当IsEnabled = False且IsEditable = False时，WPF组合框选择的项目文本不会变灰

Question

使用以下代码，组合框的所选项目的文本正常显示（即黑色）。我希望在禁用控件时它显示为灰色。但是，如果我设置IsEditable=True，那么它会变灰，但我不希望它可以编辑。

<Window x:Class="WpfApp1.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525">
    <Grid>
        <ComboBox Width="150" Height="23" IsEnabled="False" SelectedIndex="0" IsEditable="False">
            <TextBlock>Hello</TextBlock>
            <TextBlock>World</TextBlock>
        </ComboBox>
    </Grid>
</Window>

Answer 1

要在禁用时将组合框项目的颜色固定为灰色，请执行以下操作，这将修复UI中的所有组合框。

将此代码粘贴到<Window.Resources>代码的Xaml标记内：

<Style TargetType="{x:Type ComboBox}">
    <Style.Triggers>
        <Trigger Property="IsEnabled"
                 Value="False">
            <Setter Property="Foreground"
                    Value="Gray"/>
        </Trigger>
    </Style.Triggers>
</Style>

Answer 2

我已经解压缩了ComboBox模板（在Designer中左键单击ComboBox - ＆gt;编辑模板 - ＆gt;编辑副本）并在ComboBoxToggleButton模板中更改了IsEnabled = false and IsEditable = false的MultiDataTrigger，以将相同的Background和BorderBrush设置为IsEnable = false and IsEditable = true，还为ComboBox Style中的相同属性添加了一个MultiTrigger，用于设置Foreground颜色。结果非常类似于您想要实现的目标。

