WPF组合框Mvvm绑定

Question

我正在尝试从列表中选择值到命令。有没有简单的方法将commandparameter绑定到选定的项目？

<ComboBox HorizontalAlignment="Left" Margin="-56,10,0,0" VerticalAlignment="Top" Width="120" SelectedIndex="0" ItemsSource="{Binding Time}"> 
     <i:Interaction.Triggers> 
      <i:EventTrigger EventName="Loaded"> 
       <i:InvokeCommandAction Command="{Binding TestCommand}" CommandParameter="{Binding }"></i:InvokeCommandAction> 
      </i:EventTrigger> 
      <i:EventTrigger EventName="SelectionChanged"> 
       <i:InvokeCommandAction Command="{Binding TestCommand}" CommandParameter="{Binding }"></i:InvokeCommandAction> 
      </i:EventTrigger> 
     </i:Interaction.Triggers> 
    </ComboBox> 

，当我试图像

   <i:EventTrigger EventName="SelectionChanged"> 
       <i:InvokeCommandAction Command="{Binding TestCommand}" CommandParameter="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ComboBox}},Path=SelectionBoxItem}"></i:InvokeCommandAction> 
      </i:EventTrigger> 

真奇怪卡住为什么呢？

Answer 1

<ComboBox x:Name="Combo" HorizontalAlignment="Left" Margin="-56,10,0,0" VerticalAlignment="Top" Width="120" SelectedIndex="0" ItemsSource="{Binding Time}"> 
     <i:Interaction.Triggers> 
      <i:EventTrigger EventName="Loaded"> 
       <i:InvokeCommandAction Command="{Binding TestCommand}" CommandParameter="{Binding ElementName=Combo, Path=SelectedItem}"></i:InvokeCommandAction> 
      </i:EventTrigger> 
      <i:EventTrigger EventName="SelectionChanged"> 
       <i:InvokeCommandAction Command="{Binding TestCommand}" CommandParameter="{Binding }"></i:InvokeCommandAction> 
      </i:EventTrigger> 
     </i:Interaction.Triggers> 
    </ComboBox> 

如果你给你的组合框的名称，你可以使用ElementName绑定和绑定到Path SelectedItem