<script>         if (typeof (EventSource) !== "undefined") {             //推送服務(wù)接口地址             var eventSource = new EventSource("http://localhost:2242/webservice/ServerSent/SentNews");             //當通往服務(wù)器的連接被打開             eventSource.onopen = function () {                 console.log("連接打開...");             }              //當錯誤發(fā)生              eventSource.onerror= function (e) {                  console.log(e);              };              //當接收到消息，此事件為默認事件              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對象                  var origin = event.origin;//服務(wù)器 URL 的域名部分，即協(xié)議、域名和端口，表示消息的來源。                  var lastEventId = event.lastEventId;////數(shù)據(jù)的編號，由服務(wù)器端發(fā)送。如果沒有編號，這個屬性為空。                  //此處根據(jù)需求編寫業(yè)務(wù)邏輯                  console.log(data);              }, false);          } else {              //瀏覽器不支持server-sent events 所有主流瀏覽器均支持服務(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>        /// 推送消息        /// </summary>        /// <returns></returns>        [HttpGet]        public HttpResponseMessage SentNews()        {            HttpResponseMessage response = Request.CreateResponse(HttpStatusCode.OK);            try            {                //response.Headers.Add("Access-Control-Allow-Origin", "*");//如需要跨域可配置                string data_str = “推送至客戶端的數(shù)據(jù)”;//當然可以是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";//連接斷開后重連時間（毫秒），其實可以理解為輪詢時間 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");//此處一定要配置                response.Headers.CacheControl = new CacheControlHeaderValue();                response.Headers.CacheControl.NoCache = false;            }            catch (Exception ex)            {                LogHelper.WriteWebLog(ex);            }            return response;        }