Question

我正在UWP应用程序中使用RichEditBox，并且需要在软件中启用和禁用它才能执行某些任务。我遇到的问题是，当我禁用然后重新启用它时，所有颜色格式都会丢失。我在这里创建了一个简单的示例，以尝试解决该问题。您可以键入一些文本，将其涂成红色，然后禁用并重新启用。颜色恢复为黑色。

XAML

<StackPanel>
    <StackPanel Orientation="Horizontal">
        <Button Content="Disable" Click="OnDisable"/>
        <Button Content="Enable" Click="OnEnable"/>
        <Button Content="Red" Click="OnRed"/>
    </StackPanel>
    <RichEditBox Name="RichEditor" Width="500" Height="200"/>
</StackPanel>

C＃

private void OnDisable(object sender, RoutedEventArgs e)
{
    RichEditor.IsEnabled = false;
}

private void OnEnable(object sender, RoutedEventArgs e)
{
    RichEditor.IsEnabled = true;
}

private void OnRed(object sender, RoutedEventArgs e)
{
     RichEditor.Document.Selection.CharacterFormat.ForegroundColor = Colors.Red;
}

这看起来像RichEditBox组件中的错误，我想知道是否有人可以通过一种变通办法来启用和禁用文本而不会丢失颜色格式。在示例下面重现问题。

Answer 1

请参阅Control style and template类中的RichEditBox部分：

您可以修改默认的Style和ControlTemplate以使控件具有唯一的外观。generic.xaml文件中包含定义控件外观的默认样式，模板和资源。出于设计目的，Windows软件开发工具包（SDK）安装中的（程序文件）\ Windows Kits \ 10 \ DesignTime \ CommonConfiguration \ Neutral \ UAP \ Generic文件夹中提供了generic.xaml。来自不同版本的SDK的样式和资源可能具有不同的值。

因此，您可以找到 System.Windows.Controls.RichEditBox 控件的默认样式，这是版本1803上的默认样式目标：

<!-- Default style for System.Windows.Controls.RichEditBox -->
        <Style TargetType="RichEditBox">
            <Setter Property="MinWidth" Value="{ThemeResource TextControlThemeMinWidth}" />
            <Setter Property="MinHeight" Value="{ThemeResource TextControlThemeMinHeight}" />
            <Setter Property="Foreground" Value="{ThemeResource TextControlForeground}" />
            <Setter Property="Background" Value="{ThemeResource TextControlBackground}" />
            <Setter Property="ContentLinkForegroundColor" Value="{ThemeResource ContentLinkForegroundColor}" />
            <Setter Property="ContentLinkBackgroundColor" Value="{ThemeResource ContentLinkBackgroundColor}" />
            <Setter Property="SelectionHighlightColor" Value="{ThemeResource TextControlSelectionHighlightColor}" />
            <Setter Property="BorderBrush" Value="{ThemeResource TextControlBorderBrush}" />
            <Setter Property="BorderThickness" Value="{ThemeResource TextControlBorderThemeThickness}" />
            <Setter Property="FontFamily" Value="{ThemeResource ContentControlThemeFontFamily}" />
            <Setter Property="FontSize" Value="{ThemeResource ControlContentThemeFontSize}" />
            <Setter Property="ScrollViewer.HorizontalScrollMode" Value="Auto" />
            <Setter Property="ScrollViewer.VerticalScrollMode" Value="Auto" />
            <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto" />
            <Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto" />
            <Setter Property="ScrollViewer.IsDeferredScrollingEnabled" Value="False" />
            <Setter Property="TextWrapping" Value="Wrap" />
            <Setter Property="Padding" Value="{ThemeResource TextControlThemePadding}" />
            <Setter Property="UseSystemFocusVisuals" Value="{ThemeResource IsApplicationFocusVisualKindReveal}" />
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="RichEditBox">
                        <Grid>

                            <VisualStateManager.VisualStateGroups>
                                <VisualStateGroup x:Name="CommonStates">

