asp.net过滤HTML字符

public string NoHTML(string Htmlstring) //去除HTML标记
  { 
   //删除脚本
   Htmlstring = Regex.Replace(Htmlstring,@"<script[^>]*?>.*?</script>","",RegexOptions.IgnoreCase);
   //删除HTML
   Htmlstring = Regex.Replace(Htmlstring,@"<(.[^>]*)>","",RegexOptions.IgnoreCase);
   Htmlstring = Regex.Replace(Htmlstring,@"([/r/n])[/s]+","",RegexOptions.IgnoreCase);
   Htmlstring = Regex.Replace(Htmlstring,@"-->","",RegexOptions.IgnoreCase);
   Htmlstring = Regex.Replace(Htmlstring,@"<!--.*","",RegexOptions.IgnoreCase);
   
   Htmlstring = Regex.Replace(Htmlstring,@"&(quot|#34);","/"",RegexOptions.IgnoreCase);
   Htmlstring = Regex.Replace(Htmlstring,@"&(amp|#38);","&",RegexOptions.IgnoreCase);
   Htmlstring = Regex.Replace(Htmlstring,@"&(lt|#60);","<",RegexOptions.IgnoreCase);
   Htmlstring = Regex.Replace(Htmlstring,@"&(gt|#62);",">",RegexOptions.IgnoreCase);
   Htmlstring = Regex.Replace(Htmlstring,@"&(nbsp|#160);"," ",RegexOptions.IgnoreCase);
   Htmlstring = Regex.Replace(Htmlstring,@"&(iexcl|#161);","/xa1",RegexOptions.IgnoreCase);
   Htmlstring = Regex.Replace(Htmlstring,@"&(cent|#162);","/xa2",RegexOptions.IgnoreCase);
   Htmlstring = Regex.Replace(Htmlstring,@"&(pound|#163);","/xa3",RegexOptions.IgnoreCase);
   Htmlstring = Regex.Replace(Htmlstring,@"&(copy|#169);","/xa9",RegexOptions.IgnoreCase);
   Htmlstring = Regex.Replace(Htmlstring, @"&#(/d+);","",RegexOptions.IgnoreCase);

   Htmlstring.Replace("<","");
   Htmlstring.Replace(">","");
   Htmlstring.Replace("/r/n","");
   Htmlstring=HttpContext.Current.Server.HtmlEncode(Htmlstring).Trim();

   return Htmlstring;
  }