RichEditBox 在禁用然后启用时丢失颜色格式

Question

我在 UWP 应用程序中使用 RichEditBox，我需要在软件中启用和禁用它以执行某些任务。我运行遇到的问题是，当我禁用然后重新启用它时，任何颜色格式都会丢失。我在这里创建了一个简单的例子来尝试这个问题。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;
}

这看起来像是 RichEditBox 组件中的错误，我想知道是否有人有解决方法允许我在不丢失颜色格式的情况下启用和禁用文本。下面的例子重现了这个问题。

Answer 1

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.
}

Answer 2

参见 Control style and template part in the RichEditBox Class:

You can modify the default Style and ControlTemplate to give the control a unique appearance.The default style, template, and resources that define the look of the control are included in the generic.xaml file. For design purposes, generic.xaml is available in the (Program Files)\Windows Kits\DesignTime\CommonConfiguration\Neutral\UAP<SDK version>\Generic folder from a Windows Software Development Kit (SDK) installation. Styles and resources from different versions of the SDK might have different values.

所以你可以找到System.Windows.Controls.RichEditBox控件的默认样式，这里是1803版本的默认样式目标：

<!-- 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>

从上面的样式中，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>

在这个DisabledVisualState中，你可以发现当你禁用[=37=时ContentElement的Foreground将是ThemeResource TextControlForegroundDisabled ]RichEditBox。由于在禁用 RichEditBox 时文本的 Foreground 已更改，因此您将丢失颜色格式。

您可以通过删除更改 ContentElement 的 Foreground 的代码来保留颜色格式，如下所示 Disabled VisualState:

<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>

RichEditBox 在禁用然后启用时丢失颜色格式

RichEditBox looses color formatting when disable then enable

uwp

isenabled

richeditbox