wpf - 当面板中的元素具有焦点时更改 WPF StackPanel 背景颜色

Question

如果我在 StackPanel 中有一组控件，当 StackPanel 中的任何控件获得焦点时，是否有一种通用的方法来更改 stackpanel 的背景？（并且当 StackPanel 中没有控件具有焦点时，显然将背景切换回来）。下面的代码对我有用，但最好有一种通用的方法来完成此任务，而不是在我的页面中列出每个 StackPanel 中的每个控件。

谢谢！

<StackPanel Margin="5">
    <StackPanel.Style>
    <Style TargetType="{x:Type StackPanel}">
        <Style.Triggers>
            <DataTrigger Binding="{Binding IsFocused, ElementName=chkOccupiedByMortgagor}" Value="true">
                <Setter Property="Background" Value="Gray" />
                <Setter Property="Opacity" Value=".5" />
            </DataTrigger>
            <DataTrigger Binding="{Binding IsFocused, ElementName=chkOccupiedByNewOwner}" Value="true">
                <Setter Property="Background" Value="Gray" />
                <Setter Property="Opacity" Value=".5" />
            </DataTrigger>
        </Style.Triggers>
    </Style>
</StackPanel.Style>
<CheckBox Margin="2" x:Name="chkOccupiedByMortgagor">Mortgagor</CheckBox>
<CheckBox Margin="2" x:Name="chkOccupiedByNewOwner">New Owner</CheckBox>
<CheckBox Margin="2" x:Name="chkOccupiedByTenant">Tenant</CheckBox>
<CheckBox Margin="2" x:Name="chkOccupiedByUnknownOccupant">Unknown Occupant</CheckBox>
</StackPanel> 

Answer 1

是的。你可以这样做。只需使用IsKeyboardFocusWithin属性作为触发器，如下所示：

<StackPanel Margin="5">
    <StackPanel.Style>
        <Style TargetType="{x:Type StackPanel}">
            <Style.Triggers>
                    <DataTrigger Binding="{Binding RelativeSource={RelativeSource Self}, Path=IsKeyboardFocusWithin}" Value="True">
                    <Setter Property="Background" Value="Gray" />
                    <Setter Property="Opacity" Value=".5" />
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </StackPanel.Style>
    <CheckBox Margin="2">Mortgagor</CheckBox>
    <CheckBox Margin="2">New Owner</CheckBox>
    <CheckBox Margin="2">Tenant</CheckBox>
    <CheckBox Margin="2">Unknown Occupant</CheckBox>
</StackPanel>

Do remember though, that you need to tell the trigger to look for the property in the same element, hence, RelativeSource={RelativeSource Self}. Alternatively, you can name the stack panel and use this xaml too:

<StackPanel Margin="5" x:Name="stackPanel">
    ...
                <DataTrigger Binding="{Binding ElementName=stackPanel, Path=IsKeyboardFocusWithin}" Value="True">
    ...