TreeView 中 WPF RichTextBox 的拉伸宽度

Question

我的目标只是让 RichTextBox 占用 TreeView 内的整个行宽。下面的 XAML 将生成一个带有 RichTextBox 元素的 TreeView，但宽度只有 1 个字符宽。

我遇到过以下有关 RichTextBox 中宽度错误的帖子。这些问题可能已得到修复，因为独立的 RichTextBox 具有预期的宽度。尽管如此，我仍然尝试创建 Grids，将 Alignments 设置为 Stretch，并将 FlowDocument PageWidth 绑定到 parent，但没有成功。

[新] 我正在添加我的应用程序的描述，以防有人想提出 RTB 替代方案。我有一个包含 10-1000 个 RTB 节点的 TreeView。 TextBox 和 TextBlock 不实用，因为我需要完整的格式和用户编辑。

WPF RichTextBox with no width set

A WPF RichTextBox + Button in a StackPanel => what a mess?

<TreeView>
    <RichTextBox>
        <FlowDocument>
            <Paragraph>
                <Run>
                    Hello
                </Run>
            </Paragraph>
        </FlowDocument>
    </RichTextBox>
</TreeView>

谢谢，

Answer 1

正如你所说，这是known issue

提供的解决方法是：

<TreeView Name="RTBContainer" >
 <RichTextBox  Width="{Binding Path=ActualWidth, ElementName=RTBContainer, Mode=OneWay}">
       <FlowDocument >
         <Paragraph>
           <Run>
               Hello
          </Run>
        </Paragraph>
     </FlowDocument>
  </RichTextBox>
</TreeView>

Answer 2

您的问题源于 TreeViewItem 默认模板。 TreeViewItem 元素包装放置在 TreeView 中的任何内容。 TreeViewItem 的模板是包含三列的 Grid，前两列的宽度设置为 Auto，而第三列的宽度设置为 *。保存 Header 内容的元素位于第二列，其内容对齐方式设置为 Left。

