我尝试在几天内使用node.js和socket.io在网络上构建应用程序。我不明白为什么我无法使用socket.io 和服务器node.js 从客户端向服务器发送消息。我可以从服务器到客户端接收消息和事件。但无法从服务器接收客户端的事件。我认为我的库有问题。
我安装的模块node.js
- express
- io
- Jade
- 网络
- socket.io
- socket.io-client
为什么会有socket.io-client和socket.io？ 我什至尝试这个例子:code.google.com/p/nodejs-win/wiki/SimpleChatSystem 但还是不行。服务器无法接收来自客户端的任何消息和事件。
代码server.js
// Require HTTP module (to start server) and Socket.IO
var http = require('http'),
io = require('socket.io');
// Start the server at port 8080
var server = http.createServer(function(req, res){
// Send HTML headers and message
res.writeHead(200,{ 'Content-Type': 'text/html' });
res.end('<h1>Hello Socket Lover!</h1>');
});
server.listen(8080);
// Create a Socket.IO instance, passing it our server
var socket = io.listen(server);
// Add a connect listener
socket.on('connection', function(client){
console.log("server is start on port 8080");
// Create periodical which ends a message to the client every 5 seconds
var interval = setInterval(function() {
client.send('This is a message from the server! ' + new Date().getTime());
},5000);
// Success! Now listen to messages to be received
client.on('message',function(event){
console.log('Received message from client! ',event);
});
client.on('disconnect',function(){
clearInterval(interval);
console.log('Server has disconnected');
});
});
代码客户端index.html
<html>
<head>
<style>
* { margin:0; padding:0; font-size:11px; font-family:arial; color:#444; }
body { padding:20px; }
#message-list { list-style-type:none; width:300px; height:300px; overflow:auto; border:1px solid #999; padding:20px; }
#message-list li { border-bottom:1px solid #ccc; padding-bottom:2px; margin-bottom:5px; }
code { font-family:courier; background:#eee; padding:2px 4px; }
</style>
<script src="http://localhost:8080/socket.io/socket.io.js"></script>
<script>
// Create SocketIO instance
var socket = new io.connect('localhost',{
port: 8080
});
//socket.connect();
// Add a connect listener
socket.on('connect',function() {
log('<span style="color:green;">Client has connected to the server!</span>');
});
// Add connecting listener
socket.on('connecting',function() {
log('<span style="color:green;">Client is connecting to the server!</span>');
});
// Add a connect listener
socket.on('message',function(data) {
log('Received a message from the server: ' + data);
});
// Add a disconnect listener
socket.on('disconnect',function() {
log('<span style="color:red;">The client has disconnected!</span>');
});
// Sends a message to the server via sockets
function sendMessageToServer(message) {
socket.emit("message",message);
socket.send(message);
log('<span style="color:#888">Sending "' + message + '" to the server!</span>');
}
// Outputs to console and list
function log(message) {
var li = document.createElement('li');
li.innerHTML = message;
document.getElementById('message-list').appendChild(li);
}
setInterval(function(){ sendMessageToServer(new Date())},5000);
</script>
</head>
<body>
<p>Messages will appear below (and in the console).</p><br />
<ul id="message-list"></ul>
<ul style="margin:20px 0 0 20px;">
<li>Type <code>socket.disconnect()</code> to disconnect</li>
<li>Type <code>socket.connect()</code> to reconnect</li>
<li>Type <code>sendMessageToServer('Your Message')</code> to send a message to the server</li>
</ul>
</body>
</html>
最佳答案
此处错误:
// Sends a message to the server via sockets
function sendMessageToServer(message) {
socket.emit(message);
log('<span style="color:#888">Sending "' + message + '" to the server!</span>');
}
emit 方法需要两个参数。 第一个 - 事件代码。 第二个 - 事件数据。
正确的解决方案:
// Sends a message to the server via sockets
function sendMessageToServer(message) {
socket.emit('message', message);
log('<span style="color:#888">Sending "' + message + '" to the server!</span>');
}
关于node.js - 无法使用node.js和socket.io从客户端向服务器发送消息，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/14111311/