我的 WindowsPhone 8.1 运行时应用程序需要透明文本框。

我为文本框设置了Background="Transparent"，所以它在加载时是透明的。

但聚焦时，背景颜色变为白色。我写了下面的代码，让它透明。但是它没有运行。!

<TextBox Background="Transparent" GotFocus="titleBox_GotFocus" />

C#

private void titleBox_GotFocus(object sender, RoutedEventArgs e)
{
    titleBox.Background = new SolidColorBrush(Colors.Transparent);
}

最佳答案

问题是，当您的 TextBox 获得焦点时，StoryBoard 会将 Background 更改为 ThemeResource - 默认情况下，TExtBox 旨在执行此操作。当然，您可以更改它 - 因为您的目标是 WP8.1 运行时，所以您将不得不使用 TextBox 的 VisualStaes。多说一句，你将不得不改变Focused状态:

<VisualState x:Name="Focused">
    <Storyboard>
        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="BorderElement">
            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextSelectionHighlightColorThemeBrush}"/>
        </ObjectAnimationUsingKeyFrames>
        <DoubleAnimation Duration="0" To="0" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PlaceholderTextContentPresenter"/>
        <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="BackgroundElement">
            <DiscreteObjectKeyFrame KeyTime="0" Value="Transparent"/>
        </ObjectAnimationUsingKeyFrames>
    </Storyboard>
</VisualState>

在上面的代码中，我更改了第三个动画，所以现在它将 Transparent 设置为 Background。

完整的样式(取自 Blend)如下所示:

<Page.Resources>
<Style x:Key="TransparentStyle" TargetType="TextBox">
    <Setter Property="MinWidth" Value="{ThemeResource TextControlThemeMinWidth}"/>
    <Setter Property="MinHeight" Value="{ThemeResource TextControlThemeMinHeight}"/>
    <Setter Property="Foreground" Value="{ThemeResource TextBoxForegroundThemeBrush}"/>
    <Setter Property="SelectionHighlightColor" Value="{ThemeResource TextSelectionHighlightColorThemeBrush}"/>
    <Setter Property="Background" Value="{ThemeResource TextBoxBackgroundThemeBrush}"/>
    <Setter Property="BorderBrush" Value="{ThemeResource TextBoxBorderThemeBrush}"/>
    <Setter Property="BorderThickness" Value="{ThemeResource TextControlBorderThemeThickness}"/>
    <Setter Property="FontFamily" Value="{ThemeResource PhoneFontFamilyNormal}"/>
    <Setter Property="FontSize" Value="{ThemeResource ContentControlFontSize}"/>
    <Setter Property="TextWrapping" Value="NoWrap"/>
    <Setter Property="ScrollViewer.HorizontalScrollMode" Value="Auto"/>
    <Setter Property="ScrollViewer.VerticalScrollMode" Value="Auto"/>
    <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Hidden"/>
    <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Hidden"/>
    <Setter Property="ScrollViewer.IsDeferredScrollingEnabled" Value="False"/>
    <Setter Property="Padding" Value="{ThemeResource TextControlThemePadding}"/>
    <Setter Property="Margin" Value="{ThemeResource TextControlMarginThemeThickness}"/>
    <Setter Property="VerticalAlignment" Value="Top"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="TextBox">
                <Grid>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="Auto"/>
                        <RowDefinition Height="*"/>
                    </Grid.RowDefinitions>
                    <VisualStateManager.VisualStateGroups>
                        <VisualStateGroup x:Name="CommonStates">
                            <VisualState x:Name="Disabled">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="BackgroundElement">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxDisabledBackgroundThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="BorderElement">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxDisabledBorderThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentElement">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxDisabledForegroundThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="PlaceholderTextContentPresenter">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxDisabledForegroundThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Normal">
                                <Storyboard>
                                    <DoubleAnimation Duration="0" To="{ThemeResource TextControlBackgroundThemeOpacity}" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="BackgroundElement"/>
                                    <DoubleAnimation Duration="0" To="{ThemeResource TextControlBorderThemeOpacity}" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="BorderElement"/>
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Focused">
                                <Storyboard>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="BorderElement">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextSelectionHighlightColorThemeBrush}"/>
                                    </ObjectAnimationUsingKeyFrames>
                                    <DoubleAnimation Duration="0" To="0" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PlaceholderTextContentPresenter"/>
                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="BackgroundElement">
                                        <DiscreteObjectKeyFrame KeyTime="0" Value="Transparent"/>
                                    </ObjectAnimationUsingKeyFrames>
                                </Storyboard>
                            </VisualState>
                        </VisualStateGroup>
                    </VisualStateManager.VisualStateGroups>
                    <Border x:Name="BackgroundElement" Background="{TemplateBinding Background}" Margin="{TemplateBinding BorderThickness}" Grid.Row="1"/>
                    <Border x:Name="BorderElement" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Grid.Row="1"/>
                    <ContentPresenter x:Name="HeaderContentPresenter" ContentTemplate="{TemplateBinding HeaderTemplate}" Content="{TemplateBinding Header}" Margin="{ThemeResource TextControlHeaderMarginThemeThickness}" Grid.Row="0" Style="{StaticResource HeaderContentPresenterStyle}"/>
                    <ScrollViewer x:Name="ContentElement" AutomationProperties.AccessibilityView="Raw" HorizontalScrollMode="{TemplateBinding ScrollViewer.HorizontalScrollMode}" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" IsTabStop="False" IsHorizontalRailEnabled="{TemplateBinding ScrollViewer.IsHorizontalRailEnabled}" IsVerticalRailEnabled="{TemplateBinding ScrollViewer.IsVerticalRailEnabled}" IsDeferredScrollingEnabled="{TemplateBinding ScrollViewer.IsDeferredScrollingEnabled}" Margin="{TemplateBinding BorderThickness}" MinHeight="{ThemeResource TextControlThemeMinHeight}" Padding="{TemplateBinding Padding}" Grid.Row="1" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" VerticalScrollMode="{TemplateBinding ScrollViewer.VerticalScrollMode}" ZoomMode="Disabled"/>
                    <ContentControl x:Name="PlaceholderTextContentPresenter" Content="{TemplateBinding PlaceholderText}" Foreground="{ThemeResource TextBoxPlaceholderTextThemeBrush}" FontSize="{ThemeResource ContentControlFontSize}" IsTabStop="False" Margin="{TemplateBinding BorderThickness}" Padding="{TemplateBinding Padding}" Grid.Row="1"/>
                </Grid>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>
</Page.Resources>

然后你像这样使用它:

<TextBox Background="Transparent" GotFocus="titleBox_GotFocus" Style="{StaticResource TransparentStyle}"/>

关于c# - 文本框 GotFocussed Windows Phone 8.1 时透明文本框？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/24033571/