public static string noTagHtml(string str, string tagname)

        {

            string zz = @"(<" + tagname + ".*?>)|(</" + tagname + ">)";

            if (tagname == "script") zz = "(<" + tagname + ".*?>)*(</" + tagname + ">)";

            //过滤除P标签的所有标签，不清除P标签里css样式

            else if (tagname == "p")

            {

                //zz = @"</?\s*(?!p|br)+\b[^>]*>";

                zz = @"</?\s*(?!br)+\b[^>]*>";

                Regex r = new Regex(zz, RegexOptions.IgnoreCase | RegexOptions.Singleline);

                str = Regex.Replace(str, zz, "", RegexOptions.IgnoreCase);

                str = r.Replace(str, "");

            }

            else if (tagname == "*")

            {

                zz = @"(<([^>]*)>)";

                Regex r = new Regex(zz, RegexOptions.IgnoreCase | RegexOptions.Singleline);

                str = Regex.Replace(str, zz, "", RegexOptions.IgnoreCase);

                str = r.Replace(str, "");

                Regex regex1 = new Regex(@"\n", RegexOptions.IgnoreCase);

                str = regex1.Replace(str, "");

                Regex regex2 = new Regex(@"\n[\s| ]*\r", RegexOptions.IgnoreCase);

                str = regex2.Replace(str, "");

                string[] hangCounts = str.Split('\r');

                string strTempList = "";

                for (int k = ; k < hangCounts.Length; k++)

                {

                    if (!strTempList.Equals(""))

                    {

                        strTempList = strTempList + "";

                    }

                    if (!hangCounts[k].Equals(""))

                    {

                        strTempList = strTempList + "<p>" + hangCounts[k] + "</p>\r\n";

                    }

                }

                strTempList = strTempList + "";

                str = strTempList;

            }

            else

            {

                Regex r = new Regex(zz, RegexOptions.IgnoreCase | RegexOptions.Singleline);

                str = Regex.Replace(str, zz, "", RegexOptions.IgnoreCase);

                str = r.Replace(str, "");

            }

            return (str);

        }