这是完整的XAML

<Window
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApp1"
        xmlns:sys="clr-namespace:System;assembly=mscorlib"
        xmlns:Themes="clr-namespace:Microsoft.Windows.Themes;assembly=PresentationFramework.Aero2" x:Class="WpfApp1.MainWindow"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Window.Resources>
        <ResourceDictionary>
            <Style x:Key="FocusVisual">
                <Setter Property="Control.Template">
                    <Setter.Value>
                        <ControlTemplate>
                            <Rectangle Margin="2" SnapsToDevicePixels="true" Stroke="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}" StrokeThickness="1" StrokeDashArray="1 2"/>
                        </ControlTemplate>
                    </Setter.Value>
                </Setter>
            </Style>
            <LinearGradientBrush x:Key="ComboBox.Static.Background" EndPoint="0,1" StartPoint="0,0">
                <GradientStop Color="#FFF0F0F0" Offset="0.0"/>
                <GradientStop Color="#FFE5E5E5" Offset="1.0"/>
            </LinearGradientBrush>
            <SolidColorBrush x:Key="ComboBox.Static.Border" Color="#FFACACAC"/>
            <SolidColorBrush x:Key="ComboBox.Static.Editable.Background" Color="#FFFFFFFF"/>
            <SolidColorBrush x:Key="ComboBox.Static.Editable.Border" Color="#FFABADB3"/>
            <SolidColorBrush x:Key="ComboBox.Static.Editable.Button.Background" Color="Transparent"/>
            <SolidColorBrush x:Key="ComboBox.Static.Editable.Button.Border" Color="Transparent"/>
            <SolidColorBrush x:Key="ComboBox.MouseOver.Glyph" Color="#FF000000"/>
            <LinearGradientBrush x:Key="ComboBox.MouseOver.Background" EndPoint="0,1" StartPoint="0,0">
                <GradientStop Color="#FFECF4FC" Offset="0.0"/>
                <GradientStop Color="#FFDCECFC" Offset="1.0"/>
            </LinearGradientBrush>
            <SolidColorBrush x:Key="ComboBox.MouseOver.Border" Color="#FF7EB4EA"/>
            <SolidColorBrush x:Key="ComboBox.MouseOver.Editable.Background" Color="#FFFFFFFF"/>
            <SolidColorBrush x:Key="ComboBox.MouseOver.Editable.Border" Color="#FF7EB4EA"/>
            <LinearGradientBrush x:Key="ComboBox.MouseOver.Editable.Button.Background" EndPoint="0,1" StartPoint="0,0">
                <GradientStop Color="#FFEBF4FC" Offset="0.0"/>
                <GradientStop Color="#FFDCECFC" Offset="1.0"/>
            </LinearGradientBrush>
            <SolidColorBrush x:Key="ComboBox.MouseOver.Editable.Button.Border" Color="#FF7EB4EA"/>
            <SolidColorBrush x:Key="ComboBox.Pressed.Glyph" Color="#FF000000"/>
            <LinearGradientBrush x:Key="ComboBox.Pressed.Background" EndPoint="0,1" StartPoint="0,0">
                <GradientStop Color="#FFDAECFC" Offset="0.0"/>
                <GradientStop Color="#FFC4E0FC" Offset="1.0"/>
            </LinearGradientBrush>
            <SolidColorBrush x:Key="ComboBox.Pressed.Border" Color="#FF569DE5"/>
            <SolidColorBrush x:Key="ComboBox.Pressed.Editable.Background" Color="#FFFFFFFF"/>
            <SolidColorBrush x:Key="ComboBox.Pressed.Editable.Border" Color="#FF569DE5"/>
            <LinearGradientBrush x:Key="ComboBox.Pressed.Editable.Button.Background" EndPoint="0,1" StartPoint="0,0">
                <GradientStop Color="#FFDAEBFC" Offset="0.0"/>
                <GradientStop Color="#FFC4E0FC" Offset="1.0"/>
            </LinearGradientBrush>
            <SolidColorBrush x:Key="ComboBox.Pressed.Editable.Button.Border" Color="#FF569DE5"/>
            <SolidColorBrush x:Key="ComboBox.Disabled.Glyph" Color="#FFBFBFBF"/>
            <SolidColorBrush x:Key="ComboBox.Disabled.Background" Color="#FFF0F0F0"/>
            <SolidColorBrush x:Key="ComboBox.Disabled.Border" Color="#FFD9D9D9"/>
            <SolidColorBrush x:Key="ComboBox.Disabled.Editable.Background" Color="#FFFFFFFF"/>
            <SolidColorBrush x:Key="ComboBox.Disabled.Editable.Border" Color="#FFBFBFBF"/>
            <SolidColorBrush x:Key="ComboBox.Disabled.Editable.Button.Background" Color="Transparent"/>
            <SolidColorBrush x:Key="ComboBox.Disabled.Editable.Button.Border" Color="Transparent"/>
            <SolidColorBrush x:Key="ComboBox.Static.Glyph" Color="#FF606060"/>
            <Style x:Key="ComboBoxToggleButton" TargetType="{x:Type ToggleButton}">
                <Setter Property="OverridesDefaultStyle" Value="true"/>
                <Setter Property="IsTabStop" Value="false"/>
                <Setter Property="Focusable" Value="false"/>
                <Setter Property="ClickMode" Value="Press"/>
                <Setter Property="Template">
                    <Setter.Value>
                        <ControlTemplate TargetType="{x:Type ToggleButton}">
                            <Border x:Name="templateRoot" BorderBrush="{StaticResource ComboBox.Static.Border}" BorderThickness="{TemplateBinding BorderThickness}" Background="{StaticResource ComboBox.Static.Background}" SnapsToDevicePixels="true">
                                <Border x:Name="splitBorder" BorderBrush="Transparent" BorderThickness="1" HorizontalAlignment="Right" Margin="0" SnapsToDevicePixels="true" Width="{DynamicResource {x:Static SystemParameters.VerticalScrollBarWidthKey}}">
                                    <Path x:Name="arrow" Data="F1 M 0,0 L 2.667,2.66665 L 5.3334,0 L 5.3334,-1.78168 L 2.6667,0.88501 L0,-1.78168 L0,0 Z" Fill="{StaticResource ComboBox.Static.Glyph}" HorizontalAlignment="Center" Margin="0" VerticalAlignment="Center"/>
                                </Border>
                            </Border>
                            <ControlTemplate.Triggers>
                                <MultiDataTrigger>
                                    <MultiDataTrigger.Conditions>