我已经提取了 TreeViewItem 的模板并对其进行了修改，以便标题的内容容器跨越第二列和第三列，并将其内容对齐设置为拉伸。

（这是对 WPF 模板的修改克隆，所以有点冗长）

<TreeView>
    <TreeView.ItemContainerStyle>
        <Style TargetType="TreeViewItem">
            <!-- set the headers content to stretch -->
            <Setter Property="Control.HorizontalContentAlignment" Value="Stretch"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="TreeViewItem" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
                        <Grid>
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="Auto" MinWidth="19" />
                                <ColumnDefinition Width="Auto" />
                                <ColumnDefinition Width="*" />
                            </Grid.ColumnDefinitions>
                            <Grid.RowDefinitions>
                                <RowDefinition Height="Auto" />
                                <RowDefinition />
                            </Grid.RowDefinitions>
                            <ToggleButton IsChecked="False" ClickMode="Press" Name="Expander">
                                <ToggleButton.Style>
                                    <Style TargetType="ToggleButton">
                                        <Style.Resources>
                                            <ResourceDictionary />
                                        </Style.Resources>
                                        <Setter Property="UIElement.Focusable">
                                            <Setter.Value>
                                                <s:Boolean>False</s:Boolean>
                                            </Setter.Value>
                                        </Setter>
                                        <Setter Property="FrameworkElement.Width">
                                            <Setter.Value>
                                                <s:Double>16</s:Double>
                                            </Setter.Value>
                                        </Setter>
                                        <Setter Property="FrameworkElement.Height">
                                            <Setter.Value>
                                                <s:Double>16</s:Double>
                                            </Setter.Value>
                                        </Setter>
                                        <Setter Property="Control.Template">
                                            <Setter.Value>
                                                <ControlTemplate TargetType="ToggleButton">
                                                    <Border Padding="5,5,5,5" Background="#00FFFFFF" Width="16" Height="16">
                                                        <Path Fill="#00FFFFFF" Stroke="#FF989898" Name="ExpandPath">
                                                            <Path.Data>
                                                                <PathGeometry Figures="M0,0L0,6L6,0z" />
                                                            </Path.Data>
                                                            <Path.RenderTransform>
                                                                <RotateTransform Angle="135" CenterX="3" CenterY="3" />
                                                            </Path.RenderTransform>
                                                        </Path>
                                                    </Border>
                                                    <ControlTemplate.Triggers>
                                                        <Trigger Property="UIElement.IsMouseOver">
                                                            <Setter Property="Shape.Stroke" TargetName="ExpandPath">
                                                                <Setter.Value>
                                                                    <SolidColorBrush>#FF1BBBFA</SolidColorBrush>
                                                                </Setter.Value>
                                                            </Setter>
                                                            <Setter Property="Shape.Fill" TargetName="ExpandPath">
                                                                <Setter.Value>
                                                                    <SolidColorBrush>#00FFFFFF</SolidColorBrush>
                                                                </Setter.Value>
                                                            </Setter>
                                                            <Trigger.Value>
                                                                <s:Boolean>True</s:Boolean>
                                                            </Trigger.Value>
                                                        </Trigger>
                                                        <Trigger Property="ToggleButton.IsChecked">
                                                            <Setter Property="UIElement.RenderTransform" TargetName="ExpandPath">
                                                                <Setter.Value>
                                                                    <RotateTransform Angle="180" CenterX="3" CenterY="3" />
                                                                </Setter.Value>
                                                            </Setter>
                                                            <Setter Property="Shape.Fill" TargetName="ExpandPath">
                                                                <Setter.Value>
                                                                    <SolidColorBrush>#FF595959</SolidColorBrush>
                                                                </Setter.Value>
                                                            </Setter>
                                                            <Setter Property="Shape.Stroke" TargetName="ExpandPath">
                                                                <Setter.Value>
                                                                    <SolidColorBrush>#FF262626</SolidColorBrush>
                                                                </Setter.Value>
                                                            </Setter>
                                                            <Trigger.Value>
                                                                <s:Boolean>True</s:Boolean>
                                                            </Trigger.Value>
                                                        </Trigger>
                                                    </ControlTemplate.Triggers>
                                                </ControlTemplate>
                                            </Setter.Value>
                                        </Setter>
                                    </Style>
                                </ToggleButton.Style>
                            </ToggleButton>
                            <!-- other problem was here set the Borders ColumnSpan to 2 -->
                            <Border BorderThickness="{TemplateBinding Border.BorderThickness}" Padding="{TemplateBinding Control.Padding}" BorderBrush="{TemplateBinding Border.BorderBrush}" Background="{TemplateBinding Panel.Background}" Name="Bd" SnapsToDevicePixels="True" Grid.Column="1" HorizontalAlignment="Stretch" Grid.ColumnSpan="2" >
                                <ContentPresenter Content="{TemplateBinding HeaderedContentControl.Header}" ContentTemplate="{TemplateBinding HeaderedContentControl.HeaderTemplate}" ContentStringFormat="{TemplateBinding HeaderedItemsControl.HeaderStringFormat}" ContentSource="Header" Name="PART_Header" HorizontalAlignment="{TemplateBinding Control.HorizontalContentAlignment}" SnapsToDevicePixels="{TemplateBinding UIElement.SnapsToDevicePixels}" />
                            </Border>
                            <ItemsPresenter Name="ItemsHost" Grid.Column="1" Grid.Row="1" Grid.ColumnSpan="2" />
                        </Grid>
                        <ControlTemplate.Triggers>
                            <Trigger Property="TreeViewItem.IsExpanded">
                                <Setter Property="UIElement.Visibility" TargetName="ItemsHost">
                                    <Setter.Value>
                                        <x:Static Member="Visibility.Collapsed" />
                                    </Setter.Value>
                                </Setter>
                                <Trigger.Value>
                                    <s:Boolean>False</s:Boolean>
                                </Trigger.Value>
                            </Trigger>
                            <Trigger Property="ItemsControl.HasItems">
                                <Setter Property="UIElement.Visibility" TargetName="Expander">
                                    <Setter.Value>
                                        <x:Static Member="Visibility.Hidden" />
                                    </Setter.Value>
                                </Setter>
                                <Trigger.Value>
                                    <s:Boolean>False</s:Boolean>
                                </Trigger.Value>
                            </Trigger>
                            <Trigger Property="TreeViewItem.IsSelected">
                                <Setter Property="Panel.Background" TargetName="Bd">
                                    <Setter.Value>
                                        <DynamicResource ResourceKey="{x:Static SystemColors.HighlightBrushKey}" />
                                    </Setter.Value>
                                </Setter>
                                <Setter Property="TextElement.Foreground">
                                    <Setter.Value>
                                        <DynamicResource ResourceKey="{x:Static SystemColors.HighlightTextBrushKey}" />
                                    </Setter.Value>
                                </Setter>
                                <Trigger.Value>
                                    <s:Boolean>True</s:Boolean>
                                </Trigger.Value>
                            </Trigger>
                            <MultiTrigger>
                                <MultiTrigger.Conditions>
                                    <Condition Property="TreeViewItem.IsSelected">
                                        <Condition.Value>
                                            <s:Boolean>True</s:Boolean>
                                        </Condition.Value>
                                    </Condition>
                                    <Condition Property="Selector.IsSelectionActive">
                                        <Condition.Value>
                                            <s:Boolean>False</s:Boolean>
                                        </Condition.Value>
                                    </Condition>
                                </MultiTrigger.Conditions>
                                <Setter Property="Panel.Background" TargetName="Bd">
                                    <Setter.Value>
                                        <DynamicResource ResourceKey="{x:Static SystemColors.ControlBrushKey}" />
                                    </Setter.Value>
                                </Setter>
                                <Setter Property="TextElement.Foreground">
                                    <Setter.Value>
                                        <DynamicResource ResourceKey="{x:Static SystemColors.ControlTextBrushKey}" />
                                    </Setter.Value>
                                </Setter>
                            </MultiTrigger>
                            <Trigger Property="UIElement.IsEnabled">
                                <Setter Property="TextElement.Foreground">
                                    <Setter.Value>
                                        <DynamicResource ResourceKey="{x:Static SystemColors.GrayTextBrushKey}" />
                                    </Setter.Value>
                                </Setter>
                                <Trigger.Value>
                                    <s:Boolean>False</s:Boolean>
                                </Trigger.Value>
                            </Trigger>
                        </ControlTemplate.Triggers>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </TreeView.ItemContainerStyle>
    <RichTextBox HorizontalAlignment="Stretch" HorizontalContentAlignment="Stretch">
        <FlowDocument>
            <Paragraph>
                <Run>
                    Hello
                </Run>
            </Paragraph>
        </FlowDocument>
    </RichTextBox>
</TreeView>