如何更改组合框中的占位符文本颜色

Question

我一直在努力寻找这个解决方案。我将在下面发布相同的内容，这可能会为任何尝试此操作的人节省几个小时。

Answer 1

右击设计器开始编辑模板。

ComboBox 默认行为是 -> 如果少于 5 个项目，则它是一个下拉菜单，否则，选项显示在单独的页面上以供选择。

以下是自定义ComboBox的编辑样式——“ComboBoxStyle1”

我在下面做了3处更改（在代码sn-p中搜索颜色）

Foreground="Red" - 在 "options

Foreground="PowderBlue" 在“options > 5”时改变 PlaceHolderText 颜色

ForeGround="Black" - 如果“选项 > 5”，我们点击组合框并按返回键 - 故事板将占位符文本颜色更改回默认值。为了限制这一点，我们可以使用这个位置来设置我们的颜色。

<SolidColorBrush x:Key="ComboBoxBackgroundThemeBrush" Color="Transparent"/>
<Thickness x:Key="ComboBoxBorderThemeThickness">2.5</Thickness>
<FontFamily x:Key="PhoneFontFamilyNormal">Segoe WP</FontFamily>
<x:Double x:Key="ContentControlFontSize">20.26</x:Double>
<x:Double x:Key="ComboBoxItemMinHeightThemeSize">33.5</x:Double>
<Thickness x:Key="ComboBoxPlaceholderTextThemeMargin">6.5,0.8</Thickness>
<Thickness x:Key="PhoneTouchTargetOverhang">0,9.5</Thickness>
<SolidColorBrush x:Key="ComboBoxDisabledBackgroundThemeBrush" Color="Transparent"/>
<Style x:Key="ComboBoxStyle1" TargetType="ComboBox">
    <Setter Property="Foreground" Value="{ThemeResource ComboBoxForegroundThemeBrush}"/>
    <Setter Property="Background" Value="{ThemeResource ComboBoxBackgroundThemeBrush}"/>
    <Setter Property="BorderBrush" Value="{ThemeResource ComboBoxBorderThemeBrush}"/>
    <Setter Property="BorderThickness" Value="{ThemeResource ComboBoxBorderThemeThickness}"/>
    <Setter Property="HorizontalContentAlignment" Value="Left"/>
    <Setter Property="FontFamily" Value="{ThemeResource PhoneFontFamilyNormal}"/>
    <Setter Property="FontSize" Value="{ThemeResource ContentControlFontSize}"/>
    <Setter Property="Margin" Value="0"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="ComboBox">
                <Grid x:Name="ComboBoxGrid">
                    <Grid.RowDefinitions>
                        <RowDefinition Height="Auto"/>
                        <RowDefinition Height="Auto"/>
                    </Grid.RowDefinitions>
                    <VisualStateManager.VisualStateGroups>
                        <VisualStateGroup x:Name="CommonStates">
                            <VisualStateGroup.Transitions>
                                <VisualTransition From="Pressed" To="PointerOver">
                                    <Storyboard>
                                        <PointerUpThemeAnimation Storyboard.TargetName="Background"/>
                                    </Storyboard>
                                </VisualTransition>
                                <VisualTransition From="PointerOver" To="Normal">
                                    <Storyboard>
                                        <PointerUpThemeAnimation Storyboard.TargetName="Background"/>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="PlaceholderTextBlock">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="Black"/>
                                        </ObjectAnimationUsingKeyFrames>
                                        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PlaceholderTextBlock">
                                            <DiscreteObjectKeyFrame KeyTime="0" Value="1"/>
                                        </ObjectAnimationUsingKeyFrames>
                                    </Storyboard>
                                </VisualTransition>
                                <VisualTransition From="Pressed" To="Normal">
                                    <Storyboard>
                                        <PointerUpThemeAnimation Storyboard.TargetName="Background"/>
                                    </Storyboard>
                                </VisualTransition>
                            </VisualStateGroup.Transitions>
                            <VisualState x:Name="Normal">
                                <Storyboard>
                                    <DoubleAnimation Duration="0" To="{ThemeResource ComboBoxFlyoutListPlaceholderTextOpacity}" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PlaceholderTextBlock"/>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="PointerOver"/>
                            <VisualState x:Name="Pressed">
                                <Storyboard>
                                    <PointerDownThemeAnimation Storyboard.TargetName="Background"/>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="Background">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxPressedBackgroundThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="Background">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxPressedBorderThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="UserControl">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxPressedForegroundThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Highlighted">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="Background">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxHighlightedBackgroundThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="Background">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxHighlightedBorderThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="UserControl">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxHighlightedForegroundThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Disabled">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="HeaderContentPresenter">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxDisabledForegroundThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentPresenter">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxDisabledForegroundThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="Background">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxDisabledBackgroundThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="Background">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxDisabledBorderThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="FlyoutButton">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxDisabledBorderThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="UserControl">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxDisabledForegroundThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="PlaceholderTextBlock">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxDisabledForegroundThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PlaceholderTextBlock"/>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="PlaceholderTextContentPresenter">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxDisabledForegroundThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                        </VisualStateGroup>
                        <VisualStateGroup x:Name="DropDownStates">
                            <VisualState x:Name="Opened">
                                <Storyboard>
                                    <DoubleAnimation Duration="0:0:0.25" EnableDependentAnimation="True" From="{Binding TemplateSettings.DropDownClosedHeight, RelativeSource={RelativeSource Mode=TemplatedParent}}" To="{Binding TemplateSettings.DropDownOpenedHeight, RelativeSource={RelativeSource Mode=TemplatedParent}}" Storyboard.TargetProperty="Height" Storyboard.TargetName="ItemsPresenterHost">
