Question

我在实施danielnill示例

时遇到以下错误

当我在此示例中添加连接操作和客户端代码时，我收到此错误。

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>

请帮助我理解错误，我该如何解决？

Answer 1

您需要捕获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()的侦听实例的成员。

在您关联的帖子中，其中一个片段中存在拼写错误（在“添加Socket.io ”下）：

// ...

var io.listen(server);

我认为那应该是：

var io = io.listen(server);

get TypeError：无法读取未定义的属性'on'

1 个答案: