<Window
    x:Class="WpfCSharpCodeEditor.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:local="clr-namespace:WpfCSharpCodeEditor"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    x:Name="mainWindow"
    Title="WPF簡單C#代碼編輯器"
    Width="1000"
    Height="700"
    ResizeMode="CanResize"
    WindowStartupLocation="CenterScreen"
    mc:Ignorable="d">
    <Grid Margin="5">
        <!--  定義全局樣式，統(tǒng)一界面風(fēng)格  -->
        <Grid.Resources>
            <!--  代碼編輯區(qū)域字體樣式  -->
            <Style x:Key="CodeTextStyle" TargetType="TextBlock">
                <Setter Property="FontFamily" Value="Consolas" />
                <Setter Property="FontSize" Value="14" />
                <Setter Property="Foreground" Value="#FFFFFF" />
            </Style>
            <!--  行號區(qū)域樣式  -->
            <Style x:Key="LineNumberStyle" TargetType="TextBlock">
                <Setter Property="FontFamily" Value="Consolas" />
                <Setter Property="FontSize" Value="14" />
                <Setter Property="Foreground" Value="#808080" />
                <Setter Property="TextAlignment" Value="Right" />
                <Setter Property="Padding" Value="0,0,5,0" />
            </Style>
        </Grid.Resources>

        <!--  核心布局：左右分欄（行號+代碼編輯）  -->
        <Grid.ColumnDefinitions>
            <!--  行號區(qū)域（固定寬度）  -->
            <ColumnDefinition Width="50" />
            <!--  代碼編輯區(qū)域（自適應(yīng)剩余寬度）  -->
            <ColumnDefinition Width="*" />
        </Grid.ColumnDefinitions>

        <!--  1. 行號區(qū)域（帶滾動，與編輯區(qū)域同步）  -->
        <ScrollViewer
            x:Name="ScrollLineNumber"
            Grid.Column="0"
            Background="#1E1E1E"
            HorizontalScrollBarVisibility="Hidden"
  
            VerticalScrollBarVisibility="Hidden">
            <TextBlock
                x:Name="TxtLineNumber"
                Margin="5,2,5,2"
                Style="{StaticResource LineNumberStyle}" />
        </ScrollViewer>

        <!--  2. 代碼編輯區(qū)域（核心：移除外層ScrollViewer，優(yōu)化RichTextBox屬性）  -->
        <RichTextBox
            x:Name="RtbCodeEditor"
            Grid.Column="1"
            Padding="5,2,5,2"
            AcceptsReturn="True"
            AcceptsTab="True"
            Background="#1E1E1E"
            BorderThickness="0"
            FontFamily="Consolas"
            FontSize="14"
            Foreground="#FFFFFF"
            HorizontalScrollBarVisibility="Auto"
            KeyDown="RtbCodeEditor_KeyDown"
            TextChanged="RtbCodeEditor_TextChanged"
            VerticalScrollBarVisibility="Auto">

            <FlowDocument
                ColumnWidth="999999"
                PagePadding="0"
                PageWidth="{Binding ElementName=MainWindow, Path=ActualWidth}"
                TextAlignment="Left">
                <Paragraph Margin="0" LineHeight="20" />

            </FlowDocument>
        </RichTextBox>
    </Grid>
</Window>

using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfCSharpCodeEditor;

using System;
using System.Collections.Generic;
using System.Text.RegularExpressions;
using System.Windows;
using System.Windows.Documents;
using System.Windows.Media;
using System.Windows.Input;


public partial class MainWindow : Window
{
    // 常量：C#核心關(guān)鍵字（可根據(jù)需求擴(kuò)展）
    private readonly HashSet<string> _csharpKeywords = new HashSet<string>
        {
            "using", "namespace", "class", "public", "private", "protected",
            "static", "void", "int", "string", "bool", "double", "float",
            "if", "else", "for", "foreach", "while", "do", "return",
            "new", "this", "base", "try", "catch", "finally"
        };

    // 常量：語法著色顏色
    private readonly SolidColorBrush _keywordBrush = new SolidColorBrush(Color.FromRgb(0, 122, 204)); // 藍(lán)色（關(guān)鍵字）
    private readonly SolidColorBrush _commentBrush = new SolidColorBrush(Color.FromRgb(0, 128, 0));   // 綠色（注釋）
    private readonly SolidColorBrush _stringBrush = new SolidColorBrush(Color.FromRgb(255, 165, 0));  // 橙色（字符串）
    private readonly SolidColorBrush _defaultBrush = new SolidColorBrush(Color.FromRgb(255, 255, 255));// 白色（默認(rèn)文本）

    // 輔助變量：標(biāo)記是否正在執(zhí)行語法高亮（避免TextChanged事件遞歸觸發(fā)）
    private bool _isHighlighting = false;

    public MainWindow()
    {
        InitializeComponent();
        // 初始化行號
        UpdateLineNumbers();
        // 初始化示例C#代碼
        InitSampleCode();
    }



    /// <summary>
    /// 初始化示例C#代碼
    /// </summary>
    private void InitSampleCode()
    {
        string sampleCode = @"using System;

namespace WpfCSharpCodeEditor
{
    // 簡單C#代碼示例
    public class SampleClass
    {
        public static void Main(string[] args)
        {
            // 輸出問候語
            string message = ""Hello, WPF C# Code Editor!"";
            Console.WriteLine(message);
            
            // 簡單循環(huán)
            for (int i = 0; i < 5; i++)
            {
                Console.WriteLine(""Loop index: "" + i);
            }
        }
    }
}";

        // 將示例代碼寫入RichTextBox
        RtbCodeEditor.Document.Blocks.Clear();
        Paragraph paragraph = new Paragraph();
        paragraph.Inlines.Add(new Run(sampleCode));
        RtbCodeEditor.Document.Blocks.Add(paragraph);

        // 執(zhí)行首次語法高亮
        HighlightCSharpSyntax();
        // 更新行號
        UpdateLineNumbers();
    }

    /// <summary>
    /// 代碼編輯區(qū)域滾動事件（同步行號區(qū)域滾動，適配RichTextBox內(nèi)置滾動）
    /// </summary>
    private void RtbCodeEditor_ScrollChanged(object sender, ScrollChangedEventArgs e)
    {
        if (e.VerticalChange != 0)
        {
            ScrollLineNumber.ScrollToVerticalOffset(e.VerticalOffset);
        }
    }

    /// <summary>
    /// 更新行號顯示
    /// </summary>
    private void UpdateLineNumbers()
    {
        // 獲取代碼總行數(shù)
        int lineCount = GetCodeLineCount();
        // 構(gòu)建行號文本
        StringBuilder lineNumberText = new StringBuilder();
        for (int i = 1; i <= lineCount; i++)
        {
            lineNumberText.AppendLine(i.ToString());
        }
        // 賦值給行號TextBlock
        TxtLineNumber.Text = lineNumberText.ToString();
    }

    /// <summary>
    /// 獲取代碼總行數(shù)
    /// </summary>
    /// <returns>總行數(shù)</returns>
    private int GetCodeLineCount()
    {
        // 從RichTextBox中提取文本并統(tǒng)計(jì)行數(shù)
        TextRange textRange = new TextRange(RtbCodeEditor.Document.ContentStart, RtbCodeEditor.Document.ContentEnd);
        string codeText = textRange.Text;
        if (string.IsNullOrEmpty(codeText)) return 1;
        // 統(tǒng)計(jì)換行符數(shù)量，總行數(shù)=換行符數(shù)+1
        return codeText.Split(new[] { Environment.NewLine }, StringSplitOptions.None).Length;
    }

    /// <summary>
    /// 代碼編輯區(qū)域滾動事件（同步行號區(qū)域滾動）
    /// </summary>
    private void ScrollCodeEditor_ScrollChanged(object sender, ScrollChangedEventArgs e)
    {
        if (e.VerticalChange != 0)
        {
            ScrollLineNumber.ScrollToVerticalOffset(e.VerticalOffset);
        }
    }




