我们可以在 WPF 的 RichTextBox 中以编程方式搜索突出显示的文本吗

Question

如下文末尾所示，使用Microsoft WORD VBA，我们可以搜索MS WORD文档中的所有高亮文本。在遗留 MS Office VSTO add-in 中使用 C# 也可以实现同样的效果。问题：我们如何以编程方式获取 WPF RichTextBox 中所有 highlighted 文本的 TexRanges？

WPF RichTextBox 显示:

获取rtf的代码:

string sRTF = "";
TextRange tr = new TextRange(rtbTest.Document.ContentStart, rtbTest.Document.ContentEnd);

using (MemoryStream ms = new MemoryStream())
{
    tr.Save(ms, DataFormats.Rtf);
    sRTF = ASCIIEncoding.Default.GetString(ms.ToArray());
}

Debug.Write(sRTF);

RTF 输出:

在下面的输出中，我们可以看到突出显示的文本 test 的 rtf 是 {\lang9\highlight2\ltrch test}。我们如何以编程方式在此处获取突出显示的文本（即 test）。这只是一个示例。，我的意思是以编程方式获取所有突出显示的文本？

{\rtf1\ansi\ansicpg1252\uc1\htmautsp\deff2{\fonttbl{\f0\fcharset0 Times New Roman;}{\f2\fcharset0 Calibri;}}{\colortbl\red0\green0\blue0;\red255\green255\blue255;\red255\green255\blue0;}\loch\hich\dbch\pard\plain\ltrpar\itap0{\lang1033\fs18\f2\cf0 \cf0\ql{\fs22\f2 {\lang9\ltrch This is a }{\lang9\highlight2\ltrch test}{\lang9\ltrch  for a WPF RichTextBox}\li0\ri0\sa200\sb0\fi0\ql\par}
{\f2 {\ltrch }\li0\ri0\sa0\sb0\fi0\ql\par}
}
}

我们能否像我们（例如）在 WORD 文档中通过如下所示的 VBA 宏或通过遗留 VSTO 加载项中的 c# 以编程方式在 WPF RichTextBox 中实现相同的功能：

Selection.Find.ClearFormatting
Selection.Find.Highlight = True
With Selection.Find
    .Text = ""
    .Replacement.Text = ""
    .Forward = True
    .Wrap = wdFindContinue
    .Format = True
    .MatchCase = False
    .MatchWholeWord = False
    .MatchWildcards = False
    .MatchSoundsLike = False
    .MatchAllWordForms = False
End With
Selection.Find.Execute
Selection.Find.Execute

Answer 1

要理解什么是算法可以用来分析FlowDocument的内容最好的方法是阅读Flexible Content Display With Flow Documentspost或者，例如阅读“文档”一章”在书中 MacDonald M. - Pro WPF 4.5 in C#。 Windows Presentation Foundation in .NET 4.5（.NET 专家之声），2012.

因此，FlowDocument 包含 BlockCollection Blocks 属性。这是整个 FlowDocument 内容的顶级块。

下面的代码使用此属性递归解析和分析 FlowDocument 中的所有元素，包括搜索具有指定背景颜色的文本片段。

出于测试目的，应用程序 window 包含 Color ComboBox 允许选择一些颜色并使用 设置颜色按钮。 搜索彩色文本 按钮开始扫描文档，找到带有指定颜色的文本并使用创建的 TextRange 列表将文本重绘为粉红色。

MainWindow.xaml

<Window ...
        Title="MainWindow" Height="350" Width="500" >
    <Grid>

        <Grid.RowDefinitions>
            <RowDefinition Height="*"/>
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>


        <RichTextBox Name="rtb" BorderBrush="LightGreen" 
                     Padding="5" Margin="10" VerticalScrollBarVisibility="Auto">
            <FlowDocument>
                <Paragraph>
                    <Run>?</Run> 
                </Paragraph>
            </FlowDocument>            
        </RichTextBox>
        <Grid Grid.Row="1" Margin="5">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="auto"/>
                <ColumnDefinition Width="auto" MinWidth="60"/>
                <ColumnDefinition Width="Auto"/>
                <ColumnDefinition Width="*"/>
            </Grid.ColumnDefinitions>

            <Grid.RowDefinitions>
                <RowDefinition Height="Auto"/>
                <RowDefinition Height="Auto"/>
                <RowDefinition Height="Auto"/>
            </Grid.RowDefinitions>

            <Label Content="Color: " />
            <ComboBox x:Name="ComboColor" Grid.Column="1" Width="150" Margin="3" SelectedValuePath="Name" >
                <ComboBox.ItemTemplate>
                    <DataTemplate>
                        <StackPanel Orientation="Horizontal">
                            <Rectangle Fill="{Binding Name}" Width="16" Height="16" Margin="0,0,5,0" />
                            <TextBlock Text="{Binding Name}" />
                        </StackPanel>
                    </DataTemplate>
                </ComboBox.ItemTemplate>
            </ComboBox>

            <Button Content="Set color" Grid.Row="1" Grid.Column="1" Padding="3" Margin="3" Click="SetColor_Click"/>
            <Button Content="Search colored text" Grid.Row="2" Grid.Column="1" Padding="3" Margin="3" Click="Search_Click"/>
        </Grid>

