关于生成静态分页，内容区用来Replace的问题

          下面黄色部份有问题，在生成静态html页成的时候内容不能循环替换。可我在调试的时候是能读取绿部分已经分组的内容的。不知道什么原因
            
       
            string filename = "/infoSkin.aspx?NewsID=" + Util.Encode(strNewsID.ToString());
            string serverport = Request.ServerVariables["SERVER_PORT"].ToString();
            string PageUrl = "";
            string ipath = Server.MapPath("/Html/" + mnews.Addtime.ToString("yyMMdd") + "/");
            if (Directory.Exists(ipath) == false)
            {
                Directory.CreateDirectory(ipath);
            }
            if (serverport == "80")
            {
                PageUrl = "http://" + Request.Url.Host + "/" + filename;
            }
            else
            {
                PageUrl = "http://" + Request.Url.Host + ":" + Request.ServerVariables["SERVER_PORT"] + "/" + filename;
            }
            WebRequest request = WebRequest.Create(PageUrl);
            WebResponse response = request.GetResponse();
            Stream resStream = response.GetResponseStream();
            StreamReader sr = new StreamReader(resStream, System.Text.Encoding.GetEncoding("utf-8"));
            string InfoHtml = sr.ReadToEnd();
            InfoHtml = InfoHtml.Replace("$title$", mnews.Title);
            resStream.Close();
            sr.Close();
            string[] strPage = mnews.Content.Split('|');
            string fileName = "";
            StreamWriter sw = null;
            StringBuilder sb = new StringBuilder("");
            for (int i = 0; i < strPage.Length; i++)
            {
                string aa = strPage[i];
                string dd = aa;                InfoHtml = InfoHtml.Replace("$content$",strPage[i]);
                sb.Append(i.ToString());
                //  InfoHtml = InfoHtml.Replace("$page$", sb.ToString());
                fileName = mnews.Addtime.ToString("yyyyMMddhhmmss_" + i) + ".html";
                sw = new StreamWriter(ipath + fileName, false, System.Text.Encoding.GetEncoding("gb2312"));
                sw.Write(InfoHtml);
            }
            sw.Flush();
            sw.Close();