    /// <summary>
    /// C#語法高亮核心方法
    /// </summary>
    private void HighlightCSharpSyntax()
    {
        // 防止遞歸觸發(fā)（TextChanged事件中調(diào)用此方法，避免重復(fù)執(zhí)行）
        if (_isHighlighting) return;
        _isHighlighting = true;

        try
        {
            // 1. 保存當(dāng)前光標(biāo)位置與選區(qū)（避免高亮后光標(biāo)丟失）
            TextPointer caretPosition = RtbCodeEditor.CaretPosition;
            TextRange selectionRange = new TextRange(RtbCodeEditor.Selection.Start, RtbCodeEditor.Selection.End);
            bool hasSelection = !selectionRange.IsEmpty;

            // 2. 提取完整代碼文本
            TextRange fullTextRange = new TextRange(RtbCodeEditor.Document.ContentStart, RtbCodeEditor.Document.ContentEnd);
            string codeText = fullTextRange.Text;
            if (string.IsNullOrEmpty(codeText)) return;

            // 3. 清空現(xiàn)有格式（保留文本內(nèi)容）
            fullTextRange.ClearAllProperties();

            // 4. 分步實(shí)現(xiàn)語法著色
            // 4.1 匹配多行注釋 /* ... */
            MatchCollection multiLineCommentMatches = Regex.Matches(codeText, @"/\*.*?\*/", RegexOptions.Singleline);
            ApplyHighlightToMatches(multiLineCommentMatches, _commentBrush);

            // 4.2 匹配單行注釋 // ...
            MatchCollection singleLineCommentMatches = Regex.Matches(codeText, @"http://.*?$", RegexOptions.Multiline);
            ApplyHighlightToMatches(singleLineCommentMatches, _commentBrush);

            // 4.3 匹配字符串 ""...""
            MatchCollection stringMatches = Regex.Matches(codeText, @"\""([^\""\\]|\\.)*\""", RegexOptions.Multiline);
            ApplyHighlightToMatches(stringMatches, _stringBrush);

            // 4.4 匹配C#關(guān)鍵字（邊界匹配，避免匹配到單詞中的子串）
            string keywordPattern = @"\b(" + string.Join("|", _csharpKeywords) + @")\b";
            MatchCollection keywordMatches = Regex.Matches(codeText, keywordPattern, RegexOptions.IgnoreCase);
            ApplyHighlightToMatches(keywordMatches, _keywordBrush);

            // 5. 恢復(fù)光標(biāo)位置與選區(qū)
            RtbCodeEditor.CaretPosition = caretPosition;
            if (hasSelection)
            {
                RtbCodeEditor.Selection.Select(selectionRange.Start, selectionRange.End);
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show($"語法高亮失?。簕ex.Message}", "錯(cuò)誤提示", MessageBoxButton.OK, MessageBoxImage.Error);
        }
        finally
        {
            _isHighlighting = false;
        }
    }

    /// <summary>
    /// 為匹配到的語法元素應(yīng)用著色
    /// </summary>
    /// <param name="matches">正則匹配結(jié)果集合</param>
    /// <param name="brush">著色畫筆</param>
    private void ApplyHighlightToMatches(MatchCollection matches, SolidColorBrush brush)
    {
        foreach (Match match in matches)
        {
            if (match.Success && match.Length > 0)
            {
                // 獲取匹配項(xiàng)的起始與結(jié)束位置對應(yīng)的TextPointer
                TextPointer startPointer = GetTextPointerByOffset(match.Index);
                TextPointer endPointer = GetTextPointerByOffset(match.Index + match.Length);
                if (startPointer != null && endPointer != null)
                {
                    TextRange matchRange = new TextRange(startPointer, endPointer);
                    // 應(yīng)用前景色
                    matchRange.ApplyPropertyValue(TextElement.ForegroundProperty, brush);
                    // 可選：設(shè)置粗體（關(guān)鍵字加粗）
                    if (brush == _keywordBrush)
                    {
                        matchRange.ApplyPropertyValue(TextElement.FontWeightProperty, FontWeights.Bold);
                    }
                }
            }
        }
    }

