Interactive C# Syntax Highlighter

This is a live online demo of our open-source C# Syntax Highlighter. We use, on the server-side, exactly the same classes presented in our project, that you can download and install on your computer. So please try to not abuse this online service and use it just sporadically.

Copy and paste here below your own C# code, press Submit button and get in return equivalent, but formatted, text. To see the actual HTML code generated for your text, find the first occurrence of a PRE tag in the HTML source code for the whole page. By default, the text box is filled in with the full source code of the CSharpSyntaxHighlighter class itself, which provides the main implementation of the C# syntax highlighter:

Your C# Code (maximum 5000 chars):

// Copyright (C) 2007 XtractPro (Data Extraction Magazine) // http://xtractpro.com, support@xtractpro.com // // This code is provided AS IS, with NO WARRANTY expressed or implied. // Any use of this free open source code is at your own risk. // // You are hereby granted the right to use it and change it, // provided that you acknowledge XtractPro somewhere in your // source files, documentation, web site and application. using System; using System.Diagnostics; using System.Text; using System.Web; using System.Collections; using System.Collections.Specialized; namespace XtractPro.Text { /// <summary> /// Syntax Highlighter for C# programming language /// </summary> public class CSharpSyntaxHighlighter : SyntaxHighlighter { // All keywords used by C# language syntax private static ArrayList _keywords = new ArrayList(); static CSharpSyntaxHighlighter() { string KEYWORDS = "abstract as base bool break byte " + "case catch char checked class const continue " + "decimal default delegate do double else enum event explicit extern " + "false finally fixed float for foreach " + "goto if implicit in int interface internal is " + "lock long namespace new null object operator out override " + "params private protected public readonly ref return " + "sbyte sealed short sizeof stackalloc static string struct switch " + "this throw true try typeof uint ulong unchecked unsafe ushort using " + "virtual void while #region #endregion"; _keywords.AddRange(KEYWORDS.Split(' ')); } /// <summary> /// Returns highlighted HTML from unformatted C# text code /// </summary> /// <param name="code">C# source code text</param> /// <returns>highlighted HTML</returns> protected override string ProcessThis(string code) { _buffer = code.Trim(' ', '\t', '\r', '\n'); _result = new StringBuilder(_buffer.Length * 2); _start = _chars = 0; // sequential traversal of input string buffer while (_start < _buffer.Length) { // collected an identifier? (keyword, directive, type, other) if (_chars > 0 && (Char.IsWhiteSpace(Current()) || Char.IsPunctuation(Current()) && Current() != '#')) AddIdentifier(); // character value? ('...') if (Current() == '\'') AddCharValue(); // string value? ("..." or verbatim @"...") else if (Current() == '"' || Current() == '@' && Current(1) == '"') AddStringValue(); // comment? (single-line, multi-line, documentation) else if (Current() == '/' && (Current(1) == '*' || Current(1) == '/')) { if (Current(1) == '*') AddMultiLineComment(); else if (Current(2) == '/') AddDocumentationComment(); else AddSingleLineComment(); } // advance/collect next whitespace/punctuation/identifier char else { if (Char.IsWhiteSpace(Current()) || Char.IsPunctuation(Current()) && Current() != '#') _result.Append(Encode(Current().ToString())); else _chars++; _start++; } } // collect last identifier if (_chars > 0) AddIdentifier(); // add line numbers, Show/Hide outer collapsible block and embed result AddLineNumbers(); return "<div class=\"sh_result\"><pre>" + AddCollapsibleBlock("") + _result.ToString() + EndCollapsibleBlock() + "</pre></div>"; } #region Parsing private methods /// <summary> /// Collect an identifier. /// Pre-condition: _chars>0 /// </summary> /// <returns>Formatted HTML for identifier</returns> private string AddIdentifier() { Debug.Assert(_chars > 0); string token = Substring(-_chars); _chars = 0; Debug.Assert(token.Length > 0); // keyword? if (_keywords.Contains(token)) { // directive? (#region or #endregion) if (token[0] == '#') { bool region = (token == "#region"); _end = FindNext(NewLine(), _start, 0); token = AddSpan(token, "net_directive") + AddHyperlinks(Substring()); token = (region ? AddCollapsibleBlock(token) : token + EndCollapsibleBlock()); _start = _end; } else token = AddSpan(token, "net_key"); } // type name? else if (_types.Contains(token)) token = AddSpan(token, "net_type"); // any other identifier is HTML-encoded else token = Encode(token); _result.Append(token); return token; } /// <summary> /// Collect a character value '...' /// Pre-condition: current char is ' /// </summary> /// <returns>Formatted HTML for char value</returns> private string AddCharValue() { Debug.Assert(Current() == '\''); _start++; for (_end = _start; CharAt(_end) != '\0' && (CharAt(_end) != '\'' || CharAt(_end - 1) == '\\' && CharAt(_end - 2) != '\\'); _end++) ; string token = Substring(); _result.Append(AddSpan("'" + Encode(token) + "'", "net_string")); _start = _end + 1; return token; } /// <summary> /// Collect a string value "..." or verbatim (multi-line) @"..." /// Pre-condition: starts by " or @" /// </summary> /// <returns>Formatted HTML for string value</returns> private string AddStringValue() { Debug.Assert(Current() == '"' || Current() == '@' && Current(1) == '"'); bool verbatim = (Current() == '@'); _start++; // @"..." verbatim string value continues till " // or odd number of consecutive " found if (verbatim) { _start++; bool evenQuotes = true; for (_end = _start; CharAt(_end) != '\0' && (CharAt(_end) != '\"' || (evenQuotes = !evenQuotes) || CharAt(_end + 1) == '\"'); _end++) ; } // "..." string value continue till " // not preceeded by single \ (\\" is actually \ followed by ") else for (_end = _start; CharAt(_end) != '\0' && (CharAt(_end) != '\"' || CharAt(_end - 1) == '\\' && CharAt(_end - 2) != '\\'); _end++) ; string token = Substring(); _result.Append(AddSpan((verbatim ? "@" : "") + "\"" + AddHyperlinks(token) + "\"", "net_string")); _start = _end + 1; return token; } /// <summary> /// Collect single-line comment // ... /// </summary> /// <returns>Formatted HTML for comment</returns> private string AddSingleLineComment() { _start += 2; // collects all text from // till end-of-line _end = FindNext(NewLine(), _start, 0); string token = Substring(); if (!_showComments) { // if skip comments, just replace everything with an empty line _result.Append(NewLine()); _end++; } else _result.Append(AddSpan("//" + AddHyperlinks(token), "net_comment")); _start = _end + 1; return token; } /// <summary> /// Collect multi-line comment /* ... */ /// </summary> /// <returns>Formatted HTML for comment</returns> private string AddMultiLineComment() { _start += 2; // collects all text from /* till next */ _end = FindNext("*/", _start, 2); string token = Substring(); if (_showComments) _result.Append(AddSpan("/*" + AddHyperlinks(token), "net_comment")); _start = _end + 1; return token; } /// <summary> /// Collect documentation (single-line) comment /// ... /// Detect and format <...> documentation tags inside /// </summary> /// <returns>Formatted HTML for comment</returns> private string AddDocumentationComment() { _start += 3; // collects all text from /// till end-of-line _end = FindNext(NewLine(), _start, 0); string token = Substring(); if (!_showComments) { // if skip comments, just replace everything with an empty line _result.Append(NewLine()); _end++; } else { // /// and <...> XML doc tags inside are shown in light gray _result.Append(AddSpan("///", "net_xml")); for (int end = _end; _start < end; _start++) { if (Current() == '<') { // show regular comment text _result.Append(AddSpan( AddHyperlinks(Substring(-_chars)), "net_comment")); _chars = 0; // show <...> XML tag content _end = FindNext(">", _start, 1); _result.Append(AddSpan( AddHyperlinks(Substring()), "net_xml")); _start = _end - 1; } else _chars++; _end = end; } // show last regular comment text left if (_chars > 0) { _result.Append(AddSpan( AddHyperlinks(Substring(-_chars)), "net_comment")); _chars = 0; } } _start = _end + 1; return token; } #endregion } }

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