【发布时间】：2011-08-08 10:10:10
【问题描述】：
我已经发现了很多关于在组合框的下拉列表中操作要选择的项目的突出显示或覆盖系统画笔的问题。这不是我想要的。我想摆脱选择后组合框文本字段中显示的所选项目的文本突出显示。但我不想摆脱下拉菜单中突出显示的文本！所以覆盖系统画笔不是我需要的，因为这也会影响下拉列表中的项目。下面是完整测试项目的 XAML。构建 + 运行并选择一个项目以查看效果。组合框文本字段中任何选定项目的文本将用浅灰色画笔突出显示。这就是我想摆脱的..但是如何..？
<Window.Resources>
<Style x:Key="ComboboxDropdownButton" TargetType="{x:Type ToggleButton}">
<Setter Property="MinWidth" Value="0"/>
<Setter Property="MinHeight" Value="0"/>
<Setter Property="Width" Value="NaN"/>
<Setter Property="Height" Value="NaN"/>
<Setter Property="Background" Value="Transparent"/>
<Setter Property="BorderBrush" Value="Black"/>
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ToggleButton}">
<DockPanel SnapsToDevicePixels="True"
Background="{TemplateBinding Background}"
LastChildFill="False">
<Border x:Name="Border"
Width="{DynamicResource {x:Static SystemParameters.VerticalScrollBarWidthKey}}"
DockPanel.Dock="Right"
Background="WhiteSmoke"
CornerRadius="0,3,3,0"
BorderThickness="{TemplateBinding BorderThickness}"
BorderBrush="{TemplateBinding BorderBrush}"
>
<Path Fill="{TemplateBinding Foreground}" HorizontalAlignment="Center" VerticalAlignment="Center" Data="M0,0L4.5,4 9,0z"/>
</Border>
</DockPanel>
<ControlTemplate.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter TargetName="Border" Property="Background" Value="White" />
</Trigger>
<Trigger Property="IsChecked" Value="True">
<Setter TargetName="Border" Property="Background" Value="White" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Opacity" Value="0.5"/>
</Trigger>
</Style.Triggers>
</Style>
<ControlTemplate x:Key="ComboBoxTextBox" TargetType="{x:Type TextBox}">
<Border x:Name="PART_ContentHost" Focusable="False" />
</ControlTemplate>
<Style x:Key="{x:Type ComboBox}" TargetType="{x:Type ComboBox}">
<Setter Property="SnapsToDevicePixels" Value="true" />
<Setter Property="OverridesDefaultStyle" Value="true" />
<Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto" />
<Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto" />
<Setter Property="ScrollViewer.CanContentScroll" Value="true" />
<Setter Property="MinWidth" Value="120" />
<Setter Property="MinHeight" Value="20" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ComboBox}">
<Grid>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="EditStates">
<VisualState x:Name="Editable">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Visibility)"
Storyboard.TargetName="PART_EditableTextBox">
<DiscreteObjectKeyFrame KeyTime="0" Value="{x:Static Visibility.Visible}" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Uneditable" />
</VisualStateGroup>
<VisualStateGroup x:Name="FocusStates">
<VisualState x:Name="Focused">
<Storyboard>
<DoubleAnimation Duration="00:00:00" Storyboard.TargetName="FocusVisualElement" Storyboard.TargetProperty="(UIElement.Opacity)" To="1"/>
</Storyboard>
</VisualState>
<VisualState x:Name="Unfocused"/>
<VisualState x:Name="FocusedDropDown">
<Storyboard>
<ObjectAnimationUsingKeyFrames Duration="00:00:00" Storyboard.TargetName="DropDownBorder" Storyboard.TargetProperty="(UIElement.Visibility)">
<DiscreteObjectKeyFrame KeyTime="00:00:00">
<DiscreteObjectKeyFrame.Value>
<Visibility>Visible</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<ToggleButton x:Name="ToggleButton"
Margin="-1"
Grid.Column="2"
Focusable="False"
ClickMode="Press"
Style="{StaticResource ComboboxDropdownButton}"
IsChecked="{Binding IsDropDownOpen, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}">
</ToggleButton>
<TextBox x:Name="PART_EditableTextBox"
Style="{x:Null}"
Template="{StaticResource ComboBoxTextBox}"
HorizontalAlignment="Left"
VerticalAlignment="Bottom"
Margin="3,3,23,3"
Focusable="True"
Background="Transparent"
Visibility="Hidden"
IsReadOnly="{TemplateBinding IsReadOnly}" />
<Rectangle x:Name="FocusVisualElement" RadiusX="2" RadiusY="2" Margin="-3" Stroke="Red" StrokeThickness="1" Opacity="0" IsHitTestVisible="false" />
<Rectangle x:Name="BackgroundVisualElement" RadiusX="2" RadiusY="2" Margin="-1" Fill="BlanchedAlmond" Panel.ZIndex="-1" Stroke="Black" StrokeThickness="1" IsHitTestVisible="false" />
<Popup x:Name="PART_Popup"
Placement="Bottom"
IsOpen="{TemplateBinding IsDropDownOpen}"
AllowsTransparency="True"
Focusable="False"
PopupAnimation="Slide">
<Border x:Name="DropDownBorder"
MaxHeight="{TemplateBinding MaxDropDownHeight}"
MinWidth="{Binding ActualWidth, ElementName=BackgroundVisualElement}"
Background="BlanchedAlmond"
BorderBrush="Black"
BorderThickness="1" CornerRadius="0,0,3,3">
<ScrollViewer>
<ItemsPresenter KeyboardNavigation.DirectionalNavigation="Contained" />
</ScrollViewer>
</Border>
</Popup>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="HasItems" Value="false">
<Setter TargetName="DropDownBorder" Property="MinHeight" Value="95" />
</Trigger>
<Trigger Property="IsGrouping" Value="true">
<Setter Property="ScrollViewer.CanContentScroll" Value="false" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Window.Resources>
<Grid>
<Button Margin="0,0,363,221" />
<ComboBox Width="120" Height="20" Name="comboBox1" SnapsToDevicePixels="True" HorizontalAlignment="Center" VerticalAlignment="Center" SelectedIndex="0" IsEditable="True" IsReadOnly="True">
<ComboBoxItem>item 1</ComboBoxItem>
<ComboBoxItem>item 2</ComboBoxItem>
<ComboBoxItem>item 3</ComboBoxItem>
</ComboBox>
</Grid>
</Window>
编辑：为获得更好的效果，请将 Foreground="Transparent" 添加到 PART_EditableTextBox。组合框文本字段中的选定项目仍会以我想摆脱的浅灰色画笔突出显示..
【问题讨论】：