

<ContextMenu Tag="{Binding PlacementTarget.DataContext, RelativeSource={RelativeSource Self}}">
    <MenuItem Header="Anrufen" Click="mn_call_Click" Name="mn_call" 
              DataContext="{Binding Tag.Number, RelativeSource={RelativeSource AncestorType={x:Type ContextMenu}}}" />
</ContextMenu>

处理程序

private void mn_call_Click(object sender, RoutedEventArgs e)
{
    MenuItem currentMenuItem = (MenuItem)sender;
    string number = (string)currentMenuItem.DataContext;
    // Do Stuff
}

修改

<强> MainWindow.xaml

<Window x:Class="WpfApp.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="MainWindow" Height="350" Width="525"> <Grid Margin="10"> <ListView x:Name="lv_clients" Margin="0 22 0 0" SelectionMode="Single"> <ListView.ItemTemplate> <DataTemplate> <Grid Background="LightGray" Width="100"> <Grid.RowDefinitions> <RowDefinition/> <RowDefinition/> </Grid.RowDefinitions> <Grid Background="LightGreen"> </Grid> <TextBlock Text="{Binding DisplayString}" Foreground="Black" Height="20" FontWeight="Bold" Padding="2,2,0,0" /> <Button Click="Button_ListItem_Click" Grid.Row="0" HorizontalAlignment="Right" VerticalAlignment="Top"> <Button.ContextMenu> <ContextMenu Tag="{Binding PlacementTarget.DataContext, RelativeSource={RelativeSource Self}}"> <MenuItem Header="Show" Click="mn_call_Click" Name="mn_call" DataContext="{Binding Tag.Number, RelativeSource={RelativeSource AncestorType={x:Type ContextMenu}}}" /> </ContextMenu> </Button.ContextMenu> ... </Button> <StackPanel Grid.Row="1"> <TextBlock Text="{Binding State}" Height="20" Padding="2,2,0,0"/> <StackPanel Orientation="Horizontal"> <TextBlock Text="Foo" Height="20" FontWeight="Bold" Padding="2,2,2,0" HorizontalAlignment="Left" Foreground="Blue" /> <TextBlock Text="Bar" Height="20" Padding="0,2,0,0" HorizontalAlignment="Left" /> </StackPanel> </StackPanel> </Grid> </DataTemplate> </ListView.ItemTemplate> </ListView> </Grid> </Window>

<强> MainWindow.xaml.cs

using System; using System.Windows; using System.Windows.Controls; using System.Collections.Generic; namespace WpfApp { public partial class MainWindow : Window { public MainWindow() { InitializeComponent(); List<PhoneClient> clients = new List<PhoneClient>(); clients.Add(new PhoneClient() { Name = "Kumar", Number = "0101010", Extension = "555", State = "New York" }); clients.Add(new PhoneClient() { Name = "Shanaya", Number = "1010101", Extension = "555", State = "New Jersey" }); clients.Add(new PhoneClient() { Name = "Billy Bob", Number = "6543210", Extension = "555", State = "Single" }); lv_clients.ItemsSource = clients; } public class PhoneClient { public String Name { get; set; } public String Number { get; set; } public String Extension { get; set; } public String State { get; set; } public String DisplayString { get { return String.IsNullOrEmpty(Name) ? Number : String.Format("{0} ({1})", Name, Extension); } } } private void mn_call_Click(object sender, RoutedEventArgs e) { MenuItem currentMenuItem = (MenuItem)sender; string number = (string)currentMenuItem.DataContext; MessageBox.Show("Number " + number); } private void Button_ListItem_Click(object sender, RoutedEventArgs e) { Button currentButton = (Button)sender; PhoneClient data = (PhoneClient)currentButton.DataContext; MessageBox.Show(data.Name + " tapped"); } } }

Menuview中的MenuItem绑定datacontext

1 个答案: