DataGridRow 背景颜色的 WPF 样式触发器被 AlternatingRowBackground 画笔取代

Question

我有一个 WPF DataGrid，它有一个 AlternatingRowBackground 画笔。它被配置为每隔一行着色。我想在鼠标悬停时执行一些操作来突出显示当前行。然而，Style Trigger 似乎输给了 AlternatingRowBackground 画笔。当鼠标悬停在...上时，我得到了所需的行着色...但仅限于未使用 AlternatingRowBackground 画笔绘制的行。

这是 Windows.Resources 中的样式：

<Window.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="/Skins/MainSkin.xaml" />
            </ResourceDictionary.MergedDictionaries>
            <Style TargetType="{x:Type DataGridRow}">
                <Style.Triggers>
                    <Trigger Property="IsMouseOver"
                             Value="True">
                        <Setter Property="Background"
                                Value="Red" />
                        <Setter Property="FontWeight"
                                Value="ExtraBold" />
                        <Setter Property="Height"
                                Value="20" />
                    </Trigger>
                </Style.Triggers>
            </Style>
        </ResourceDictionary>
    </Window.Resources>

这是 DataGrid：

    <DataGrid Margin="25,15,25,0"
              VerticalAlignment="Top"
              ItemsSource="{Binding DocumentTypeList}"
              AutoGenerateColumns="False"
              Height="500"
              AlternationCount="2"
              FrozenColumnCount="2"
              AlternatingRowBackground="{DynamicResource AlternatingRow}">
        <DataGrid.Columns>
            <DataGridTextColumn Binding="{Binding Abbreviation}"
                                Header="Abbreviation" />
            <DataGridTextColumn Binding="{Binding Title}"
                                Header="Title" />

            <DataGridTextColumn Binding="{Binding Fee}"
                                Header="Fee" />
            <DataGridTextColumn Binding="{Binding SpecialInstructions}"
                                Header="Special Instructions" />
        </DataGrid.Columns>
    </DataGrid>

有没有办法宣布绝对获胜者？问题是一个等级问题吗？在我看来，AlternatingRowBackground 画笔胜出，因为它与声明的最具体部分直接相关。

更新：这是基于@Val的指导的正确语法：

<Window.Resources>
    <ResourceDictionary>
        <ResourceDictionary.MergedDictionaries>
            <ResourceDictionary Source="/Skins/MainSkin.xaml" />
        </ResourceDictionary.MergedDictionaries>
        <Style TargetType="{x:Type DataGridRow}">
            <Style.Triggers>
                <Trigger Property="IsMouseOver"
                         Value="True">
                    <Setter Property="Background"
                            Value="Red" />
                    <Setter Property="FontWeight"
                            Value="ExtraBold" />
                    <Setter Property="Height"
                            Value="20" />
                </Trigger>
            </Style.Triggers>
        </Style>
        <Style TargetType="{x:Type DataGrid}">
            <Setter Property="AlternatingRowBackground" Value="{DynamicResource AlternatingRow}"/>
        </Style>
    </ResourceDictionary>
</Window.Resources>

以及DataGrid（减去AlternatingRowBackground画笔）：

<DataGrid Margin="25,15,25,0"
              VerticalAlignment="Top"
              ItemsSource="{Binding DocumentTypeList}"
              AutoGenerateColumns="False"
              Height="500"
              AlternationCount="2"
              FrozenColumnCount="2">
        <DataGrid.Columns>
            <DataGridTextColumn Binding="{Binding Abbreviation}"
                                Header="Abbreviation" />
            <DataGridTextColumn Binding="{Binding Title}"
                                Header="Title" />

            <DataGridTextColumn Binding="{Binding Fee}"
                                Header="Fee" />
            <DataGridTextColumn Binding="{Binding SpecialInstructions}"
                                Header="Special Instructions" />
        </DataGrid.Columns>
    </DataGrid>

Answer 1

有两种方法可以做到这一点，但都不是特别明显。由于 DataGridRow 将背景属性从父 DataGrid 传输（在代码中）到行中的本地值，正如您所指出的，它将优先于触发器设置的值。

第一种（也是最简单的）方法是不使用 AlternatingRowBackground 或 RowBackground，而是按照 Val 建议使用触发器来交替背景颜色。但他的示例并不完整，并且无法按原样运行。正确的样式和用法如下。请注意，您需要在 DataGrid 上设置 AlternationCount，否则行将永远不会获得交替索引。

<DataGrid AlternationCount="2">
    <DataGrid.RowStyle>
        <Style TargetType="DataGridRow">
            <Setter Property="Background" Value="White"/>
            <Setter Property="FontWeight" Value="Normal"/>
            <Style.Triggers>
                <Trigger Property="AlternationIndex" Value="1">
                    <Setter Property="Background" Value="Wheat"/>
                    <Setter Property="FontWeight" Value="Bold"/>
                </Trigger>
                <Trigger Property="IsMouseOver" Value="True">
                    <Setter Property="Background" Value="Khaki"/>
                </Trigger>
            </Style.Triggers>
        </Style>
    </DataGrid.RowStyle>
</DataGrid>

