如何使用websocket+node.js实现pc后台与小程序端实时通信-编程知识

如何使用websocket+node.js实现pc后台与小程序端实时通信

一、使用node.js创建一个服务器
二、pc后台连接ws
三、小程序端连接ws
四、实现效果

实现功能:实现pc后台与小程序端互发通信能够实时检测到

一、使用node.js创建一个服务器

1.安装ws依赖

npm i ws

2.创建index.js

const WebSocket = require('ws')const wss = new WebSocket.Server({ port: 8888 })
const wsList = {}
console.log('服务器启动')
wss.on('connection', (ws) => {ws.on('message', (message) => {const result = JSON.parse(message)console.log('接收到的结果', result)// 页面初始化的时候，使用wsList将ws进行缓存if (result.message === 'init') {wsList[result.name] = ws} else {// 根据name的值来给指定的客户端发送信息const ws = wsList[result.name]ws.send(result.message)}})ws.on('close', () => {Object.keys(wsList).forEach((item) => {// 当websoket关闭的时候，要清空对应的wsif (wsList[item].readyState !== 1) {delete wsList[item]}})})
})

3.打开终端,启动服务

node index.js

二、pc后台连接ws

<!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8" /><meta http-equiv="X-UA-Compatible" content="IE=edge" /><meta name="viewport" content="width=device-width, initial-scale=1.0" /><title>Document</title></head><body><span>P后台</span></div><input type="text" id="input" /><button id="button">发送</button><script>var ws = new WebSocket(`ws://localhost:8888`)//连接wsws.onopen = function () {ws.send(JSON.stringify({ name: 'PC', message: 'init' }))console.log('已连接')}//接收ws.onmessage = async function (mes) {console.log('pc接收到的消息', mes)}let Btn = document.getElementById('button')//发送事件Btn.onclick = function () {let ipt = document.querySelector('#input')let obj = {name: 'WX',message: ipt.value,}//需转成字符串ws.send(JSON.stringify(obj))}</script></body>
</html>

三、小程序端连接ws

这里是手动点击连接按钮,发起的websocket连接,可自行更改到其他合适的地方连接websocket

1.创建两个按钮,连接按钮,发送按钮

<view @click="connect()">连接</view>
<view @click="sendSocket()">发送</view>

2.定义事件,连接ws

//发送ws
sendSocket() {console.log('发送wx')uni.sendSocketMessage({data: JSON.stringify({name: 'PC',message: 'wx'})})
},
//连接ws
connect() {if (this.connected || this.connecting) {uni.showModal({content: '正在连接或者已经连接，请勿重复连接',showCancel: false,})return}this.connecting = trueuni.showLoading({title: '连接中...',})uni.connectSocket({url: 'ws://localhost:8888',success(res) {// 这里是接口调用成功的回调，不是连接成功的回调，请注意console.log('uni.connectSocket success', res)},fail(err) {// 这里是接口调用失败的回调，不是连接失败的回调，请注意console.log('uni.connectSocket fail', err)},})//监听WebSocket连接打开事件uni.onSocketOpen((res) => {console.log('监听中')if (this.pageVisible) {this.connecting = falsethis.connected = trueuni.hideLoading()uni.showToast({icon: 'none',title: '连接成功',})console.log('onOpen', res)uni.sendSocketMessage({data: JSON.stringify({name: 'WX',message: 'init'})})}})uni.onSocketError((err) => {console.log('onError', err)if (this.pageVisible) {this.connecting = falsethis.connected = falseuni.hideLoading()uni.showModal({content: '连接失败，可能是websocket服务不可用，请稍后再试',showCancel: false,})}})uni.onSocketMessage((res) => {console.log('接收到了通知', res)if (this.pageVisible) {this.msg = res.dataconsole.log('onMessage', res)}})uni.onSocketClose((res) => {if (this.pageVisible) {this.connected = falsethis.msg = ''console.log('onClose', res)}})
},