使用DataTrigger绑定到样式中的Self

Question

我有一个按钮样式.根据Button是否启用,我想更改背景.这就是它的样子:

<Style x:Key="MyButtonStyle" TargetType="Button">
    <Style.Triggers>
        <DataTrigger Binding="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=Button}, Path=IsEnabled, PresentationTraceSources.TraceLevel=High}" Value="False">
            <Setter Property="Background" Value="Purple"/>
        </DataTrigger>
        <DataTrigger Binding="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=Button}, Path=IsEnabled, PresentationTraceSources.TraceLevel=High}" Value="True">
            <Setter Property="Background" Value="Yellow"/>
        </DataTrigger>
    </Style.Triggers>
</Style>

这只是一个基本的例子.实际上我需要一个MultiDataTrigger,但它甚至不能使用常规的DataTrigger.我只看到一个灰色按钮.

这是跟踪:

System.Windows.Data警告:56:为绑定创建BindingExpression(hash = 31767240)(hash = 6303779)
System.Windows.Data警告:58:路径:'IsEnabled'System.Windows.Data
警告:60:BindingExpression(hash = 31767240):默认模式已解析为OneWay
System.Windows.Data警告:61:BindingExpression(hash = 31767240):解析为PropertyChanged的默认更新触发器
System.Windows.Data警告:62:BindingExpression(hash = 31767240):附加到系统. Windows.Controls.Button.NoTarget(hash = 24311680)
System.Windows.Data警告:66:BindingExpression(hash = 31767240):RelativeSource(FindAncestor)需要树上下文
System.Windows.Data警告:65:BindingExpression(hash = 31767240) :Resolve source deferred
System.Windows.Data警告:67:BindingExpression(hash = 31767240):解析源
System.Windows.Data警告:70:BindingExpression(hash = 31767240):找到数据上下文元素:(OK)
System.Windows.数据警告:73:查找类型Button的祖先:查询网格(哈希= 35 377238)
System.Windows.Data警告:73:查找类型Button的祖先:查询ContentPresenter(hash = 51189900)
System.Windows.Data警告:73:查找类型Button的祖先:查询边框(hash = 48541090)
System.Windows.数据警告:73:查找类型Button的祖先:查询StartStopControl(hash = 22721178)
System.Windows.Data警告:73:查找类型Button的祖先:查询网格(哈希= 32321338)
System.Windows.Data警告:73:查找Button类型的祖先:查询ContentPresenter(hash = 31184590)
System.Windows.Data警告:73:查找类型的祖先Button:查询边框(hash = 37117888)
System.Windows.Data警告:73:查找类型Button的祖先:查询MenuPanelControl(hash = 873549)
System.Windows.Data警告:73:查找类型的祖先Button:查询网格(hash = 29953511)
System.Windows.Data警告:73:查找类型Button的祖先:查询ContentPresenter(hash = 42576376)
System.Windows.Data警告:73:查找类型Button的祖先:查询A dornerDecorator(hash = 66649760)
System.Windows.Data警告:73:查找类型Button的祖先:查询边框(hash = 23566381)
System.Windows.Data警告:73:查找类型Button的祖先:查询MainWindow(hash = 38392424)

看起来它贯穿整个可视化树,从放置Button的Grid开始.为什么它不以Button开头？

Answer 1

你为什么不把它改成Trigger？

  <Style x:Key="MyButtonStyle"
           TargetType="Button">
        <Style.Triggers>
            <Trigger Property="IsEnabled"
                     Value="False">
                <Setter Property="Background"
                        Value="Purple" />
            </Trigger>
            <Trigger Property="IsEnabled"
                     Value="True">
                <Setter Property="Background"
                        Value="Yellow" />
            </Trigger>
        </Style.Triggers>
    </Style>

或者如果你想要使用它,你不需要找到一个祖先,因为你当前在按钮上:

  <Style x:Key="MyButtonStyle"
           TargetType="Button">
        <Style.Triggers>
            <DataTrigger Binding="{Binding RelativeSource={RelativeSource Self}, Path=IsEnabled, PresentationTraceSources.TraceLevel=High}"
                         Value="False">
                <Setter Property="Background"
                        Value="Purple" />
            </DataTrigger>
            <DataTrigger Binding="{Binding RelativeSource={RelativeSource Self}, Path=IsEnabled, PresentationTraceSources.TraceLevel=High}"
                         Value="True">
                <Setter Property="Background"
                        Value="Yellow" />
            </DataTrigger>
        </Style.Triggers>
    </Style>

如果它对您没有帮助,您应该提供更多详细信息:原始XAML代码以及您的View Model代码.