淺談HTML5 服務(wù)器推送事件Server-sent Events

     <script>
         if (typeof (EventSource) !== "undefined") {
             //推送服務(wù)接口地址
             var eventSource = new EventSource("http://localhost:2242/webservice/ServerSent/SentNews");
             //當(dāng)通往服務(wù)器的連接被打開
             eventSource.onopen = function () {
                 console.log("連接打開...");
             }
              //當(dāng)錯(cuò)誤發(fā)生
              eventSource.onerror= function (e) {
                  console.log(e);
              };
              //當(dāng)接收到新聞，此事件為默認(rèn)事件
              eventSource.onmessage = function (event) {
                  console.log("onmessage...");
          　　　　 eventSource.close()//關(guān)閉SSE鏈接
              };
              //服務(wù)器推送sentMessage事件
              eventSource.addEventListener('sentMessage', function (event) { 
                  var data = eval('('+event.data+')');//服務(wù)器端推送的數(shù)據(jù)，eval裝換Json對(duì)象
                  var origin = event.origin;//服務(wù)器 URL 的域名部分，即協(xié)議、域名和端口，透露表現(xiàn)新聞的來源。
                  var lastEventId = event.lastEventId;////數(shù)據(jù)的編號(hào)，由服務(wù)器端發(fā)送。假如沒有編號(hào)，這個(gè)屬性為空。
                  //此處根據(jù)需求編寫營(yíng)業(yè)邏輯
                  console.log(data);              }, false);
          } else {
              //欣賞器不支持server-sent events 所有主流欣賞器均支持服務(wù)器發(fā)送事件，除了 Internet Explorer。
              document.getElementById("result").innerHTML = "Sorry, your browser does not support server-sent events...";
          }
      </script>

　　　　/// <summary>
        /// 推送新聞
        /// </summary>
        /// <returns></returns>
        [HttpGet]
        public HttpResponseMessage SentNews()
        {
            HttpResponseMessage response = Request.CreateResponse(HttpStatusCode.OK);
            try
            {
                //response.Headers.Add("Access-Control-Allow-Origin", "*");//如必要跨域可配置
                string data_str = “推送至客戶端的數(shù)據(jù)”;//當(dāng)然可以是json字符串格式
                string even = "", data = "";
                if (!string.IsNullOrWhiteSpace(data_str))
                {
                    even = "event:sentMessage\n";
                    data = "data:" + data_str + "\n\n";
                }
                string retry = "retry:" + 1000 + "\n";//連接斷開后重連時(shí)間（毫秒），其實(shí)可以理解為輪詢時(shí)間 2333...
                byte[] array = Encoding.UTF8.GetBytes(even + data + retry);
                Stream stream_result = new MemoryStream(array);
                response.Content = new StreamContent(stream_result);
                response.Content.Headers.ContentType = new MediaTypeHeaderValue("text/event-stream");//此處肯定要配置
                response.Headers.CacheControl = new CacheControlHeaderValue();
                response.Headers.CacheControl.NoCache = false;
            }
            catch (Exception ex)
            {
                LogHelper.WriteWebLog(ex);
            }
            return response;
        }