                                        <Condition Binding="{Binding IsEditable, RelativeSource={RelativeSource AncestorType={x:Type ComboBox}}}" Value="true"/>
                                        <Condition Binding="{Binding IsMouseOver, RelativeSource={RelativeSource Self}}" Value="false"/>
                                        <Condition Binding="{Binding IsPressed, RelativeSource={RelativeSource Self}}" Value="false"/>
                                        <Condition Binding="{Binding IsEnabled, RelativeSource={RelativeSource Self}}" Value="true"/>
                                    </MultiDataTrigger.Conditions>
                                    <Setter Property="Background" TargetName="templateRoot" Value="{StaticResource ComboBox.Static.Editable.Background}"/>
                                    <Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource ComboBox.Static.Editable.Border}"/>
                                    <Setter Property="Background" TargetName="splitBorder" Value="{StaticResource ComboBox.Static.Editable.Button.Background}"/>
                                    <Setter Property="BorderBrush" TargetName="splitBorder" Value="{StaticResource ComboBox.Static.Editable.Button.Border}"/>
                                </MultiDataTrigger>
                                <Trigger Property="IsMouseOver" Value="true">
                                    <Setter Property="Fill" TargetName="arrow" Value="{StaticResource ComboBox.MouseOver.Glyph}"/>
                                </Trigger>
                                <MultiDataTrigger>
                                    <MultiDataTrigger.Conditions>
                                        <Condition Binding="{Binding IsMouseOver, RelativeSource={RelativeSource Self}}" Value="true"/>
                                        <Condition Binding="{Binding IsEditable, RelativeSource={RelativeSource AncestorType={x:Type ComboBox}}}" Value="false"/>
                                    </MultiDataTrigger.Conditions>
                                    <Setter Property="Background" TargetName="templateRoot" Value="{StaticResource ComboBox.MouseOver.Background}"/>
                                    <Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource ComboBox.MouseOver.Border}"/>
                                </MultiDataTrigger>
                                <MultiDataTrigger>
                                    <MultiDataTrigger.Conditions>
                                        <Condition Binding="{Binding IsMouseOver, RelativeSource={RelativeSource Self}}" Value="true"/>
                                        <Condition Binding="{Binding IsEditable, RelativeSource={RelativeSource AncestorType={x:Type ComboBox}}}" Value="true"/>
                                    </MultiDataTrigger.Conditions>
                                    <Setter Property="Background" TargetName="templateRoot" Value="{StaticResource ComboBox.MouseOver.Editable.Background}"/>
                                    <Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource ComboBox.MouseOver.Editable.Border}"/>
                                    <Setter Property="Background" TargetName="splitBorder" Value="{StaticResource ComboBox.MouseOver.Editable.Button.Background}"/>
                                    <Setter Property="BorderBrush" TargetName="splitBorder" Value="{StaticResource ComboBox.MouseOver.Editable.Button.Border}"/>
                                </MultiDataTrigger>
                                <Trigger Property="IsPressed" Value="true">
                                    <Setter Property="Fill" TargetName="arrow" Value="{StaticResource ComboBox.Pressed.Glyph}"/>
                                </Trigger>
                                <MultiDataTrigger>
                                    <MultiDataTrigger.Conditions>
                                        <Condition Binding="{Binding IsPressed, RelativeSource={RelativeSource Self}}" Value="true"/>
                                        <Condition Binding="{Binding IsEditable, RelativeSource={RelativeSource AncestorType={x:Type ComboBox}}}" Value="false"/>
                                    </MultiDataTrigger.Conditions>
                                    <Setter Property="Background" TargetName="templateRoot" Value="{StaticResource ComboBox.Pressed.Background}"/>
                                    <Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource ComboBox.Pressed.Border}"/>
                                </MultiDataTrigger>
                                <MultiDataTrigger>
                                    <MultiDataTrigger.Conditions>
                                        <Condition Binding="{Binding IsPressed, RelativeSource={RelativeSource Self}}" Value="true"/>
                                        <Condition Binding="{Binding IsEditable, RelativeSource={RelativeSource AncestorType={x:Type ComboBox}}}" Value="true"/>
                                    </MultiDataTrigger.Conditions>
                                    <Setter Property="Background" TargetName="templateRoot" Value="{StaticResource ComboBox.Pressed.Editable.Background}"/>
                                    <Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource ComboBox.Pressed.Editable.Border}"/>
                                    <Setter Property="Background" TargetName="splitBorder" Value="{StaticResource ComboBox.Pressed.Editable.Button.Background}"/>
                                    <Setter Property="BorderBrush" TargetName="splitBorder" Value="{StaticResource ComboBox.Pressed.Editable.Button.Border}"/>
                                </MultiDataTrigger>
                                <Trigger Property="IsEnabled" Value="false">
