How to change the foreground of selected ComboBoxItem with icon?

问题

I'm trying to change the foreground color of ComboBoxItem, however it doesn't work as expected.

The default color for the foreground is black, and I want to set selected item foreground to white when opening the dropdown/popup. It works fine when the ComboBoxItem contains only text content. However when ComboBoxItem including non-plain text content is selected, the foreground remains white after closing the dropdown/popup.

Xaml:

    <ComboBox HorizontalAlignment="Left" VerticalAlignment="Top" Width="120" Style="{DynamicResource ComboBoxStyle1}" ItemContainerStyle="{DynamicResource ComboBoxItemStyle1}">
        <ComboBoxItem>
            <StackPanel Orientation="Horizontal">
                <Rectangle Height="16" Width="16" Fill="Red"/>
                <TextBlock Text="123"/>
            </StackPanel>
        </ComboBoxItem>
        <ComboBoxItem Content="456"/>
        <ComboBoxItem>
            <StackPanel Orientation="Horizontal">
                <Rectangle Height="16" Width="16" Fill="Red"/>
                <TextBlock Text="789"/>
            </StackPanel>
        </ComboBoxItem>
    </ComboBox>

That displays as the following image:

Please find the below image for more information.

<Style x:Key="ComboBoxStyle1" TargetType="{x:Type ComboBox}">
    <Setter Property="Foreground" Value="Black"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type ComboBox}">
                <Grid x:Name="MainGrid" SnapsToDevicePixels="true">
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="*"/>
                        <ColumnDefinition MinWidth="{DynamicResource {x:Static SystemParameters.VerticalScrollBarWidthKey}}" Width="0"/>
                    </Grid.ColumnDefinitions>
                    <Popup x:Name="PART_Popup" AllowsTransparency="true" Grid.ColumnSpan="2" IsOpen="{Binding IsDropDownOpen, RelativeSource={RelativeSource TemplatedParent}}" Margin="1" PopupAnimation="{DynamicResource {x:Static SystemParameters.ComboBoxPopupAnimationKey}}" Placement="Bottom">
                        <Themes:SystemDropShadowChrome x:Name="Shdw" Color="Transparent" MaxHeight="{TemplateBinding MaxDropDownHeight}" MinWidth="{Binding ActualWidth, ElementName=MainGrid}">
                            <Border x:Name="DropDownBorder" BorderBrush="{DynamicResource {x:Static SystemColors.WindowFrameBrushKey}}" BorderThickness="1" Background="{DynamicResource {x:Static SystemColors.WindowBrushKey}}">
                                <ScrollViewer x:Name="DropDownScrollViewer">
                                    <Grid RenderOptions.ClearTypeHint="Enabled">
                                        <Canvas HorizontalAlignment="Left" Height="0" VerticalAlignment="Top" Width="0">
                                            <Rectangle x:Name="OpaqueRect" Fill="{Binding Background, ElementName=DropDownBorder}" Height="{Binding ActualHeight, ElementName=DropDownBorder}" Width="{Binding ActualWidth, ElementName=DropDownBorder}"/>
                                        </Canvas>
                                        <ItemsPresenter x:Name="ItemsPresenter" KeyboardNavigation.DirectionalNavigation="Contained" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
                                    </Grid>
                                </ScrollViewer>
                            </Border>
                        </Themes:SystemDropShadowChrome>
                    </Popup>
                    <ToggleButton x:Name="ToggleButton" BorderBrush="{TemplateBinding BorderBrush}" Background="{TemplateBinding Background}" Grid.ColumnSpan="2" IsChecked="{Binding IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource ComboBoxReadonlyToggleButton}"/>
                    <ContentPresenter ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}" ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}" Content="{TemplateBinding SelectionBoxItem}" ContentStringFormat="{TemplateBinding SelectionBoxItemStringFormat}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" IsHitTestVisible="false" Margin="{TemplateBinding Padding}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
                </Grid>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsChecked" Value="true" SourceName="ToggleButton">
                        <Setter Property="Foreground" Value="White"/>
                    </Trigger>
                    <Trigger Property="HasDropShadow" SourceName="PART_Popup" Value="true">
                        <Setter Property="Margin" TargetName="Shdw" Value="0,0,5,5"/>
                        <Setter Property="Color" TargetName="Shdw" Value="#71000000"/>
                    </Trigger>
                    <Trigger Property="HasItems" Value="false">
                        <Setter Property="Height" TargetName="DropDownBorder" Value="95"/>
                    </Trigger>
                    <Trigger Property="IsEnabled" Value="false">
                        <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
                        <Setter Property="Background" Value="#FFF4F4F4"/>
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

<Style x:Key="ComboBoxItemStyle1" TargetType="{x:Type ComboBoxItem}">
    <Setter Property="Padding" Value="3,0,3,0"/>
    <Setter Property="Background" Value="Transparent"/>
    <Setter Property="Foreground" Value="Black"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type ComboBoxItem}">
                <Border x:Name="Bd" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Padding="{TemplateBinding Padding}" SnapsToDevicePixels="true">
                    <ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
                </Border>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsMouseOver" Value="true">
                        <Setter Property="Background" TargetName="Bd" Value="LightBlue"/>
                    </Trigger>
                    <Trigger Property="IsSelected" Value="true">
                        <Setter Property="Background" TargetName="Bd" Value="Blue"/>
                        <Setter Property="Foreground" Value="White"/>
                    </Trigger>
                    <Trigger Property="IsEnabled" Value="false">
                        <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

回答1:

Finally I figured out a solution by thinking backwards.