第二个选项是使用 VisualStateManager。这使您可以更好地控制不同的视觉状态，但它更冗长。幸运的是，使用 Blend 复制默认控件模板非常容易。除了处于 MouseOver 状态的 Storyboard 以及我在 selectedScrollingGrid 上设置背景之外，以下大部分内容均未更改。

抱歉，包装，但就像我说的，它有点冗长。

<DataGrid AlternationCount="2" AlternatingRowBackground="Wheat">
  <DataGrid.RowStyle>
    <Style TargetType="DataGridRow">
      <Setter Property="Template">
        <Setter.Value>
          <ControlTemplate TargetType="DataGridRow">
            <Border x:Name="DGR_Border" 
                    Background="{TemplateBinding Background}"
                    BorderBrush="{TemplateBinding BorderBrush}"
                    BorderThickness="{TemplateBinding BorderThickness}"
                    SnapsToDevicePixels="True">
              <VisualStateManager.VisualStateGroups>
                <VisualStateGroup x:Name="CommonStates">
                  <VisualState x:Name="Normal"/>
                  <VisualState x:Name="Normal_AlternatingRow"/>
                  <VisualState x:Name="Unfocused_Editing"/>
                  <VisualState x:Name="Normal_Editing"/>
                  <VisualState x:Name="Unfocused_Selected"/>
                  <VisualState x:Name="Normal_Selected"/>
                  <VisualState x:Name="MouseOver_Unfocused_Editing"/>
                  <VisualState x:Name="MouseOver_Editing"/>
                  <VisualState x:Name="MouseOver_Unfocused_Selected"/>
                  <VisualState x:Name="MouseOver_Selected"/>
                  <VisualState x:Name="MouseOver">
                    <Storyboard Storyboard.TargetName="Highlight">
                      <ColorAnimation Duration="0" Storyboard.TargetProperty="Color" To="Khaki"/>
                    </Storyboard>
                  </VisualState>
                </VisualStateGroup>
              </VisualStateManager.VisualStateGroups>
              <SelectiveScrollingGrid x:Name="selectiveScrollingGrid">
                <SelectiveScrollingGrid.Background>
                  <SolidColorBrush x:Name="Highlight" Color="Transparent"/>
                </SelectiveScrollingGrid.Background>
                <SelectiveScrollingGrid.ColumnDefinitions>
                  <ColumnDefinition Width="Auto"/>
                  <ColumnDefinition Width="*"/>
                </SelectiveScrollingGrid.ColumnDefinitions>
                <SelectiveScrollingGrid.RowDefinitions>
                  <RowDefinition Height="*"/>
                  <RowDefinition Height="Auto"/>
                </SelectiveScrollingGrid.RowDefinitions>
                <DataGridCellsPresenter Grid.Column="1" ItemsPanel="{TemplateBinding ItemsPanel}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
                <DataGridDetailsPresenter Grid.Column="1" Grid.Row="1" SelectiveScrollingGrid.SelectiveScrollingOrientation="{Binding AreRowDetailsFrozen, ConverterParameter={x:Static SelectiveScrollingOrientation.Vertical}, Converter={x:Static DataGrid.RowDetailsScrollingConverter}, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}}" Visibility="{TemplateBinding DetailsVisibility}"/>
                <DataGridRowHeader Grid.RowSpan="2" SelectiveScrollingGrid.SelectiveScrollingOrientation="Vertical" Visibility="{Binding HeadersVisibility, ConverterParameter={x:Static DataGridHeadersVisibility.Row}, Converter={x:Static DataGrid.HeadersVisibilityConverter}, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}}"/>
              </SelectiveScrollingGrid>
            </Border>
          </ControlTemplate>
        </Setter.Value>
      </Setter>
    </Style>
  </DataGrid.RowStyle>
</DataGrid>

Answer 2

过去对这种事情对我有用的是在触发器之外使用设置器，例如：

<Style TargetType="{x:Type DataGridRow}">
    <Style.Triggers>
        <Trigger Property="IsMouseOver"
                 Value="True">
             <Setter Property="Background"
                     Value="Red" />
             <Setter Property="FontWeight"
                     Value="ExtraBold" />
             <Setter Property="Height"
                     Value="20" />
        </Trigger>
    </Style.Triggers>
    <Setter Property="AlternatingRowBackground"
            Value="{DynamicResource AlternatingRow}"/>
</Style>

并且它们删除 DataGrid 本身上的属性绑定。尽管我通常使用数据触发器来执行此操作，而不是使用动态资源绑定。但仍然值得一试