                                    <Setter Property="Fill" TargetName="arrow" Value="{StaticResource ComboBox.Disabled.Glyph}"/>
                                </Trigger>
                                <MultiDataTrigger>
                                    <MultiDataTrigger.Conditions>
                                        <Condition Binding="{Binding IsEnabled, RelativeSource={RelativeSource Self}}" Value="false"/>
                                        <Condition Binding="{Binding IsEditable, RelativeSource={RelativeSource AncestorType={x:Type ComboBox}}}" Value="false"/>
                                    </MultiDataTrigger.Conditions>
                                    <Setter Property="Background" TargetName="templateRoot" Value="{StaticResource ComboBox.Disabled.Editable.Background}"/>
                                    <Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource ComboBox.Disabled.Editable.Border}"/>
                                </MultiDataTrigger>
                                <MultiDataTrigger>
                                    <MultiDataTrigger.Conditions>
                                        <Condition Binding="{Binding IsEnabled, RelativeSource={RelativeSource Self}}" Value="false"/>
                                        <Condition Binding="{Binding IsEditable, RelativeSource={RelativeSource AncestorType={x:Type ComboBox}}}" Value="true"/>
                                    </MultiDataTrigger.Conditions>
                                    <Setter Property="Background" TargetName="templateRoot" Value="{StaticResource ComboBox.Disabled.Editable.Background}"/>
                                    <Setter Property="BorderBrush" TargetName="templateRoot" Value="{StaticResource ComboBox.Disabled.Editable.Border}"/>
                                    <Setter Property="Background" TargetName="splitBorder" Value="{StaticResource ComboBox.Disabled.Editable.Button.Background}"/>
                                    <Setter Property="BorderBrush" TargetName="splitBorder" Value="{StaticResource ComboBox.Disabled.Editable.Button.Border}"/>
                                </MultiDataTrigger>
                            </ControlTemplate.Triggers>
                        </ControlTemplate>
                    </Setter.Value>
                </Setter>
            </Style>
            <ControlTemplate x:Key="ComboBoxTemplate" TargetType="{x:Type ComboBox}">
                <Grid x:Name="templateRoot" 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, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Margin="1" PopupAnimation="{DynamicResource {x:Static SystemParameters.ComboBoxPopupAnimationKey}}" Placement="Bottom">
                        <Themes:SystemDropShadowChrome x:Name="shadow" Color="Transparent" MaxHeight="{TemplateBinding MaxDropDownHeight}" MinWidth="{Binding ActualWidth, ElementName=templateRoot}">
                            <Border x:Name="dropDownBorder" BorderBrush="{DynamicResource {x:Static SystemColors.WindowFrameBrushKey}}" BorderThickness="1" Background="{DynamicResource {x:Static SystemColors.WindowBrushKey}}">
                                <ScrollViewer x:Name="DropDownScrollViewer">
                                    <Grid x:Name="grid" RenderOptions.ClearTypeHint="Enabled">
                                        <Canvas x:Name="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}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Grid.ColumnSpan="2" IsChecked="{Binding IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource ComboBoxToggleButton}"/>
                    <ContentPresenter x:Name="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="HasDropShadow" SourceName="PART_Popup" Value="true">
                        <Setter Property="Margin" TargetName="shadow" Value="0,0,5,5"/>
                        <Setter Property="Color" TargetName="shadow" Value="#71000000"/>
                    </Trigger>
                    <Trigger Property="HasItems" Value="false">
                        <Setter Property="Height" TargetName="dropDownBorder" Value="95"/>
                    </Trigger>
                    <MultiTrigger>
                        <MultiTrigger.Conditions>
                            <Condition Property="IsGrouping" Value="true"/>
                            <Condition Property="VirtualizingPanel.IsVirtualizingWhenGrouping" Value="false"/>
                        </MultiTrigger.Conditions>
                        <Setter Property="ScrollViewer.CanContentScroll" Value="false"/>
                    </MultiTrigger>
                    <Trigger Property="ScrollViewer.CanContentScroll" SourceName="DropDownScrollViewer" Value="false">
                        <Setter Property="Canvas.Top" TargetName="opaqueRect" Value="{Binding VerticalOffset, ElementName=DropDownScrollViewer}"/>
                        <Setter Property="Canvas.Left" TargetName="opaqueRect" Value="{Binding HorizontalOffset, ElementName=DropDownScrollViewer}"/>
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
            <SolidColorBrush x:Key="TextBox.Static.Background" Color="#FFFFFFFF"/>
            <Style x:Key="ComboBoxEditableTextBox" TargetType="{x:Type TextBox}">
                <Setter Property="OverridesDefaultStyle" Value="true"/>
                <Setter Property="AllowDrop" Value="true"/>
                <Setter Property="MinWidth" Value="0"/>
                <Setter Property="MinHeight" Value="0"/>
                <Setter Property="FocusVisualStyle" Value="{x:Null}"/>
                <Setter Property="ScrollViewer.PanningMode" Value="VerticalFirst"/>
                <Setter Property="Stylus.IsFlicksEnabled" Value="False"/>
                <Setter Property="Template">
                    <Setter.Value>
                        <ControlTemplate TargetType="{x:Type TextBox}">
