WPF RichTextBox没有设置宽度

Question

我有以下XAML代码:

<Window x:Class="RichText_Wrapping.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window1">
<Grid>
    <RichTextBox Height="100" Margin="2" Name="richTextBox1">
        <FlowDocument>
            <Paragraph>
                This is a RichTextBox - if you don't specify a width, the text appears in a single column
            </Paragraph>
        </FlowDocument>
    </RichTextBox>
</Grid>

...如果在XAML中创建此窗口,您可以看到,当您没有为窗口指定宽度时,它会将文本包装在一个列中,一次一个字母.有什么我想念的吗？如果它是控制中已知的缺陷,是否有任何解决方法？

Answer 1

这是WPF RichTextBox的确认错误.要修复它,请将FlowDocument的PageWidth绑定到RichTextBox宽度,即

<RichTextBox Name="rtb">
    <FlowDocument Name="rtbFlowDoc" PageWidth="{Binding ElementName=rtb, Path=ActualWidth}" />
</RichTextBox>

编辑:为FlowDocument命名,以便您可以在后面的代码中访问它,并且永远不会在代码隐藏中新建流文档.

Answer 2

尝试将FlowDocument的宽度(单向)绑定到容器RichTextBox的宽度.

为我工作......

Answer 3

本文中的方法对我有用:

WPF RichTextBox不提供将其宽度调整为文本的功能.据我所知,RichTextBox在其可视树中使用FlowDocumentView来呈现Flowdocument.它将占用可用空间来呈现其内容,因此不会根据内容调整其大小.由于这是一个内部类,我们似乎无法覆盖布局过程,让RichTextBox将其大小调整为文本.

因此,我认为您的方法是正确的方向.不幸的是,根据我的研究,没有直接的方法来测量RichTextBox中渲染文本的大小.

我们可以尝试一种解决方法.我们可以递归遍历RichTextBox中的flowdocument来检索所有Run和Paragraph对象.然后我们将它们转换为FormattedText以获得大小.

本文演示如何将FlowDocument转换为FormattedText.我还在该文章中使用FlowDocumentExtensions类编写了一个简单的示例.

    public Window2()
    {
      InitializeComponent();

      StackPanel layoutRoot = new StackPanel();
      RichTextBox myRichTextBox = new RichTextBox() { Width=20};

      this.Content = layoutRoot;
      layoutRoot.Children.Add(myRichTextBox);

      myRichTextBox.Focus();
      myRichTextBox.TextChanged += new TextChangedEventHandler((o,e)=>myRichTextBox.Width=myRichTextBox.Document.GetFormattedText().WidthIncludingTrailingWhitespace+20);
    }


  public static class FlowDocumentExtensions
  {
    private static IEnumerable<TextElement> GetRunsAndParagraphs(FlowDocument doc)
    {
      for (TextPointer position = doc.ContentStart;
        position != null && position.CompareTo(doc.ContentEnd) <= 0;
        position = position.GetNextContextPosition(LogicalDirection.Forward))
      {
        if (position.GetPointerContext(LogicalDirection.Forward) == TextPointerContext.ElementEnd)
        {
          Run run = position.Parent as Run;

          if (run != null)
          {
            yield return run;
          }
          else
          {
            Paragraph para = position.Parent as Paragraph;

            if (para != null)
            {
              yield return para;
            }
          }
        }
      }
    }

    public static FormattedText GetFormattedText(this FlowDocument doc)
    {
      if (doc == null)
      {
        throw new ArgumentNullException("doc");
      }

      FormattedText output = new FormattedText(
        GetText(doc),
        CultureInfo.CurrentCulture,
        doc.FlowDirection,
        new Typeface(doc.FontFamily, doc.FontStyle, doc.FontWeight, doc.FontStretch),
        doc.FontSize,
        doc.Foreground);

      int offset = 0;

      foreach (TextElement el in GetRunsAndParagraphs(doc))
      {
        Run run = el as Run;

        if (run != null)
        {
          int count = run.Text.Length;

          output.SetFontFamily(run.FontFamily, offset, count);
          output.SetFontStyle(run.FontStyle, offset, count);
          output.SetFontWeight(run.FontWeight, offset, count);
          output.SetFontSize(run.FontSize, offset, count);
          output.SetForegroundBrush(run.Foreground, offset, count);
          output.SetFontStretch(run.FontStretch, offset, count);
          output.SetTextDecorations(run.TextDecorations, offset, count);

          offset += count;
        }
        else
        {
          offset += Environment.NewLine.Length;
        }
      }

      return output;
    }

    private static string GetText(FlowDocument doc)
    {
      StringBuilder sb = new StringBuilder();

      foreach (TextElement el in GetRunsAndParagraphs(doc))
      {
        Run run = el as Run;
        sb.Append(run == null ? Environment.NewLine : run.Text);
      }
      return sb.ToString();
    }
  }