Socket.io服务器和客户端之间没有通信

Question

var app = require('express')();
var http = require('http');
var server = http.createServer(app);
var io = require('socket.io').listen(server);

io.on('connection', function() {
    io.emit('update');
    console.log('Connected');
});
io.on('updated', function() {
    io.emit('update');
    console.log('Updated');
});

server.listen(5000, function() {
    console.log('Listening on 5000');
});

import { Component } from '@angular/core';

import * as io from 'socket.io-client';

@Component({
  selector: 'main-app',
  template: `
  <div>
  <button (click)="foo()"
           style='padding:20px; background:red; color:white'>
    click me
  </button>
  </div>
  `
})
export class AppComponent {
  title = 'bar';
  socket = null;

  constructor() {
    let self = this;
      self.socket = io.connect('http://mysuperwebsite:5000', {
          transports : ["websocket"]
      });
      self.socket.on('update', function(data) {
        console.log(data);
      });
  }

  foo() {
    let self = this;
    self.socket.emit('updated', {});
  }
}

编辑：最后，问题似乎来自io.emit（）中缺少第二个参数。现在它起作用了，非常感谢：）

Answer 1

我将发布一个有效的示例，而不是调试您的代码，您可以从那里开始：

使用Express.js的Socket.io服务器示例：

var path = require('path');
var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);
app.get('/', (req, res) => {
  console.error('express connection');
  res.sendFile(path.join(__dirname, 'si.html'));
});
io.on('connection', s => {
  console.error('socket.io connection');
  for (var t = 0; t < 3; t++)
    setTimeout(() => s.emit('message', 'message from server'), 1000*t);
});
http.listen(3002, () => console.error('listening on http://localhost:3002/'));
console.error('socket.io example');

来源：https://github.com/rsp/node-websocket-vs-socket.io/blob/master/si.js

var l = document.getElementById('l');
var log = function (m) {
    var i = document.createElement('li');
    i.innerText = new Date().toISOString()+' '+m;
    l.appendChild(i);
}
log('opening socket.io connection');
var s = io();
s.on('connect_error', function (m) { log("error"); });
s.on('connect', function (m) { log("socket.io connection open"); });
s.on('message', function (m) { log(m); });

它是为这个答案而写的--你可以在那里找到更多的信息。