模拟Form提交，得到结果页内容

        /// <summary>        /// 根据任务要素构造抓取的url        /// </summary>        protected override string createUrl(int pageIndex)        {            NameValueCollection PostVars = new NameValueCollection();            PostVars.Add("mod", "forum");            PostVars.Add("srchtype", "title");            PostVars.Add("srhfid", "0");            PostVars.Add("srhlocality", "portal::index");            PostVars.Add("srchtxt", keyWord);            string sRemoteInfo = CommonFunction.getSearchResault(PostVars, "http://bbs.tuniu.com/search.php?searchsubmit=yes", true);            Regex regexRtCt = new Regex(@"<div class=""pgs cl mbm""><div class=""pg"">[\s\S]+?</div></div>");            MatchCollection matchRtCtList = regexRtCt.Matches(sRemoteInfo);            Regex regexRtCtHref = new Regex(@"<a[\s\S]+?>[\s\S]+?</a>");            Regex regexRtCtURL = new Regex(@"href=""[\s\S]+?"">");            string strUrlTemp = "http://bbs.tuniu.com/" + regexRtCtURL.Match(regexRtCtHref.Matches(matchRtCtList[0].Value)[0].Value).Value.Replace("href=\"", "").Replace("\">", "").Replace("page=2", "page=");            string strUrl = strUrlTemp + pageIndex;                        return strUrl;        }

        /// <summary>        /// 模拟Form提交，得到结果页内容        /// </summary>        public static string getSearchResault(NameValueCollection PostVars, string searchUrl, bool UrlEncodeUtf8)        {            WebClient WebClientObj = new WebClient();            string sRemoteInfo = "";            try            {                byte[] byRemoteInfo = WebClientObj.UploadValues(searchUrl, "POST", PostVars);                if (UrlEncodeUtf8)                {                    sRemoteInfo = System.Text.Encoding.UTF8.GetString(byRemoteInfo);                }                else                {                    sRemoteInfo = System.Text.Encoding.Default.GetString(byRemoteInfo);                }            }            catch            {            }            return sRemoteInfo;        }