                            <ScrollViewer x:Name="PART_ContentHost" Background="Transparent" Focusable="false" HorizontalScrollBarVisibility="Hidden" VerticalScrollBarVisibility="Hidden"/>
                        </ControlTemplate>
                    </Setter.Value>
                </Setter>
            </Style>
            <ControlTemplate x:Key="ComboBoxEditableTemplate" TargetType="{x:Type ComboBox}">
                <Grid x:Name="templateRoot" 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}}" PopupAnimation="{DynamicResource {x:Static SystemParameters.ComboBoxPopupAnimationKey}}" Placement="Bottom">
                        <Themes:SystemDropShadowChrome x:Name="shadow" Color="Transparent" MaxHeight="{TemplateBinding MaxDropDownHeight}" MinWidth="{Binding ActualWidth, ElementName=templateRoot}">
                            <Border x:Name="dropDownBorder" BorderBrush="{DynamicResource {x:Static SystemColors.WindowFrameBrushKey}}" BorderThickness="1" Background="{DynamicResource {x:Static SystemColors.WindowBrushKey}}">
                                <ScrollViewer x:Name="DropDownScrollViewer">
                                    <Grid x:Name="grid" RenderOptions.ClearTypeHint="Enabled">
                                        <Canvas x:Name="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}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Grid.ColumnSpan="2" IsChecked="{Binding IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource ComboBoxToggleButton}"/>
                    <Border x:Name="border" Background="{StaticResource TextBox.Static.Background}" Margin="{TemplateBinding BorderThickness}">
                        <TextBox x:Name="PART_EditableTextBox" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" IsReadOnly="{Binding IsReadOnly, RelativeSource={RelativeSource TemplatedParent}}" Margin="{TemplateBinding Padding}" Style="{StaticResource ComboBoxEditableTextBox}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"/>
                    </Border>
                </Grid>
                <ControlTemplate.Triggers>
                    <Trigger Property="IsEnabled" Value="false">
                        <Setter Property="Opacity" TargetName="border" Value="0.56"/>
                    </Trigger>
                    <Trigger Property="IsKeyboardFocusWithin" Value="true">
                        <Setter Property="Foreground" Value="Black"/>
                    </Trigger>
                    <Trigger Property="HasDropShadow" SourceName="PART_Popup" Value="true">
                        <Setter Property="Margin" TargetName="shadow" Value="0,0,5,5"/>
                        <Setter Property="Color" TargetName="shadow" Value="#71000000"/>
                    </Trigger>
                    <Trigger Property="HasItems" Value="false">
                        <Setter Property="Height" TargetName="dropDownBorder" Value="95"/>
                    </Trigger>
                    <MultiTrigger>
                        <MultiTrigger.Conditions>
                            <Condition Property="IsGrouping" Value="true"/>
                            <Condition Property="VirtualizingPanel.IsVirtualizingWhenGrouping" Value="false"/>
                        </MultiTrigger.Conditions>
                        <Setter Property="ScrollViewer.CanContentScroll" Value="false"/>
                    </MultiTrigger>
                    <Trigger Property="ScrollViewer.CanContentScroll" SourceName="DropDownScrollViewer" Value="false">
                        <Setter Property="Canvas.Top" TargetName="opaqueRect" Value="{Binding VerticalOffset, ElementName=DropDownScrollViewer}"/>
                        <Setter Property="Canvas.Left" TargetName="opaqueRect" Value="{Binding HorizontalOffset, ElementName=DropDownScrollViewer}"/>
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
            <Style TargetType="{x:Type ComboBox}">
                <Setter Property="FocusVisualStyle" Value="{StaticResource FocusVisual}"/>
                <Setter Property="Background" Value="{StaticResource ComboBox.Static.Background}"/>
                <Setter Property="BorderBrush" Value="{StaticResource ComboBox.Static.Border}"/>
                <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.WindowTextBrushKey}}"/>
                <Setter Property="BorderThickness" Value="1"/>
                <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto"/>
                <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto"/>
                <Setter Property="Padding" Value="6,3,5,3"/>
                <Setter Property="ScrollViewer.CanContentScroll" Value="true"/>
                <Setter Property="ScrollViewer.PanningMode" Value="Both"/>
                <Setter Property="Stylus.IsFlicksEnabled" Value="False"/>
                <Setter Property="Template" Value="{StaticResource ComboBoxTemplate}"/>
                <Style.Triggers>
                    <Trigger Property="IsEditable" Value="true">
                        <Setter Property="IsTabStop" Value="false"/>
                        <Setter Property="Padding" Value="2"/>
                        <Setter Property="Template" Value="{StaticResource ComboBoxEditableTemplate}"/>
                    </Trigger>
                    <MultiTrigger>
                        <MultiTrigger.Conditions>
                            <Condition Property="IsEnabled" Value="false" />
                            <Condition Property="IsEditable" Value="false" />
                        </MultiTrigger.Conditions>
                        <MultiTrigger.Setters>
                            <Setter Property="Foreground" Value="Gray" />
                        </MultiTrigger.Setters>
                    </MultiTrigger>
                </Style.Triggers>
            </Style>
        </ResourceDictionary>
    </Window.Resources>

