去除HTML标记

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Text.RegularExpressions;


/// <summary>
/// FiterHtml 的摘要说明
/// </summary>
public class FiterHtml
{
    public FiterHtml() { }
    ///   <summary>
    ///   去除HTML标记
    ///   </summary>
    public static string NoHTML( string Htmlstring)
    {
        //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;
    }
    public static string StripHTML( string strHtml)
    {
        string [] aryReg =
            {
              @"<script[^>]*?>.*?</script>" ,
              @"<(\/\s*)?!?((\w+:)?\w+)(\w+(\s*=?\s*(([""'])(\\[" ,
               @"'tbnr]|[^\7])*?\7|\w+)|.{0})|\s)*?(\/\s*)?>" , @"([\r\n])[\s]+" ,
                @"&(quot|#34);" , @"&(amp|#38);" , @"&(lt|#60);" , @"&(gt|#62);" ,
                @"&(nbsp|#160);" , @"&(iexcl|#161);" , @"&(cent|#162);" , @"&(pound|#163);" ,
                @"&(copy|#169);" , @"&#(\d+);" , @"-->" , @"<!--.*\n"
            };

        string [] aryRep =
            {
              "" , "" , "" , "\"" , "&" , "<" , ">" , "   " , "\xa1" ,  //chr(161),
              "\xa2" ,  //chr(162),
              "\xa3" ,  //chr(163),
              "\xa9" ,  //chr(169),
              "" , "\r\n" , ""
            };

        string newReg = aryReg [ 0 ];
        string strOutput = strHtml;
        for ( int i = 0; i < aryReg . Length; i ++)
        {
            Regex regex = new Regex( aryReg [ i ], RegexOptions . IgnoreCase);
            strOutput = regex . Replace( strOutput , aryRep [ i ]);
        }
        strOutput . Replace( "<" , "");
        strOutput . Replace( ">" , "");
        strOutput . Replace( "\r\n" , "");
        return strOutput;
    }
    ///   <summary>
    ///   移除HTML标签
    ///   </summary>
    ///   <param   name="HTMLStr">HTMLStr</param>
    public static string ParseTags( string HTMLStr)
    {
        return System . Text . RegularExpressions . Regex . Replace( HTMLStr , "<[^>]*>" , "");
    }
    ///   <summary>
    ///   取出文本中的图片地址
    ///   </summary>
    ///   <param   name="HTMLStr">HTMLStr</param>
    public static string GetImgUrl( string HTMLStr)
    {
        string str = string . Empty;
        string sPattern = @"^<img\s+[^>]*>";
        Regex r = new Regex( @"<img\s+[^>]*\s*src\s*=\s*([']?)(?<url>\S+)'?[^>]*>" ,
          RegexOptions . Compiled);
        Match m = r . Match( HTMLStr . ToLower());
        if ( m . Success)
            str = m . Result( "${url}");
        return str;
    }

}