private static Regex HrefAttribute = new Regex("href=\".*?\"", RegexOptions.IgnoreCase);
html = HrefAttribute.Replace(html, string.Empty
2、正则替换字符---------------------------------------------------------------------------------------------------------------------------
string strxmlstr = tw.ToString();
Regex HrefAttribute = new Regex("<jiesuancontract>([^<]*)</jiesuancontract>|<yusuanprice>([^<]*)</yusuanprice>|<chushengprice>([^<]*)</chushengprice>|<shengdingprice>([^<]*)</shengdingprice>", RegexOptions.IgnoreCase);
string html = HrefAttribute.Replace(strxmlstr, string.Empty).Trim();
3、正则提取字符----------------------------------------------------------------------------------------------------------------------------
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=gb2312">
<title>哈哈哈哈</title>
</head>
<body style="margin:0px"><center>你好世界！</center>"><center>你好世界！</center></body></html>
设textBox1.text="为你的文本";
string regexStr = @"<center>([^<]*)</center>";
Match mc = Regex.Match(textBox1.Text.Replace("\n", ""), regexStr, RegexOptions.IgnoreCase);
MessageBox.Show("结果为:" + mc.Groups[1].Value);