作者: blood 
  比较长，不过支持全部的关键字，直接就可以用了。
using System;
using System.Text;
using System.Text.RegularExpressions;

namespace Com.OSLeague.Component
{
/// <summary>
/// 语法分析器，将所有Code根据语法进行变色
/// <list type="VB">支持VB.NET</list>
/// <list type="CS">支持CS</list>
/// <author>掉掉</author>
/// <date>2002年5月14日</date>
/// <Memo>
/// 练习正则表达式
/// </Memo>
/// </summary>
public class CodeAnalysis
{

//
//定义HTML开始和结束的语句，用于语法变色
//

const string TAG_FNTRED = @"<font color=""red"">";
const string TAG_FNTBLUE = @"<font color=""blue"">" ;
const string TAG_FNTGRN = @"<font color=""green"">" ;
const string TAG_FNTMRN = @"<font color=""maroon"">" ;
const string TAG_FNTBLACK = @"<font color=""black"">" ;
const string TAG_EFONT = @"</font>" ;
const string TAG_SPNYELLOW = @"<span style=""background-color: yellow;"">";
const string TAG_ESPAN = @"</span>";
const string TAG_B = @"<b>";
const string TAG_EB = @"</b>";
const string TAG_COMMENT = @"<font colr=#008200>";
const string TAG_ECOMMENT = @"</font>";

//



public CodeAnalysis()
{
//
// TODO: 在此处添加构造函数逻辑
//
}



/// <summary>
/// 处理VB.NET代码，彩色化..
/// </summary>
/// <param name="Code">传入的Code</param>
/// <returns>处理过后的代码</returns>
public string ParseVB(string Code)
{
//
//定义VB.NET中关键字，将其存为数组
//

string[] VB_Keyword = new string[]
{
"AddHandler","AddressOf","AndAlso","Alias","And","Ansi","As","Assembly","Auto","Boolean",
"ByRef","Byte","ByVal","Call","Case","Catch","CBool","CByte","CChar",
"CDate","CDec","CDbl","Char","CInt","Class","CLng","CObj","Const",
"CShort","CSng","CStr","CType","Date","Decimal","Declare","Default",
"Delegate","Dim","DirectCast","Do","Double","Each","Else","ElseIf","End",
"Enum","Erase","Error","Event","Exit","False",
"Finally","For","Friend","Function","Get","GetType","GoTo","Handles","If",
"Implements","Imports","In","Inherits","Integer","Interface",
"Is","Let","Lib","Like","Long","Loop","Me","Mod","Module",
"MustInherit","MustOverride","MyBase","MyClass","Namespace","New","Next","Not","Nothing",
"NotInheritable","NotOverridable","Object","On","Option","Optional","Or","OrElse",
"Overloads","Overridable","Overrides","ParamArray","Preserve","Private","Property","Protected","Public",
"RaiseEvent","ReadOnly","ReDim","RemoveHandler","Resume","Return",
"Select","Set","Shadows","Shared","Short","Single","Static","Step","Stop",
"String","Structure","Sub","SyncLock","Then","Throw",
"To","True","Try","TypeOf","Unicode","Until","Variant","When","While",
"With","WithEvents","WriteOnly","Xor"
};



//
//设定转换代码颜色
//

string ReplaceVBComment = TAG_COMMENT + "$1" + TAG_ECOMMENT;
string ReplaceVBKeyword = TAG_FNTBLUE + "${char}" + TAG_EFONT;
//开始转换
for (int i=0;i<VB_Keyword.Length;i++)
{
string TempDirectives = @"(?<char>(\s" + VB_Keyword[i] + "|" + VB_Keyword[i] + @"\s))";
Code = Regex.Replace(Code,TempDirectives,ReplaceVBKeyword,RegexOptions.IgnoreCase);
Code = Regex.Replace(Code,@"'(?<x>[^\r\n]*)",ReplaceVBComment);
Code = Regex.Replace(Code,@"REM (?<x>[^\r\n]*)",ReplaceVBComment);
}
return Code; 
}
}
}