asp.net 截取带有html标签的字符串(先过滤html,再截取)的方法

    /// <summary>    /// 根据汉字长度截取字符串    /// </summary>    /// <param name="value"></param>    /// <param name="length">中文字符串长度</param>    /// <returns></returns>    public static string CutString(this string value, int length)    {        if (string.IsNullOrEmpty(value)) return "";        int dataLength = length * 2;  //要截取的字节长度        byte[] bLength = Encoding.GetEncoding("gb2312").GetBytes(value);  //原字符串的字节长度        if (bLength.Length <= dataLength)            return value;        string strEndRes = "";        while (true)        {            strEndRes += value.Substring(strEndRes.Length, length);            int size = dataLength - Encoding.GetEncoding("gb2312").GetBytes(strEndRes).Length;            if (size <= 1)            {                if (size == 1 && Encoding.GetEncoding("gb2312").GetBytes(value.Substring(strEndRes.Length, 1)).Length == 1)                {                    strEndRes += value.Substring(strEndRes.Length, 1);                }                return strEndRes;            }            length = size / 2;        }    }        #region 回车,空格过滤    /**/    /// <summary>      /// 去除HTML标记      /// </summary>      /// <param name="NoHTML">包括HTML的源码 </param>      /// <returns>已经去除后的文字</returns>      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;    }    #endregion

 asp.net 截取带有html标签的字符串(先过滤html,再截取)的方法用到这个的一般是显示文章内容的摘要的时候.
一般文章内容里有html的时候,用一般的截取,会将内容里的html一起给截出来,轻则显示出不必要的乱码,重则导致网站样式/布局的破坏.
要解决这个问题很容易,两步就可以搞定
一,过滤掉内容里的html.
二,截取过滤后的内容.
这里把c#的代码放出来.