                                    <VisualState x:Name="Disabled">

                                        <Storyboard>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="HeaderContentPresenter" Storyboard.TargetProperty="Foreground">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlHeaderForegroundDisabled}" />
                                            </ObjectAnimationUsingKeyFrames>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="BorderElement" Storyboard.TargetProperty="Background">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlBackgroundDisabled}" />
                                            </ObjectAnimationUsingKeyFrames>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="BorderElement" Storyboard.TargetProperty="BorderBrush">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlBorderBrushDisabled}" />
                                            </ObjectAnimationUsingKeyFrames>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentElement" Storyboard.TargetProperty="Foreground">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlForegroundDisabled}" />
                                            </ObjectAnimationUsingKeyFrames>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="PlaceholderTextContentPresenter" Storyboard.TargetProperty="Foreground">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlPlaceholderForegroundDisabled}" />
                                            </ObjectAnimationUsingKeyFrames>
                                        </Storyboard>
                                    </VisualState>
                                    <VisualState x:Name="Normal" />

                                    <VisualState x:Name="PointerOver">

                                        <Storyboard>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="BorderElement" Storyboard.TargetProperty="BorderBrush">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlBorderBrushPointerOver}" />
                                            </ObjectAnimationUsingKeyFrames>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="BorderElement" Storyboard.TargetProperty="Background">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlBackgroundPointerOver}" />
                                            </ObjectAnimationUsingKeyFrames>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="PlaceholderTextContentPresenter" Storyboard.TargetProperty="Foreground">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlPlaceholderForegroundPointerOver}" />
                                            </ObjectAnimationUsingKeyFrames>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentElement" Storyboard.TargetProperty="Foreground">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlForegroundPointerOver}" />
                                            </ObjectAnimationUsingKeyFrames>
                                        </Storyboard>
                                    </VisualState>
                                    <VisualState x:Name="Focused">

                                        <Storyboard>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="PlaceholderTextContentPresenter" Storyboard.TargetProperty="Foreground">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlPlaceholderForegroundFocused}" />
                                            </ObjectAnimationUsingKeyFrames>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="BorderElement" Storyboard.TargetProperty="Background">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlBackgroundFocused}" />
                                            </ObjectAnimationUsingKeyFrames>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="BorderElement" Storyboard.TargetProperty="BorderBrush">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlBorderBrushFocused}" />
                                            </ObjectAnimationUsingKeyFrames>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentElement" Storyboard.TargetProperty="Foreground">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlForegroundFocused}" />
                                            </ObjectAnimationUsingKeyFrames>
                                            <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentElement" Storyboard.TargetProperty="RequestedTheme">
                                                <DiscreteObjectKeyFrame KeyTime="0" Value="Light" />
                                            </ObjectAnimationUsingKeyFrames>
                                        </Storyboard>
                                    </VisualState>
                                </VisualStateGroup>