    </Grid>
</Window>

MainWindow.xaml.cs

using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Media;

namespace WpfApp17
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            ComboColor.ItemsSource = typeof(Colors).GetProperties();
            ComboColor.SelectedValue = "Brown";
        }

        private void Search_Click(object sender, RoutedEventArgs e)
        {
            Parsing(rtb);
        }

        public void Parsing(RichTextBox rtb)
        {
            // Get selected color 
            var c = System.Drawing.Color.FromName(ComboColor.SelectedValue.ToString());
          
            var parser = new RtfDocumentParser();

            // Initialization with selected color
            parser.Init(Color.FromArgb(c.A, c.R, c.G, c.B));

            // Processing 
            parser.Analyze(rtb);

            // Color found TextRanges to pink
            foreach (var tr in parser.TextRanges)
            {
                tr.ApplyPropertyValue(TextElement.BackgroundProperty, new SolidColorBrush(Colors.Pink));
            }
        }

        private void SetColor_Click(object sender, RoutedEventArgs e)
        {
            var selection = rtb.Selection;
            if (!selection.IsEmpty)
            {
                var c = System.Drawing.Color.FromName(ComboColor.SelectedValue.ToString());
                selection.ApplyPropertyValue(TextElement.BackgroundProperty, new SolidColorBrush(Color.FromArgb(c.A, c.R, c.G, c.B)));
            }
        }
    }
}

RtfDocumentParser.cs

using System;
using System.Collections.Generic;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Media;

namespace WpfApp17
{
    public class RtfDocumentParser
    {
        #region Public properties

        public Color SearchColor { get; private set; }
        public IList<TextRange> TextRanges { get; private set; }
        #endregion

        #region Private properties

        private TextPointer Start { get; set; }
        private TextPointer End { get; set; }
        #endregion

        #region ctor
        public RtfDocumentParser()
        {
            Init(Colors.Yellow);
        }
        #endregion

        #region Public methods
        public void Init(Color color)
        {
            SearchColor = color;
            TextRanges = new List<TextRange>();
        }

        public void Analyze(RichTextBox rtb)
        {
            ParseBlockCollection(rtb.Document.Blocks);
            CloseRange();
        }
        #endregion

        #region Private methods 

        private void ParseBlockCollection(BlockCollection blocks)
        {
            foreach (var block in blocks)
            {
                CloseRange();

                if (block is Paragraph para) { ParseInlineCollection(para.Inlines); }
                else if (block is List list)
                {
                    foreach (var litem in list.ListItems)
                    {
                        CloseRange();
                        TextRange range = new TextRange(litem.ElementStart, litem.ElementEnd);
                        ParseBlockCollection(litem.Blocks);
                    }
                }
                else if (block is Table table)
                {
                    foreach (TableRowGroup rowGroup in table.RowGroups)
                    {
                        foreach (TableRow row in rowGroup.Rows)
                        {
                            foreach (var cell in row.Cells)
                            {
                                ParseBlockCollection(cell.Blocks);
                            }
                        }
                    }
                }
                else if (block is BlockUIContainer blockui) { /* blockui.Child */ }
                else if (block is Section section) { ParseBlockCollection(section.Blocks); }
                else { throw new NotImplementedException(); }
            }
        }

        public void ParseInlineCollection(InlineCollection inlines)
        {
            foreach (var inline in inlines)
            {
                if (inline is Run r)
                {
                    Analyze(r);
                }
                else if (inline is InlineUIContainer || inline is LineBreak lbreak)
                {
                    CloseRange();
                }
                else if (inline is Span span)
                {
                    ParseInlineCollection(span.Inlines);
                }
            }
        }

        private void Analyze(Run run)
        {
            if (run.Background is SolidColorBrush rBrush)
            {
                CheckPositions(rBrush.Color, run.ElementStart, run.ElementEnd);
            }
            else if (run.Parent is Span span && span.Background is SolidColorBrush sBrush)
            {
                CheckPositions(sBrush.Color, run.ElementStart, run.ElementEnd);
            }
            else if (End != null)
            {
                CloseRange();
            }
        }

        private void CheckPositions(Color color, TextPointer start, TextPointer end)
        {
            if (color == SearchColor)
            {
                if (Start == null)
                {
                    Start = start;
                }
                else if (!IsMatch(start, End))
                {
                    TextRanges.Add(new TextRange(Start, End));
                    Start = start;
                }
                End = end;
            }
            else if (End != null)
            {
                CloseRange();
            }
        }
     
        private bool IsMatch(TextPointer start, TextPointer position)
        {
            for (; position != null; position = position.GetNextContextPosition(LogicalDirection.Forward))
            {
                //var context = position.GetPointerContext(LogicalDirection.Forward);
                if (start.CompareTo(position) == 0)
                    return true; // Match
            }
            return false;
        }

        private void CloseRange()
        {
            if (End is TextPointer) 
            {
                TextRanges.Add(new TextRange(Start, End));
            }
            Start = End = null;
        }

        #endregion
    }
}

我们可以在 WPF 的 RichTextBox 中以编程方式搜索突出显示的文本吗

Can we programmatically search highlighted text in RichTextBox of WPF

c#

wpf

richtextbox

rtf