1、建立service文件
ng g service share/web-socket --app
2、web.sockect.service.ts 文件如下

import {Injectable} from '@angular/core';
import * as io from 'socket.io-client';
import {Subject} from 'rxjs/Subject';
import {Observable} from 'rxjs/Observable';


@Injectable()
export class WebSocketService {
   private ws: any;
    private message: Subject<any> = new Subject<any>(); // 消息列表
    constructor() {

    }

    // 连接后台socket
    connetSocket(url) {
        this.ws = io(url);
        this.ws.on('connect_error', (error) => { // 连接失败
            console.log('connect_error');
        });
        this.ws.on('reconnecting', (timeout) => { // 重连次数
            if (timeout === 3) {
                this.ws.close();
            }
        });
        this.ws.on('message', (data) => {
            this.analysisMessage(data);
        });
    }

    analysisMessage(message) {
        //const messagejson = JSON.parse(message);
        this.message.next(message);
    }

    getMessage(): Observable<any> {
        return this.message.asObservable();
    }

}

3组件文件

import {Component, OnInit} from '@angular/core';
import {_HttpClient} from '@delon/theme';
import {WebSocketService} from '@shared/web-socket.service';
@Component({
    selector: 'app-messagelist',
    templateUrl: './messagelist.component.html',
    providers: [WebSocketService]
})
export class MessagelistComponent implements OnInit {
    public message = [];

    constructor(
        private http: _HttpClient,
        private messageService: WebSocketService
    ) {
    }

    ngOnInit() {
        this.connect();
    }

    connect() {
        this.messageService.connetSocket('http://localhost:8086/message');
    }

    getMessage() {
        this.messageService.getMessage().subscribe(result => {
            console.log(result);
        });
    }
}

4服务端文件

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

server.listen(8086); 
console.log('服务正常启动')
//警告：app.listen(80)在这里不起作用！

app.get('/',function(req,res) { 
  res.sendFile(__dirname + '/ index.html'); 
});
const messageServer=io.of('message')
messageServer.on('connection',function(socket) { 
   console.log('链接')
   const message=[{ 'value':'1111' },{'value':'2222'}] 
   setInterval(()=>{
      message.push({
         'value':'3333'
      })
      socket.emit('message',message)
   },1000)
      socket.on('my other event',function(data) {
            console.log(data) 
      }
    )
 })