                                        <DoubleAnimation.EasingFunction>
                                            <ExponentialEase EasingMode="EaseInOut" Exponent="6"/>
                                        </DoubleAnimation.EasingFunction>
                                    </DoubleAnimation>
                                    <DoubleAnimation Duration="0:0:0.25" To="{Binding TemplateSettings.DropDownOffset, RelativeSource={RelativeSource Mode=TemplatedParent}}" Storyboard.TargetProperty="Y" Storyboard.TargetName="ItemsPresenterTranslateTransform">
                                        <DoubleAnimation.EasingFunction>
                                            <ExponentialEase EasingMode="EaseInOut" Exponent="6"/>
                                        </DoubleAnimation.EasingFunction>
                                    </DoubleAnimation>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="IsHitTestVisible" Storyboard.TargetName="UserControl">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="True"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="Background">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxHighlightedBackgroundThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="UserControl">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxHighlightedForegroundThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Closed">
                                <Storyboard>
                                    <DoubleAnimation Duration="0:0:0.2" EnableDependentAnimation="True" From="{Binding TemplateSettings.DropDownOpenedHeight, RelativeSource={RelativeSource Mode=TemplatedParent}}" To="{Binding TemplateSettings.DropDownClosedHeight, RelativeSource={RelativeSource Mode=TemplatedParent}}" Storyboard.TargetProperty="Height" Storyboard.TargetName="ItemsPresenterHost">
                                        <DoubleAnimation.EasingFunction>
                                            <ExponentialEase EasingMode="EaseInOut" Exponent="6"/>
                                        </DoubleAnimation.EasingFunction>
                                    </DoubleAnimation>
                                    <DoubleAnimation Duration="0:0:0.2" To="{Binding TemplateSettings.DropDownOffset, RelativeSource={RelativeSource Mode=TemplatedParent}}" Storyboard.TargetProperty="Y" Storyboard.TargetName="ItemsPresenterTranslateTransform">
                                        <DoubleAnimation.EasingFunction>
                                            <ExponentialEase EasingMode="EaseInOut" Exponent="6"/>
                                        </DoubleAnimation.EasingFunction>
                                    </DoubleAnimation>
                                </Storyboard>
                            </VisualState>
                        </VisualStateGroup>
                        <VisualStateGroup x:Name="PresenterStates">
                            <VisualState x:Name="Full"/>
                            <VisualState x:Name="InlineNormal">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="FlyoutButton">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="Collapsed"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="ShortListOuterBorder">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="Visible"/>
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="InlinePlaceholder">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="FlyoutButton">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="Collapsed"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="ShortListOuterBorder">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="Visible"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <DoubleAnimation Duration="0" To="1" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PlaceholderTextContentPresenter"/>
                                    <DoubleAnimation Duration="0" To="0" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="ItemsPresenter"/>
                                </Storyboard>
                            </VisualState>
                        </VisualStateGroup>
                    </VisualStateManager.VisualStateGroups>
                    <ContentPresenter x:Name="HeaderContentPresenter" ContentTemplate="{TemplateBinding HeaderTemplate}" Content="{TemplateBinding Header}" FlowDirection="{TemplateBinding FlowDirection}" HorizontalAlignment="Left" Margin="0,0,0,-4.5" Style="{StaticResource HeaderContentPresenterStyle}" Visibility="Collapsed"/>
                    <Button x:Name="FlyoutButton" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" FontWeight="Normal" FlowDirection="{TemplateBinding FlowDirection}" FontSize="{ThemeResource ContentControlFontSize}" HorizontalAlignment="Stretch" HorizontalContentAlignment="Left" MinHeight="{ThemeResource ComboBoxItemMinHeightThemeSize}" Padding="6.5,0,0,0" Grid.Row="1">
                        <ContentPresenter x:Name="ContentPresenter" Margin="0,0.8,0,0" MinHeight="32.5">
                            <TextBlock x:Name="PlaceholderTextBlock" Margin="0" IsColorFontEnabled="True" Style="{StaticResource ComboBoxPlaceholderTextBlockStyle}" Text="{TemplateBinding PlaceholderText}" Foreground="Red"/>
                        </ContentPresenter>
                    </Button>
                    <Border x:Name="ShortListOuterBorder" Margin="{ThemeResource PhoneTouchTargetOverhang}" Grid.Row="1" Visibility="Collapsed">
                        <Border x:Name="Background" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}">
                            <UserControl x:Name="UserControl" Foreground="{TemplateBinding Foreground}" FlowDirection="{TemplateBinding FlowDirection}" IsHitTestVisible="False">
                                <Canvas x:Name="ItemsPresenterHost" HorizontalAlignment="Left" MinHeight="{ThemeResource ComboBoxItemMinHeightThemeSize}">
                                    <ContentPresenter x:Name="PlaceholderTextContentPresenter" Content="{TemplateBinding PlaceholderText}" Margin="{ThemeResource ComboBoxPlaceholderTextThemeMargin}" Opacity="0" Style="{StaticResource PlaceholderContentPresenterStyle}" Foreground="PowderBlue"/>
                                    <ItemsPresenter x:Name="ItemsPresenter" Margin="0,0.8,0,0">
                                        <ItemsPresenter.RenderTransform>
                                            <TranslateTransform x:Name="ItemsPresenterTranslateTransform"/>
                                        </ItemsPresenter.RenderTransform>
                                    </ItemsPresenter>
                                </Canvas>
                            </UserControl>
                        </Border>
                    </Border>
                </Grid>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>