nodejs+express+socket.io

其实官网文档清楚了  https://socket.io/get-started/chat/

但是因为之前写的是nodejs+express, socket.io是后加的, 还是有小坑

服务器端:

官网代码

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

app.get('/', function(req, res){
  res.sendFile(__dirname + '/index.html');
});

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

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

注意这里是http.listen而不是app.listen!

如果是app.listen  客户端会打开web页面,  但一直报连不上socket.io 404 not found

2 注意它用的是 app.get('/')

也可以直接用1行static

// app.get("/", (req, res) => res.send("Hello World!"));

app.use(express.static(config['PATH_OVERLAY_STATIC']))

但必须注释掉app.get('/')

客户端:

const io = require('socket.io-client');
const socket = io();
io.on('connection', function(socket){
    console.log('connected with server!');
    socket.on('chat message', function(msg){
        console.log('message: ' + msg);
    });
   ...
});


window.onload = function() {
    ....
}

必须用socket.io-client否则会报错.

io.on 完全独立其他代码. 其实类似与int main()主函数,死循环.

// app.get("/", (req, res) => res.send("Hello World!"));

app. use(express. static(config[ 'PATH_OVERLAY_STATIC']))