从 http 长寿命 Web 服务获取实时数据答案

【问题标题】：Get real-time data from a http long lived web service从 http 长寿命 Web 服务获取实时数据
【发布时间】：2012-07-18 03:57:19
【问题描述】：

我有一个长期存在的 http 网络服务。如果它有新数据，它将使用 http GET 推送到客户端。如何使用 HttpWebRequest c# 从 http 长寿命 Web 服务接收实时数据？

【问题讨论】：

标签： c# httpwebrequest

【解决方案1】：

如果你想使用Get获取数据，你可以使用这个（使用GetResponse时响应是同步的）：

 public string GetMessageViaGet(string endPoint)
        {
            HttpWebRequest request = CreateWebRequest(endPoint);

            using (var response = (HttpWebResponse)request.GetResponse())
            {
                var responseValue = string.Empty;

                if (response.StatusCode != HttpStatusCode.OK)
                {
                    string message = String.Format("Request failed. Received HTTP {0}", response.StatusCode);
                    throw new ApplicationException(message);
                }

                // grab the response  
                using (var responseStream = response.GetResponseStream())
                {
                    using (var reader = new StreamReader(responseStream))
                    {
                        responseValue = reader.ReadToEnd();
                    }
                }

                return responseValue;
            }
        }
        private HttpWebRequest CreateWebRequest(string endPoint)
        {
            var request = (HttpWebRequest)WebRequest.Create(endPoint);

            request.Method = "GET";
            request.ContentLength = 0;
            request.ContentType = "text/xml";
            return request;
        }

【讨论】：

【解决方案2】：

如果您想通过 post 获取数据，请执行此操作

   public string GetMessageViaPost(string endPoint, string paramtersJson)
        {
            string responseValue;
            byte[] bytes = Encoding.UTF8.GetBytes(paramtersJson);

            HttpWebRequest request = CreateWebRequest(endPoint, bytes.Length);

            using (var requestStream = request.GetRequestStream())
            {
                requestStream.Write(bytes, 0, bytes.Length);
            }

            using (var response = (HttpWebResponse)request.GetResponse())
            {
                if (response.StatusCode != HttpStatusCode.OK)
                {
                    string message = String.Format("POST failed. Received HTTP {0}", response.StatusCode);
                    throw new ApplicationException(message);
                }
                // grab the response  
                using (var responseStream = response.GetResponseStream())
                {
                    using (var reader = new StreamReader(responseStream))
                    {
                        responseValue = reader.ReadToEnd();
                    }
                }
            }

            return responseValue;
        }

        private HttpWebRequest CreateWebRequest(string endPoint, Int32 contentLength)
        {
            var request = (HttpWebRequest)WebRequest.Create(endPoint);

            request.Method = "POST";
            request.ContentLength = contentLength;
            request.ContentType = "application/json";// "application/x-www-form-urlencoded";

            return request;
        }

【讨论】：