Question

WebSocket发送方法即使在onconnect之后尝试也会引发异常。并非总是如此，但很多时候我在控制台中看到了记录的异常。

这是打字稿代码： -

  open() {
    if ('WebSocket' in window) {
      this.ws = new WebSocket(ApiUrls.Socket(''));
      this.ws.onopen = () => {
        const authentication = {
          msgType : 'Authenticate',
          data : {
            token : localStorage.getItem('authToken')
          }
        }
        this.ws.send(JSON.stringify(authentication));
      };

      this.ws.onmessage = (evt) => {
        // console.log(evt);
        this.parseMessage(evt.data);
      };

      this.ws.onclose = () => {
        this.connected = false;
        // console.log('retrying connection with server');
        if (localStorage.getItem('authToken')) {
          this.reconnectTimeout = setTimeout(this.open.bind(this), 1000);
        }
      };
    } else {
      alert('WebSocket NOT supported by your Browser!');
    }
  }

控制台中的异常： -

ERROR DOMException: Failed to execute 'send' on 'WebSocket': Still in CONNECTING state.
    at WebSocket.ws.onopen [as __zone_symbol__ON_PROPERTYopen] (http://localhost:4200/main.bundle.js:5586:26)
    at WebSocket.wrapFn (http://localhost:4200/polyfills.bundle.js:3711:39)
    at ZoneDelegate.webpackJsonp.../../../../zone.js/dist/zone.js.ZoneDelegate.invokeTask (http://localhost:4200/polyfills.bundle.js:2970:31)
    at Object.onInvokeTask (http://localhost:4200/vendor.bundle.js:87677:33)
    at ZoneDelegate.webpackJsonp.../../../../zone.js/dist/zone.js.ZoneDelegate.invokeTask (http://localhost:4200/polyfills.bundle.js:2969:36)
    at Zone.webpackJsonp.../../../../zone.js/dist/zone.js.Zone.runTask (http://localhost:4200/polyfills.bundle.js:2737:47)
    at ZoneTask.webpackJsonp.../../../../zone.js/dist/zone.js.ZoneTask.invokeTask [as invoke] (http://localhost:4200/polyfills.bundle.js:3044:34)
    at invokeTask (http://localhost:4200/polyfills.bundle.js:4085:14)
    at WebSocket.globalZoneAwareCallback (http://localhost:4200/polyfills.bundle.js:4111:17)

它太冗长，但有关的信息是ERROR DOMException: Failed to execute 'send' on 'WebSocket': Still in CONNECTING state. at WebSocket.ws.onopen [as __zone_symbol__ON_PROPERTYopen]。

Answer 1

当open方法被调用两次时，这会中断。在这种情况下，ws属性将被仍处于连接状态的新Websocket覆盖。然后在onopen处理程序中使用错误的WebSocket（它是异步的）。

{{1}}

Answer 2

我发现这似乎有帮助：

gs://domain.com...

区别在于您使用触发onopen事件的websocket实例，而不是this.ws.onopen = (e) => { // Not sure if the following line is necessary but doesn't hurt if (e.target.readyState !== WebSocket.OPEN) return; const authentication = { msgType : 'Authenticate', data : { token : localStorage.getItem('authToken') } } // Here's the key: use the websocket instance that triggered the onopen event e.target.send(JSON.stringify(authentication)); }变量中存在的实例，因为this.ws同时可能发生了变化。

即使在触发onopen事件后，WebSocket仍处于CONNECTING状态

2 个答案: