用于DataGridRow的WPF样式触发器由AlternatingRowBackground Brush强制执行的背景颜色

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。我想在鼠标上做一些突出当前行的事情。但是，样式触发器似乎输给了AlternatingRowBackground画笔。我在鼠标上获得了所需的行颜色...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赢家？这个问题是一个层次结构吗？在我看来，AlternatingRowBackground画笔胜出，因为它直接与声明的最具体部分相关联。

更新：根据@ Val的指导，这是正确的语法：

<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>

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，两者都不是特别明显。由于DataGridRow将（从代码中）将背景属性从父DataGrid传输到行中的本地值，因此您将注意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，而是使用触发器来交替Val建议的背景颜色。他的例子并不完整，但不会按原样运作。正确的风格和用法如下。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，但它更加冗长。幸运的是，使用Blend复制默认控件模板非常容易。除了MouseOver状态中的Storyboard之外，以下大部分内容都没有改变，我在selectiveScrollingGrid上设置了背景。

对不起包装，但就像我说的那样，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

过去使用这种方法对我有用的是在触发器之外使用setter，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>

他们删除了DataGrid本身的属性绑定。虽然我通常使用数据触发器执行此操作，但通常不使用动态资源绑定。但仍然值得一试