Question

这是我的ContextMenu的风格：

<Style x:Key="DIOStyle" TargetType="ContentControl">
        <Setter Property="Tag" Value="{Binding Content,RelativeSource={RelativeSource Mode=Self}}"/>
        <Setter Property="ContextMenu">
            <Setter.Value>
                <ContextMenu>
                    <MenuItem Style="{StaticResource DeleteMenuItemStyle}"/>
                    <!--<MenuItem Header="Normality">
                        <MenuItem Style="{StaticResource NcMenuItemStyle}"/>
                        <MenuItem Style="{StaticResource NaMenuItemStyle}"/>
                    </MenuItem>-->
                    <MenuItem Style="{StaticResource BothContactsMenuItemStyle}"/>
                </ContextMenu>
            </Setter.Value>
        </Setter>
...

这是我的MenuItem的样式：

<Style x:Key="BothContactsMenuItemStyle" TargetType="MenuItem">
        <Setter Property="Header" Value="Both Contacts"/>
        <Setter Property="Command" Value="{Binding PlacementTarget.Tag.BothNaNcChangeCommand,RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=ContextMenu}}"/>
        <Setter Property="Icon">
            <Setter.Value>
                <Image Style="{StaticResource Tick16Style}" Visibility="{Binding PlacementTarget.Tag.BothNaNc, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=ContextMenu}, Converter={StaticResource BoolToVis}}"/>
            </Setter.Value>
        </Setter>
    </Style>

命令绑定正在运行，而图标可见性绑定给我这个错误：

System.Windows.Data错误：4：找不到绑定源参考'RelativeSource FindAncestor， AncestorType ='System.Windows.Controls.ContextMenu'，AncestorLevel ='1''。 BindingExpression：路径= PlacementTarget.Tag.BothNaNc;的DataItem = NULL; target元素是'Image'（Name =''）;目标属性是'可见性' （输入“可见性”）

为什么呢？请注意，这是有效的：

<MenuItem Header="TEST" Visibility="{Binding PlacementTarget.Tag.BothNaNc, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=ContextMenu}, Converter={StaticResource BoolToVis}}"/>

Answer 1

您可以将Image元素定义为资源。这应该有效：

<Image x:Key="img" x:Shared="False"
               Style="{StaticResource Tick16Style}"
               Visibility="{Binding PlacementTarget.Tag.BothNaNc, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=ContextMenu},
                            Converter={StaticResource BoolToVis}}"/>

<Style x:Key="BothContactsMenuItemStyle" TargetType="MenuItem">
    <Setter Property="Header" Value="Both Contacts"/>
    <Setter Property="Command" Value="{Binding PlacementTarget.Tag.BothNaNcChangeCommand, RelativeSource={RelativeSource Mode=FindAncestor,AncestorType=ContextMenu}}"/>
    <Setter Property="Icon" Value="{StaticResource img}" />
</Style>

如果您将Icon属性设置为您在Image中内联定义的<Setter.Value>元素，就像您当前正在执行的那样，它将从父{继承DataContext {1}}或Window或定义UserControl的任何地方。

WPF ContextMenu：MenuItem图标可见性绑定错误

1 个答案: