WPF UserControl上下文菜单可见性绑定

问题描述

我的用户控件上下文菜单可见性无法绑定依赖项属性。知道吗？

My user control context menu visibility can't bind a dependency property. Any idea?

这是我的WPF代码

<UserControl.ContextMenu>
    <ContextMenu Visibility="{Binding ElementName=wellControl, Path=IsInCompactMode, Converter={StaticResource BooleanToVisibilityConverter}}">
    <MenuItem Command="local:GCommands.Edit" />
    <MenuItem Command="local:GCommands.Delete" />
    <MenuItem Command="local:GCommands.ExportFcsFiles" />
    <MenuItem Command="local:GCommands.BatchExportStatistics" />
    <Separator/>
    <MenuItem Command="local:GCommands.SaveAs" Header="Save As..." />
    </ContextMenu>
</UserControl.ContextMenu>

如果我设置Visibility = Hidden，它将对我有用。
像这样：

If I set Visibility="Hidden" it will work for me.like this:

<ContextMenu Visibility="Hidden"/>

如果使用此功能将不起作用

If use this it won't work

<ContextMenu Visibility="{Binding ElementName=wellControl, Path=IsInCompactMode, Converter={StaticResource BooleanToVisibilityConverter}}">

我很确定Visibility = {Binding ElementName = wellControl，Path = IsInCompactMode，Converter = { 没有问题，因为它对其他人有用。

I'm pretty sure Visibility="{Binding ElementName=wellControl, Path=IsInCompactMode, Converter={StaticResource BooleanToVisibilityConverter}}" has not problem, cuz it works for others.

这是我的依赖项属性

public bool IsInCompactMode
        {
            get {return (bool)GetValue(IsInCompactModeProperty); }
            set {SetValue(IsInCompactModeProperty, value); }
        }
        public static readonly DependencyProperty IsInCompactModeProperty =
            DependencyProperty.Register("IsInCompactMode", typeof(bool), typeof(WellControl), new PropertyMetadata(false));

我尝试过这种方式，看来还是不行，这真的很奇怪！！！

I tried this way, it seems it still doesn't work, this is really weird!!!

<ContextMenu x:Name="menu" IsOpen="{Binding ElementName=wellControl, Path=IsInCompactMode}">

我真的很困惑，这是怎么回事？ Binding ElementName = wellControl，Path = IsInCompactMode适用于用户控件的其他部分，只是不适用于怪异的上下文菜单？

I'm really confuse about it, what's wrong? "Binding ElementName=wellControl, Path=IsInCompactMode" works for other part of the user control, just doesn't work for the weird context menu? it doesn't make sence

推荐答案

1> ContextMenu，弹出窗口，DataGridColumns都不是可视树的一部分。因此，使用 ElementName 或 RelativeSource 的绑定将无法像这样工作。

1> ContextMenu, Popups, DataGridColumns are not part of visual tree. So the binding using ElementName or RelativeSource wont work just like that.

2> 当您不想在特定情况下显示上下文菜单时，请使用触发器从视觉本身取消设置上下文菜单。

      <TextBlock Text="ContextMenu is not shown when DataContext.IsShow is false"}">
            <TextBlock.Style>
                <Style TargetType="{x:Type TextBlock}">
                    <Setter Property="ContextMenu"
                            Value="{StaticResource TextBlockContextMenu}" />
                   <Style.Triggers>
                       <DataTrigger Binding="{Binding IsShow}"
                                    Value="False">
                            <Setter Property="ContextMenu"
                                    Value="{x:Null}" />
                       </DataTrigger>
                   </Style.Triggers>
                </Style>
            </TextBlock.Style>
      </TextBlock>

3>要将这些项目附加到可视化树上，以便进行绑定，我们使用proxy元素方法...

3> To attach these items to the visual tree, so that binding works, we use the proxy element method...

我更喜欢第二步。

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