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

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 app）。 但问题是代码永远不会进入io.on（'connection'，…）。 i、 e.未建立插座连接

感谢您的帮助

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
        };

    }
}

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');
});

这是服务器端代码：

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
        };

    }
}

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');
});

---

安装npm模块

socket.io客户端

，然后重试

  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");
    });
  }
}

---

哦，我刚刚发现了问题。它适用于IOS，但不适用于Android。你能帮我一下吗？更换你的本地主机ip然后检查。。在我的Android和iOS设备中，将本地主机更改为ip有效！非常感谢。虽然我无法理解为什么会发生这种事@嗨，你能看看我的问题吗。