    <StackPanel>
        <ComboBox Width="150" 
                  Height="23" 
                  SelectedIndex="0" 
                  IsEnabled="{Binding IsChecked, ElementName=isEnabledCheckBox}"
                  IsEditable="{Binding IsChecked, ElementName=isEditableCheckBox}">
            <TextBlock><Run Text="Hello"/></TextBlock>
            <TextBlock><Run Text="World"/></TextBlock>
        </ComboBox>

        <CheckBox x:Name="isEnabledCheckBox" Content="IsEnabled" />
        <CheckBox x:Name="isEditableCheckBox" Content="IsEditable" />
    </StackPanel>
</Window>

Answer 3

禁用的TextBlock不会更改前景色。您可以使用以下标记轻松确认：

<TextBlock Text="test" IsEnabled="False" />

您可以通过使用TextBlock定义DataTrigger样式来“修复”此问题。这应该有效：

<ComboBox Width="150" Height="23" IsEnabled="False" SelectedIndex="0">
    <ComboBox.Resources>
        <Style TargetType="TextBlock">
            <Style.Triggers>
                <DataTrigger Binding="{Binding IsEnabled, RelativeSource={RelativeSource AncestorType=ComboBox}}" Value="False">
                    <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}" />
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </ComboBox.Resources>
    <TextBlock>Hello</TextBlock>
    <TextBlock>World</TextBlock>
</ComboBox>