正则表达式辅助类

using System;
using System.IO;
using System.Text ;
using System.Collections;
using System.Collections.Specialized;
using System.Text.RegularExpressions;

namespace LF.Framework
{
///
/// ------------------------------------------------
/// 创建时间:2005-11-07
/// 正则表达式辅助类
/// 已经通过单元测试
///
public class RegAssist
{
///
/// 查找文本(/w+)英文字母下划线
///
///
///
///
static private MatchCollection findText(string input,string pattern)
{
Regex reg = new Regex(pattern);
return reg.Matches(input);
}
///
/// 查找在标记中的文本(/w+)英文字母下划线
///
/// 输入字符串
/// 左标记
/// 右标记
/// 查找到的文本集合
static public StringCollection FindTextBetweenTag(string input,string leftTag,string rightTag)
{
leftTag = Regex.Escape(leftTag);
rightTag = Regex.Escape(rightTag);
string pattern = @"(?<={0})/w+(?={1})";
pattern = string.Format(pattern,leftTag,rightTag);

MatchCollection mc = RegAssist.findText(input,pattern);
StringCollection sc = new StringCollection();
foreach(Match m in mc)
{
sc.Add(m.Value);
}
return sc;
}
///
/// 替换标记中的文本(/w+)英文字母下划线
///
/// 输入字符串
/// 左标记
/// 右标记
/// 替换文本，如果需要包括原匹配字符串，请使用{0}
/// 替换后的字符串
static public string ReplaceBetweenTag(string input,string leftTag,string rightTag,string replacement)
{
leftTag = Regex.Escape(leftTag);
rightTag = Regex.Escape(rightTag);
string pattern = @"(?<={0})/w+(?={1})";
pattern = string.Format(pattern,leftTag,rightTag);

if(replacement.IndexOf("{0}")>=0)
{
MatchCollection mc = RegAssist.findText(input,pattern);
foreach(Match m in mc)
{
string ptn = pattern.Replace(@"/w+",m.Value);
string rep = string.Format(replacement,m.Value);
Regex reg = new Regex(ptn);
input = reg.Replace(input,rep);
}
}
else
{
input = Regex.Replace(input,pattern,replacement);
}
return input;
}
}
}