string d = "http://search.anccnet.com/searchResult2.aspx";        //name="__VIEWSTATE"  value="http://www.mamicode.com/wEPDwULLTEzODQxNzY5NjNkZEc4gDy0wp5ERjILg2b7lTTH3F+w"        //name="__EVENTVALIDATION"    value="http://www.mamicode.com/wEWAwKK7u6vCQLd5eLQCQLmjL2EBxmZU7jWYoh9371phOcBPCjfgdVD"         //name="keyword"         //name="gdsBtn"         Encoding myEncoding = Encoding.GetEncoding("gb2312");        string param = "__VIEWSTATE=" + HttpUtility.UrlEncode("/wEPDwULLTEzODQxNzY5NjNkZEc4gDy0wp5ERjILg2b7lTTH3F+w", myEncoding)            + "&" + "__EVENTVALIDATION=" + HttpUtility.UrlEncode("/wEWAwKK7u6vCQLd5eLQCQLmjL2EBxmZU7jWYoh9371phOcBPCjfgdVD", myEncoding)            + "&" + "keyword=" + HttpUtility.UrlEncode("6935706000259", myEncoding)            + "&" + "gdsBtn=" + HttpUtility.UrlEncode("111", myEncoding);        byte[] postBytes = Encoding.ASCII.GetBytes(param);        HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(d);        req.Method = "POST";        req.ContentType = "application/x-www-form-urlencoded;charset=gb2312";        req.ContentLength = postBytes.Length;        using (Stream reqStream = req.GetRequestStream())        {            reqStream.Write(postBytes, 0, postBytes.Length);        }        string html = "";        using (WebResponse wr = req.GetResponse())        {            Stream stream = wr.GetResponseStream();            StreamReader sr = new StreamReader(stream,System.Text.Encoding.GetEncoding("gb2312"));             html = sr.ReadToEnd();            //在这里对接收到的页面内容进行处理                    }        Response.Write(html);