    /// <summary>
    /// 根據(jù)字符偏移量獲取對應(yīng)的TextPointer
    /// </summary>
    /// <param name="offset">字符偏移量</param>
    /// <returns>對應(yīng)的TextPointer</returns>
    private TextPointer GetTextPointerByOffset(int offset)
    {
        TextPointer start = RtbCodeEditor.Document.ContentStart;
        int currentOffset = 0;
        while (start != null && currentOffset < offset)
        {
            if (start.GetPointerContext(LogicalDirection.Forward) == TextPointerContext.Text)
            {
                int textLength = start.GetTextRunLength(LogicalDirection.Forward);
                if (currentOffset + textLength > offset)
                {
                    return start.GetPositionAtOffset(offset - currentOffset);
                }
                currentOffset += textLength;
            }
            start = start.GetNextContextPosition(LogicalDirection.Forward);
        }
        return start;
    }


    /// <summary>
    /// 代碼文本變化事件（更新行號+語法高亮）
    /// </summary>
    private void RtbCodeEditor_TextChanged(object sender, System.Windows.Controls.TextChangedEventArgs e)
    {
        // 更新行號
        UpdateLineNumbers();
        // 執(zhí)行語法高亮
        HighlightCSharpSyntax();
    }

    /// <summary>
    /// 鍵盤按下事件（優(yōu)化編輯體驗(yàn)：Tab縮進(jìn)、回車自動縮進(jìn)）
    /// </summary>
    private void RtbCodeEditor_KeyDown(object sender, KeyEventArgs e)
    {
        // 1. Tab鍵：插入4個(gè)空格（代替默認(rèn)Tab字符，保持格式統(tǒng)一）
        if (e.Key == Key.Tab)
        {
            // 取消默認(rèn)Tab行為
            e.Handled = true;
            // 插入4個(gè)空格作為縮進(jìn)
            RtbCodeEditor.CaretPosition.InsertTextInRun("    ");
        }

        // 2. 回車鍵：自動縮進(jìn)（匹配上一行的縮進(jìn)格式）
        if (e.Key == Key.Enter)
        {
            // 取消默認(rèn)回車行為（后續(xù)手動處理）
            e.Handled = true;

            // 獲取當(dāng)前行的縮進(jìn)字符串
            string currentIndent = GetCurrentLineIndent();

            // 插入回車+縮進(jìn)
            RtbCodeEditor.CaretPosition.InsertTextInRun(Environment.NewLine + currentIndent);

            // 調(diào)整光標(biāo)位置（保持在縮進(jìn)后）
            RtbCodeEditor.CaretPosition = RtbCodeEditor.CaretPosition.GetPositionAtOffset(currentIndent.Length);
        }
    }

    /// <summary>
    /// 獲取當(dāng)前行的縮進(jìn)字符串（空格）
    /// </summary>
    /// <returns>縮進(jìn)字符串</returns>
    private string GetCurrentLineIndent()
    {
        TextPointer caret = RtbCodeEditor.CaretPosition;
        // 定位到當(dāng)前行的起始位置
        TextPointer lineStart = caret.GetLineStartPosition(0);
        if (lineStart == null) return string.Empty;

        // 提取當(dāng)前行從起始到光標(biāo)位置的文本
        TextRange lineRange = new TextRange(lineStart, caret);
        string lineText = lineRange.Text;

        // 提取前面的空格（縮進(jìn)部分）
        StringBuilder indentBuilder = new StringBuilder();
        foreach (char c in lineText)
        {
            if (c == ' ')
            {
                indentBuilder.Append(c);
            }
            else
            {
                break;
            }
        }

        return indentBuilder.ToString();
    }
}