First I set the foreground of ComboBox to white when opening the dropdown/popup and make ComboBoxItem inherit the foreground color.

ComboBoxStyle:

<Trigger Property="IsDropDownOpen" Value="true">
  <Setter Property="Foreground" Value="White"/>
</Trigger>

ComboBoxItemStyle:

<Setter Property="Foreground" Value="{Binding Foreground,RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type ComboBox}}}"/>

Then, I change the foreground color of unselected ComboBoxItem to black.

<Trigger Property="IsSelected" Value="false">
  <Setter Property="Foreground" Value="Black"/>
</Trigger>

Here is the entire xaml:

<Style x:Key="ComboBoxStyle1" TargetType="{x:Type ComboBox}">
    <Setter Property="Foreground" Value="Black"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type ComboBox}">
                <Grid x:Name="MainGrid" SnapsToDevicePixels="true">
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="*"/>
                        <ColumnDefinition MinWidth="{DynamicResource {x:Static SystemParameters.VerticalScrollBarWidthKey}}" Width="0"/>
                    </Grid.ColumnDefinitions>
                    <Popup x:Name="PART_Popup" AllowsTransparency="true" Grid.ColumnSpan="2" IsOpen="{Binding IsDropDownOpen, RelativeSource={RelativeSource TemplatedParent}}" Margin="1" PopupAnimation="{DynamicResource {x:Static SystemParameters.ComboBoxPopupAnimationKey}}" Placement="Bottom">
                        <Themes:SystemDropShadowChrome x:Name="Shdw" Color="Transparent" MaxHeight="{TemplateBinding MaxDropDownHeight}" MinWidth="{Binding ActualWidth, ElementName=MainGrid}">
                            <Border x:Name="DropDownBorder" BorderBrush="{DynamicResource {x:Static SystemColors.WindowFrameBrushKey}}" BorderThickness="1" Background="{DynamicResource {x:Static SystemColors.WindowBrushKey}}">
                                <ScrollViewer x:Name="DropDownScrollViewer">
                                    <Grid RenderOptions.ClearTypeHint="Enabled">
                                        <Canvas HorizontalAlignment="Left" Height="0" VerticalAlignment="Top" Width="0">
                                            <Rectangle x:Name="OpaqueRect" Fill="{Binding Background, ElementName=DropDownBorder}" Height="{Binding ActualHeight, ElementName=DropDownBorder}" Width="{Binding ActualWidth, ElementName=DropDownBorder}"/>
                                        </Canvas>
                                        <ItemsPresenter x:Name="ItemsPresenter" KeyboardNavigation.DirectionalNavigation="Contained" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
                                    </Grid>
                                </ScrollViewer>
                            </Border>
                        </Themes:SystemDropShadowChrome>
                    </Popup>
                    <ToggleButton x:Name="ToggleButton" BorderBrush="{TemplateBinding BorderBrush}" Background="{TemplateBinding Background}" Grid.ColumnSpan="2" IsChecked="{Binding IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource ComboBoxReadonlyToggleButton}"/>
                    <ContentPresenter ContentTemplate="{TemplateBinding SelectionBoxItemTemplate}" ContentTemplateSelector="{TemplateBinding ItemTemplateSelector}" Content="{TemplateBinding SelectionBoxItem}" ContentStringFormat="{TemplateBinding SelectionBoxItemStringFormat}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" IsHitTestVisible="false" Margin="{TemplateBinding Padding}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
                </Grid>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsDropDownOpen" Value="true">
                        <Setter Property="Foreground" Value="White"/>
                    </Trigger>
                    <Trigger Property="HasDropShadow" SourceName="PART_Popup" Value="true">
                        <Setter Property="Margin" TargetName="Shdw" Value="0,0,5,5"/>
                        <Setter Property="Color" TargetName="Shdw" Value="#71000000"/>
                    </Trigger>
                    <Trigger Property="HasItems" Value="false">
                        <Setter Property="Height" TargetName="DropDownBorder" Value="95"/>
                    </Trigger>
                    <Trigger Property="IsEnabled" Value="false">
                        <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
                        <Setter Property="Background" Value="#FFF4F4F4"/>
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>
<Style x:Key="ComboBoxItemStyle1" TargetType="{x:Type ComboBoxItem}">
    <Setter Property="Padding" Value="3,0,3,0"/>
    <Setter Property="Background" Value="Transparent"/>
    <Setter Property="Foreground" Value="{Binding Foreground,RelativeSource={RelativeSource FindAncestor,AncestorType={x:Type ComboBox}}}"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type ComboBoxItem}">
                <Border x:Name="Bd" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Padding="{TemplateBinding Padding}" SnapsToDevicePixels="true">
                    <ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
                </Border>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsMouseOver" Value="true">
                        <Setter Property="Background" TargetName="Bd" Value="LightBlue"/>
                    </Trigger>
                    <Trigger Property="IsSelected" Value="true">
                        <Setter Property="Background" TargetName="Bd" Value="Blue"/>
                    </Trigger>
                    <Trigger Property="IsSelected" Value="false">
                        <Setter Property="Foreground" Value="Black"/>
                    </Trigger>
                    <Trigger Property="IsEnabled" Value="false">
                        <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

来源：https://stackoverflow.com/questions/35724768/how-to-change-the-foreground-of-selected-comboboxitem-with-icon

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xaml

combobox