vs 通过地址获取平台的返回信息

  public static string RequstJson(string username, string password)
        {
            string rtn;
            string response;
          
            Encoding e = Encoding.GetEncoding("GBK");
           
            string param = "http://地址/iccty/essyu/session.do?" + HttpUtility.UrlEncode("userId", e) + "=" + HttpUtility.UrlEncode(username, e)
            + "&" + HttpUtility.UrlEncode("password", e) + "=" + HttpUtility.UrlEncode(password, e);

            HttpWebRequest req = (HttpWebRequest)WebRequest.Create(param);
            req.Method = "GET";

            HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
            Stream stream = resp.GetResponseStream();
            //获取响应内容
            using (StreamReader reader = new StreamReader(stream, e))
            {
                response = reader.ReadToEnd();
            }
            if (response.Contains("对不起，该用户不存在"))
            {
                rtn = "NO";
            }
            else
            {
                rtn = "YES";
            }

 

            return rtn;
        }

    }