WPF:如何使用DataTrigger设置TextBlock的Foreground属性

Question

这是我的XAML:

<TextBlock Name="SeverityText"
           Grid.Column="1"
           Grid.Row="0"
           Foreground="Red">
    <TextBlock.Triggers>

        <DataTrigger Binding="{Binding Path=Severity}">
            <DataTrigger.Value>
                <sm:Severity>Warning</sm:Severity>
            </DataTrigger.Value>
            <Setter TargetName="SeverityText"
                    Property="Foreground"
                    Value="Yellow" />
        </DataTrigger>
                 <DataTrigger Binding="{Binding Path=Severity}">
            <DataTrigger.Value>
                <sm:Severity>Information</sm:Severity>
            </DataTrigger.Value>
            <Setter TargetName="SeverityText"
                    Property="Foreground"
                    Value="White" />
        </DataTrigger>


    </TextBlock.Triggers>
    <TextBlock>Severity:</TextBlock>
    <TextBlock Text="{Binding Path=Severity}" />
</TextBlock>

这是我的错误消息:

在"ContentPresenter"类型上找不到静态成员"ForegroundProperty".

sm:严重性是我导入的枚举.

Answer 1

您的触发器和设置器需要以样式定义,而不是直接在TextBlock上定义:

<TextBlock>
    <TextBlock.Style>
        <Style TargetType="TextBlock">
            <Style.Triggers>

               <DataTrigger Binding="{Binding Severity}"> 
                   <DataTrigger.Value> 
                       <sm:Severity>Warning</sm:Severity> 
                   </DataTrigger.Value> 
                   <Setter TargetName="SeverityText" 
                           Property="Foreground" 
                           Value="Yellow" /> 
               </DataTrigger>

            </Style.Triggers>
        </Style>
    </TextBlock.Style>
</TextBlock>