                            </VisualStateManager.VisualStateGroups>
                            <Grid.RowDefinitions>
                                <RowDefinition Height="Auto" />
                                <RowDefinition Height="*" />
                            </Grid.RowDefinitions>
                            <Border x:Name="BorderElement"
                            Grid.Row="1"
                            Background="{TemplateBinding Background}"
                            BorderBrush="{TemplateBinding BorderBrush}"
                            BorderThickness="{TemplateBinding BorderThickness}"
                            Grid.ColumnSpan="2"
                            Grid.RowSpan="1" />
                            <ContentPresenter x:Name="HeaderContentPresenter"
                            x:DeferLoadStrategy="Lazy"
                            Visibility="Collapsed"
                            Grid.Row="0"
                            Foreground="{ThemeResource TextControlHeaderForeground}"
                            Margin="0,0,0,8"
                            Grid.ColumnSpan="2"
                            Content="{TemplateBinding Header}"
                            ContentTemplate="{TemplateBinding HeaderTemplate}"
                            FontWeight="Normal" />
                            <ScrollViewer x:Name="ContentElement"
                            Grid.Row="1"
                            HorizontalScrollMode="{TemplateBinding ScrollViewer.HorizontalScrollMode}"
                            HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}"
                            VerticalScrollMode="{TemplateBinding ScrollViewer.VerticalScrollMode}"
                            VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}"
                            IsHorizontalRailEnabled="{TemplateBinding ScrollViewer.IsHorizontalRailEnabled}"
                            IsVerticalRailEnabled="{TemplateBinding ScrollViewer.IsVerticalRailEnabled}"
                            IsDeferredScrollingEnabled="{TemplateBinding ScrollViewer.IsDeferredScrollingEnabled}"
                            Margin="{TemplateBinding BorderThickness}"
                            Padding="{TemplateBinding Padding}"
                            IsTabStop="False"
                            ZoomMode="Disabled"
                            AutomationProperties.AccessibilityView="Raw" />
                            <TextBlock x:Name="PlaceholderTextContentPresenter"
                            Grid.Row="1"
                            Foreground="{ThemeResource TextControlPlaceholderForeground}"
                            Margin="{TemplateBinding BorderThickness}"
                            Padding="{TemplateBinding Padding}"
                            Grid.ColumnSpan="2"
                            Text="{TemplateBinding PlaceholderText}"
                            TextAlignment="{TemplateBinding TextAlignment}"
                            IsHitTestVisible="False" />

                        </Grid>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>

从以上样式，您可以看到Disabled VisualState代码：

<VisualState x:Name="Disabled">

    <Storyboard>
        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="HeaderContentPresenter" Storyboard.TargetProperty="Foreground">
            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlHeaderForegroundDisabled}" />
        </ObjectAnimationUsingKeyFrames>
        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="BorderElement" Storyboard.TargetProperty="Background">
            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlBackgroundDisabled}" />
        </ObjectAnimationUsingKeyFrames>
        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="BorderElement" Storyboard.TargetProperty="BorderBrush">
            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlBorderBrushDisabled}" />
        </ObjectAnimationUsingKeyFrames>
        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentElement" Storyboard.TargetProperty="Foreground">
            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlForegroundDisabled}" />
        </ObjectAnimationUsingKeyFrames>
        <ObjectAnimationUsingKeyFrames Storyboard.TargetName="PlaceholderTextContentPresenter" Storyboard.TargetProperty="Foreground">
            <DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextControlPlaceholderForegroundDisabled}" />
        </ObjectAnimationUsingKeyFrames>
    </Storyboard>
</VisualState>

在此Disabled VisualState中，您发现禁用RichEditBox时ContentElement的{{1}}将是Foreground。由于在禁用RichEditBox时更改了文本的ThemeResource TextControlForegroundDisabled，因此会丢失颜色格式。

您可以通过删除将Foreground的{{1}}更改为以下 Disabled VisualState的代码来保持颜色格式：

ContentElement

Answer 2

Color myColor = Colors.Black; // this will act as your toggle of color you change it according to logic of your app in this case I will show you how you can retain the color even when disabled. Whenever you change the color of your richEditBox to red or to any color, just assign that color to it as well. Here I have set it default color to black.

private void OnDisable(object sender, RoutedEventArgs e)
{
    RichEditor.IsEnabled = false;
}

private void OnEnable(object sender, RoutedEventArgs e)
{
    RichEditor.IsEnabled = true;
    //Now after enabling just set the myColor property to RichEditBox Foreground.
    RichEditor.Document.Selection.CharacterFormat.ForegroundColor = myColor;
}

private void OnRed(object sender, RoutedEventArgs e)
{
     RichEditor.Document.Selection.CharacterFormat.ForegroundColor = Colors.Red;
     myColor = Colors.Red; // whatever color you set to the RichEditBox, set it to myColor as well.
}

RichEditBox在禁用然后启用时会失去颜色格式

2 个答案: