WPF DataTrigger 找不到触发器目标

Question

<ListBox.ItemTemplate>
    <DataTemplate>
        <Grid x:Name="grid">
            <Grid.Background>
                <SolidColorBrush x:Name="backgroundBrush" Color="Transparent" Opacity="0.1"/>
            </Grid.Background>
        </Grid>
        <DataTemplate.Triggers>
            <DataTrigger Binding="{Binding IsExpanded}" Value="True">
                <Setter TargetName="backgroundBrush" Property="Color" Value="Green" />
            </DataTrigger>
            <Trigger SourceName="grid" Property="IsMouseOver" Value="True">
                <Trigger.EnterActions>
                    <BeginStoryboard>
                        <Storyboard>
                            <ColorAnimation Storyboard.TargetName="backgroundBrush"
                                 Storyboard.TargetProperty="Color"
                                 To="White" Duration="0:0:1.5"/>
                         </Storyboard>
                    </BeginStoryboard>
                </Trigger.EnterActions>
                <Trigger.ExitActions>
                    <BeginStoryboard>
                        <Storyboard>
                            <ColorAnimation Storyboard.TargetName="backgroundBrush"
                                Storyboard.TargetProperty="Color"
                                AccelerationRatio="1" Duration="0:0:1.5" />
                        </Storyboard>
                    </BeginStoryboard>
                </Trigger.ExitActions> 
            </Trigger>
        </DataTemplate.Triggers>
    </DataTemplate>
</ListBox.ItemTemplate>

不编译并出现错误“找不到触发目标 'backgroundBrush'。”

如果我删除 DataTrigger，它将编译并工作。如果我将 DataTrigger 更改为使用 TargetName="grid" Property="Background"它将编译和工作(但没有所需的不透明度)。

我哪里错了？

Answer 1

虽然我不确定为什么画笔不在名称范围内，但您可以通过换出画笔并在动画中“打点”到背景画笔的 Color 属性来做到这一点，如下所示:

<ListBox.ItemTemplate>
    <DataTemplate>
        <Grid x:Name="grid">
            <Grid.Background>
                <SolidColorBrush Color="Transparent" Opacity="0.1"/>
            </Grid.Background>
        </Grid>
        <DataTemplate.Triggers>
            <DataTrigger Binding="{Binding IsExpanded}" Value="True">
                <Setter TargetName="grid" Property="Background">
                    <Setter.Value>
                        <SolidColorBrush Color="Green" Opacity="0.1"/>
                    </Setter.Value>
                </Setter>
            </DataTrigger>
            <Trigger SourceName="grid" Property="IsMouseOver" Value="True">
                <Trigger.EnterActions>
                    <BeginStoryboard>
                        <Storyboard>
                            <ColorAnimation Storyboard.TargetName="grid"
                             Storyboard.TargetProperty="Background.Color"
                             To="White" Duration="0:0:1.5"/>
                        </Storyboard>
                    </BeginStoryboard>
                </Trigger.EnterActions>
                <Trigger.ExitActions>
                    <BeginStoryboard>
                        <Storyboard>
                            <ColorAnimation Storyboard.TargetName="grid"
                            Storyboard.TargetProperty="Background.Color"
                            AccelerationRatio="1" Duration="0:0:1.5" />
                        </Storyboard>
                    </BeginStoryboard>
                </Trigger.ExitActions>
            </Trigger>
        </DataTemplate.Triggers>
    </DataTemplate>
</ListBox.ItemTemplate>