Using VisualStates in DataGridRow ControlTemplate-CodePudding

I created a custom style for a DataGridRow which also changes the control template which I obtained in Visual Studio (right click on the control and chose to edit copy of the template (sorry, I don't have the exact translation)). First I omitted the entire VisualStateManager-stuff and everything worked fine. But when I want to have alternating row colors I guess I have to use the VisualStateManager with the state 'Normal_AlternatingRow'. Unfortunately, I am getting this error as soon as the VisualStateManager is uncommented:

'[Unknown]' property does not point to a dependencyobject in path '(0).(1)[0].(2)'

This is my DataGridRow style with template:

<Style x:Key="DataGridRowStyle" TargetType="{x:Type DataGridRow}">
<Setter Property="HeaderStyle" Value="{StaticResource DataGridRowHeaderStyle}"/>
<Setter Property="Background" Value="{StaticResource ControlLightBackgroundBrush}"/>
<Setter Property="SnapsToDevicePixels" Value="true"/>
<Setter Property="Template">
  <Setter.Value>
    <ControlTemplate TargetType="{x:Type DataGridRow}">
      <Border x:Name="DGR_Border" BorderBrush="{TemplateBinding BorderBrush}" 
              BorderThickness="{TemplateBinding BorderThickness}" 
              Background="{TemplateBinding Background}" SnapsToDevicePixels="True"                  >
        <SelectiveScrollingGrid>
          <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>
        <VisualStateManager.VisualStateGroups>
          <VisualStateGroup x:Name="CommonStates">
            <VisualState x:Name="Normal"/>
            <VisualState x:Name="Normal_AlternatingRow">
              <Storyboard>
                <ColorAnimationUsingKeyFrames Storyboard.TargetName="DGR_Border"
                                              Storyboard.TargetProperty="(Panel.Background).(GradientBrush.GradientStops)[0].(GradientStop.Color)">
                  <EasingColorKeyFrame KeyTime="0" Value="Yellow"/>
                </ColorAnimationUsingKeyFrames>                   
              </Storyboard>
            </VisualState>
          </VisualStateGroup>
        </VisualStateManager.VisualStateGroups>
      </Border>
    </ControlTemplate>
  </Setter.Value>
</Setter>
<Style.Triggers>
  <Trigger Property="IsNewItem" Value="True">
    <Setter Property="Margin" Value="{Binding NewItemMargin, RelativeSource={RelativeSource AncestorType={x:Type DataGrid}}}"/>
  </Trigger>
  <Trigger Property="IsSelected" Value="True">
    <Setter Property="Background" Value="{StaticResource HighlightBrush}"/>
  </Trigger>
</Style.Triggers>

I haven't used visual states in control templates before.

Thanks for any help!

CodePudding user response：

The current implementation assumes that the Background property is set to a GradientBrush.

If ControlLightBackgroundBrush is a SolidColorBrush, the following should work:

<VisualState x:Name="Normal_AlternatingRow">
    <Storyboard>
        <ColorAnimationUsingKeyFrames Storyboard.TargetName="DGR_Border"
                                      Storyboard.TargetProperty="(Button.Background).(SolidColorBrush.Color)">
            <EasingColorKeyFrame KeyTime="0" Value="Yellow"/>
        </ColorAnimationUsingKeyFrames>
    </Storyboard>
</VisualState>