使用 HttpWebRequest的psot方式传参数调用接口方法

 public ContentResult UseHttpWebRquust(string url,string param)
        {
            HttpWebResponse response = null;
            Stream stream = null;
            StreamReader streamReader = null;
            Stream responseStream = null;
            string jsontext = string.Empty;
                try
                {
                    HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
                    request.Method = "POST";
                    request.Accept = "*/*";
                    request.ContentType = "multipart/byteranges";//根据需要设置请求内容类型
                    request.Timeout = 50000;
                    request.KeepAlive = true;//建立永久链接
                    request.ProtocolVersion = HttpVersion.Version10;
                    //request.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 2.0.50727;)";
                    //ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;
                   

                    byte[] data = Encoding.Default.GetBytes(param);
                    request.ContentLength = data.Length;

                    using (stream = request.GetRequestStream())
                    {
                        stream.Write(data, 0, data.Length);

                    }
                    response = request.GetResponse() as HttpWebResponse;
                    responseStream = response.GetResponseStream();
                    streamReader = new StreamReader(responseStream, Encoding.UTF8);
                    SmsResult smsResult = Newtonsoft.Json.JsonConvert.DeserializeObject<SmsResult>(jsontext);
                    result = smsResult.resultCode;
                    if (responseStream != null)
                    {
                        responseStream.Close();
                    }
                    if (streamReader != null)
                    {
                        streamReader.Close();
                    }
                    if (stream != null)
                    {
                        stream.Close();
                    }
                    //关闭stream的顺序要正确
                }
                catch (System.Exception ex)
                {
                    return Content(result.ToString());
                }
                return Content(result.ToString());
           
        }