得到TypeError：无法读取未定义的属性'on'
在执行danielnill示例时出现以下错误
当我在这个例子中添加连接动作和客户端代码时，我得到了这个错误。
错误：
/home/oneadmin/Desktop/test-projects/nodejs/basic-example/server.js:40 io.sockets.on('connection', function(socket){ ^ TypeError: Cannot read property 'on' of undefined at Object.<anonymous> (/home/oneadmin/Desktop/test-projects/nodejs/basic-example/server.js:40:11) at Module._compile (module.js:449:26) at Object.Module._extensions..js (module.js:467:10) at Module.load (module.js:349:32) at Function.Module._load (module.js:305:12) at Function.Module.runMain (module.js:490:10) at startup (node.js:124:16) at node.js:807:3 server.js
var http = require("http"); var url = require('url'); var fs = require('fs'); var io = require('socket.io'); var server = http.createServer(function(request, response){ console.log('Connection'); var path = url.parse(request.url).pathname; switch(path){ case '/': response.writeHead(200, {'Content-Type': 'text/html'}); response.write('hello world'); response.end(); break; case '/socket.html': fs.readFile(__dirname + path, function(error, data){ if (error){ response.writeHead(404); response.write("opps this doesn't exist - 404"); } else{ response.writeHead(200, {"Content-Type": "text/html"}); response.write(data, "utf8"); } response.end(); }); break; default: response.writeHead(404); response.write("opps this doesn't exist - 404"); response.end(); break; } }); server.listen(8001); io.listen(server); io.sockets.on('connection', function(socket){ socket.emit('message', {'message': 'hello world'}); });
socket.html
<html> <head> <script src="/socket.io/socket.io.js"> </script> </head> <body> <script> var socket = io.connect(); socket.on('message', function(data){ console.log(data.message); }); </script> <div> This is our socket.html file</div> </body> </html>
请帮我理解错误，我该如何解决？
您将需要捕获socket.io的.listen()的结果来设置服务器端侦听器：
server.listen(8001); var ios = io.listen(server); ios.sockets.on('connection', function(socket){ socket.emit('message', {'message': 'hello world'}); });
sockets对象不是socket.io模块本身的成员，而是io.Manager()的监听实例。
在链接的文章中，其中一个代码段中存在拼写错误（在“ Adding Socket.io ”下）：
// ... var io.listen(server);
我假设这是为了：
var io = io.listen(server);