wpf - 在 WPF 样式中触发多个条件的正确方法是什么

Question

我的 WPF 应用程序有一个 DataGrid控制其中。我有 DataGridRow 的默认自定义样式效果很好的类。然而，对于这一特殊的 DataGrid在这个特定的屏幕上，我需要不同的自定义样式。

每行中的项目都有一个 bool属性，设置后，我想用不同的前景色和背景色显示该行。 However, when the row is selected AND when that property is set, I want a different foreground and background color to show that it's selected AND the property is set to true.

这是我尝试过的:

<Style TargetType="DataGridRow" x:Key="CameraStyle">
    <Setter Property="Foreground" Value="{DynamicResource TextForeground}" />
    <Setter Property="Background" Value="{DynamicResource DataBackground}" />
    <Style.Triggers>
        <MultiDataTrigger>
            <MultiDataTrigger.Conditions>
                <Condition Property="IsSelected" Value="False" />
                <Condition Binding="{Binding Path=IsInLiveMode}" Value="True" />
            </MultiDataTrigger.Conditions>
            <Setter Property="Foreground" Value="Red" />
            <Setter Property="Background" Value="Yellow" />
        </MultiDataTrigger>
        <MultiDataTrigger>
            <MultiDataTrigger.Conditions>
                <Condition Property="IsSelected" Value="True" />
                <Condition Binding="{Binding Path=IsInLiveMode}" Value="True" />
            </MultiDataTrigger.Conditions>
            <Setter Property="Background"  Value="DarkOrange" />
            <Setter Property="BorderBrush" Value="{DynamicResource DataBorder}" />
            <Setter Property="Foreground"  Value="DarkRed" />
        </MultiDataTrigger>
    </Style.Triggers>
</Style>

这给了我一个“绑定(bind)必须是非空”错误，我认为这是因为没有 Binding MultiDataTrigger 中第一个条件的属性。

在 XAML 中编写此代码的正确方法是什么？

编辑:

在尝试了 nemesv 和 Rachel 的答案后，代码现在可以编译并运行。但是，我为 IsSelected = true 和 IsInLiveMode = true 案例选择的颜色没有显示出来。这是我现在拥有的:

    <Style TargetType="DataGridRow" x:Key="CameraStyle">
        <Setter Property="Background" Value="{DynamicResource DataBackground}" />
        <Setter Property="Foreground" Value="{DynamicResource TextForeground}" />
        <Style.Triggers>
            <MultiDataTrigger>
                <MultiDataTrigger.Conditions>
                    <Condition Binding="{Binding Path=IsSelected, RelativeSource={RelativeSource Self}}" Value="False" />
                    <Condition Binding="{Binding Path=IsInLiveMode}" Value="True" />
                </MultiDataTrigger.Conditions>
                <Setter Property="Background" Value="Yellow" />
                <Setter Property="Foreground" Value="Red" />
            </MultiDataTrigger>
            <MultiDataTrigger>
                <MultiDataTrigger.Conditions>
                    <Condition Binding="{Binding Path=IsSelected, RelativeSource={RelativeSource Self}}" Value="True" />
                    <Condition Binding="{Binding Path=IsInLiveMode}" Value="False" />
                </MultiDataTrigger.Conditions>
                <Setter Property="Background"  Value="{DynamicResource DataBackgroundSelected}" />
                <Setter Property="BorderBrush" Value="{DynamicResource DataBorder}" />
                <Setter Property="Foreground"  Value="{DynamicResource DataForegroundSelected}" />
            </MultiDataTrigger>
            <MultiDataTrigger>
                <MultiDataTrigger.Conditions>
                    <Condition Binding="{Binding Path=IsSelected, RelativeSource={RelativeSource Self}}" Value="True" />
                    <Condition Binding="{Binding Path=IsInLiveMode}" Value="True" />
                </MultiDataTrigger.Conditions>
                <Setter Property="Background"  Value="DarkOrange" />
                <Setter Property="BorderBrush" Value="{DynamicResource DataBorder}" />
                <Setter Property="Foreground"  Value="DarkRed" />
            </MultiDataTrigger>
        </Style.Triggers>
    </Style>

关于为什么有问题的案例不起作用的任何想法？

Answer 1

您关于缺少绑定(bind)的假设是正确的。

来自 MSDN MultiDataTrigger.Conditions :

For a MultiDataTrigger, each condition in the collection must set both the Binding and Value properties.

您可以使用 RelativeSource Self 解决此问题在绑定(bind)中引用自己:

<MultiDataTrigger.Conditions>
    <Condition Binding="{Binding RelativeSource={RelativeSource Self},
         Path=IsSelected}" Value="True" />
    <Condition Binding="{Binding Path=IsInLiveMode}" Value="True" />
</MultiDataTrigger.Conditions>