javascript - 套接字不适用于使用 ws 的 React native 和 Node.js 服务器

Question

我正在尝试使用套接字将我的后端(node.js 服务器)连接到前端( react native 应用程序)。但问题是代码永远不会进入 io.on('connection', ...)。即没有建立套接字连接。

感谢任何帮助。

这是客户端代码:

import React, { Component } from 'react';
import {
    Alert,
    Button,
    Text,
    View
} from 'react-native';    


export default class App extends Component {

    constructor(props) {
        super(props);
        const ws = new WebSocket('ws://localhost:3000');
        console.log("This is client side Web socket.")
        ws.onopen = () => {
            console.log("Its connected")
            ws.send('something'); // send a message
        };

    }
}

这是服务器端代码:

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

io.on('connection', function(socket){
      console.log('a user connected');
});

http.listen(3000, function(){
      console.log('listening on *:3000');
});

Answer 1

安装 npm 模块 socket.io-client 然后尝试

  import React, {
  Component
} from 'react';
import {
  Alert,
  Button,
  Text,
  View
} from 'react-native';
import SocketIOClient from 'socket.io-client';



export default class App extends Component {

  constructor(props) {
    super(props);
    var ws = SocketIOClient('ws://localhost:3000'); // replace localhost with ip
    ws.on('connect', function() {
      console.log("hello");
    });
  }
}