WPF Tabcontrol绑定

如何解决WPF Tabcontrol绑定

有我的密码

     <TabControl x:Name="TabControlsql" Margin="10,10,10" Grid.Row="2" SelectionChanged="TabControlsql_SelectionChanged" ItemsSource="{Binding}">
            <TabControl.Resources>
                <DataTemplate x:Key="TabHeader" DataType="TabItem">
                    <Grid>
                        <Grid.ColumnDeFinitions>
                            <ColumnDeFinition></ColumnDeFinition>
                            <ColumnDeFinition></ColumnDeFinition>
                            <ColumnDeFinition></ColumnDeFinition>
                            <ColumnDeFinition></ColumnDeFinition>
                            <ColumnDeFinition></ColumnDeFinition>
                            <ColumnDeFinition></ColumnDeFinition>
                            <ColumnDeFinition></ColumnDeFinition>
                            <ColumnDeFinition></ColumnDeFinition>
                        </Grid.ColumnDeFinitions>
                        <TextBlock Text="{Binding SourceImageTab}" FontSize="20" Foreground="Red"></TextBlock>//binding not work
                        <TextBlock Grid.Column="0" Text="[" />
                        <TextBlock Grid.Column="1" Text="{Binding RelativeSource={RelativeSource AncestorType=TabItem },Path=Header}" />
                        <TextBlock Grid.Column="2" Text="]" />
                        <Button Background="Transparent" BorderBrush="Transparent" Grid.Column="2" Height="15" Width="15" Padding="0" Name="btnUnLock" Click="btnUnLock_Click" Margin="10,0">
                            <Image HorizontalAlignment="Center" VerticalAlignment="Center" Source="{Binding SourceImageTab}" Height="12" ></Image>//binding not work
                        </Button>
                        <Button Background="Transparent" BorderBrush="Transparent" Grid.Column="3" Height="15" Width="15" Name="btnDelete" Padding="0"  Margin="3,0" Click="btnDelete_Click" CommandParameter="{Binding RelativeSource={RelativeSource AncestorType={x:Type TabItem}},Path=Name}">
                            <Image HorizontalAlignment="Center" VerticalAlignment="Center" Source="..//Resources/cancel.png" Height="12" ></Image>
                        </Button>
                    </Grid>
                </DataTemplate>
            </TabControl.Resources>
        </TabControl>
        <TextBlock Text="{Binding SourceImageTab}" FontSize="20" Foreground="Red"></TextBlock>//this work

为什么只有一个绑定有效？第一和第二个不，为什么？也许问题是tabcontrol绑定？我还添加了Window.Inizialized {DataContext = this}，谢谢

这是财产

public string SourceImageTab
    {
        get
        {
            return "..//Resources/locked.png";
        }
    }

解决方法

您正在使用两个不同的范围：MainWindow的范围和DataTemplate的范围。

两个作用域都有不同的DataContext值： 由于您已将MainWindow.DataContext设置为this，因此MainWindow.DataContext就是MainWindow本身。
DataTemplate.DataContext始终是目标数据项，在您的情况下，它就是当前的TabItem。

由于SourceImageTab是在MainWindow上定义的，因此MainWIndow范围内的绑定有效。绑定Binding SourceImageTab解析为MainWindow.SourceImageTab属性。但是在DataTemplate内部，相同的绑定表达式解析为TabIte.SourceImageTab，该表达式不存在。

解决方案是调整DataTemplate内部的绑定。为了找到MainWindow，您可以使用Binding.RelativeSource。而且，当前具有TabItem作为源的绑定也可以简化为例如。 `{Binding Header}“：

MainWindow.xaml.cs

// TODO::Create a binding source collection which binds to the TabControl
partial class MainWindow : Window
{
  public ObservableCollection<MyTabDataItem> TabItems { get; set; }
  public MainWindow()
  {
    InitializeComponent();
    this.DataContext = this;
  }
}

MainWindow.xaml

<TabControl x:Name="TabControlSQL" ItemsSource="{Binding MyTabDataItem}">
  <TabControl.Resources>
    <DataTemplate x:Key="TabHeader" DataType="TabItem">
      <Grid>
        <Grid.ColumnDefinitions>
          ...
        </Grid.ColumnDefinitions>
        
        <TextBlock Text="{Binding RelativeSource={RelativeSource AncestorType=Window},Path=SourceImageTab}" FontSize="20" Foreground="Red" /> //binding now works

        ...           

        <TextBlock Grid.Column="1" Text="{Binding Header}" />

        ...

        <Button>
          <Image Source="{Binding RelativeSource={RelativeSource AncestorType=Window},Path=SourceImageTab}" /> //binding now works
        </Button>
        ...
        <Button CommandParameter="{Binding Name}">
          <Image HorizontalAlignment="Center" VerticalAlignment="Center" Source="..//Resources/cancel.png" Height="12"  />
        </Button>
      </Grid>
    </DataTemplate>
  </TabControl.Resources>
</TabControl>

<TextBlock Text="{Binding SourceImageTab}" FontSize="20" Foreground="Red" /> // this worked before