如何设计内容变动的ContextMenu?

Question

我有一个TreeView，在TreeViewItem 设置了ContextMenu

 <TreeView Name="treeViewAp">


  <TreeViewItem Header="A">



  <TreeViewItem Header="1" Foreground="White" />



  <TreeViewItem Header="2" Foreground="White" />



  </TreeViewItem>



  <TreeViewItem Header="B" >



  <TreeViewItem Header="3" Foreground="White" />



  <TreeViewItem Header="4" Foreground="White" />



  </TreeViewItem>



  <TreeViewItem Header="C">



  <TreeViewItem Header="5" Foreground="White" />



  <TreeViewItem Header="6" Foreground="White" />



  </TreeViewItem>







 </TreeView>

我希望能把Header=1的item转移到C，这时ContextMenu就会显示转移到B或C,但是TreeView的Item是不固定的，用户可以随意新增TreeViewItem和修改TreeViewItem的Header。

这样就导致我的ContextMenu里的Item也要随着TreeViewItem数量减一变动,而且Header也要随着TreeViewItem变动。更重要的是每个TreeViewItem都拥有这个ContextMenu。。     请问这个ContextMenu如何设计？

Answer 1

你好，

我写了个简单的小例子，希望能提供一些思路。

    <TreeView Name="treeViewAp" Tag="TV">
      <TreeView.ContextMenu>
        <ContextMenu ItemsSource="{Binding RelativeSource={RelativeSource Self}, Path=PlacementTarget.Items}">
          <ContextMenu.ItemTemplate>
            <DataTemplate>
              <TextBlock>转移到<TextBlock Text="{Binding Header}"/></TextBlock>
            </DataTemplate>
          </ContextMenu.ItemTemplate>
          <ContextMenu.ItemContainerStyle>
            <Style TargetType="MenuItem">
              <EventSetter Event="Click" Handler="MenuItem_Click"/>
              <Setter Property="Tag" Value="{Binding RelativeSource={RelativeSource AncestorType=ContextMenu}, Path=PlacementTarget.SelectedItem}"/>
            </Style>
          </ContextMenu.ItemContainerStyle>
        </ContextMenu>
      </TreeView.ContextMenu>
      <TreeViewItem Header="A" Tag="A">
        <TreeViewItem Header="1" Foreground="White" Tag="1"/>
        <TreeViewItem Header="2" Foreground="White" />
      </TreeViewItem>
      <TreeViewItem Header="B" >
        <TreeViewItem Header="3" Foreground="White" />
        <TreeViewItem Header="4" Foreground="White" />
      </TreeViewItem>
      <TreeViewItem Header="C">
        <TreeViewItem Header="5" Foreground="White" />
        <TreeViewItem Header="6" Foreground="White" />
      </TreeViewItem>
    </TreeView>

 

    private void MenuItem_Click(object sender, RoutedEventArgs e)
    {
      MenuItem menuItem = (MenuItem)sender;
      TreeViewItem selectedItem = menuItem.Tag as TreeViewItem;
      if (selectedItem != null)
      {
        TreeViewItem targetItem = menuItem.DataContext as TreeViewItem;
        ItemsControl originalParent = ItemsControl.ItemsControlFromItemContainer(selectedItem);
        if (targetItem !=null && originalParent !=null )
        {
          originalParent.Items.Remove(selectedItem);
          targetItem.Items.Add(selectedItem);
        }
      }
    }

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Min Zhu [MSFT]
MSDN Community Support | Feedback to us
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Answer 2

右键菜单内容不能固定，当点击A时效果是转移至B或C，就不能在出现A了。

Answer 3

前面的代码仅仅只能提供一个思路，在细节方面需要根据你的具体需要进行调整。

要做到点击A时不出现A，可以通过ContextMenu的ItemContainerStyle把MenuItem的IsVisible属性多重绑定到SelectedItem和Items上进行判断。

---

Min Zhu [MSFT]
MSDN Community Support | Feedback to us
Get or Request Code Sample from Microsoft
Please remember to mark the replies as answers if they help and unmark them if they provide no help.