node.js events(EventEmitter對象)

var events = require(‘events’);
var eventEmitter = new events.EventEmitter();
var listener1 = function listener1(){
console.log(‘監聽器 listener1執行’);
};
var listener2 = function listener2(){
console.log(‘監聽器 listener2 執行’);
};
//綁定connection事件 處理函數爲listener1;
eventEmitter.addListener(‘connection’,listener1);
//綁定connection事件 處理函數爲listener2;
eventEmitter.on(‘connection’,listener2);

//發射connection 事件
eventEmitter.emit(‘connection’);
//移出綁定的listener1函數
eventEmitter.removeListener(‘connection’,listener1);
console.log(‘listener1不在監聽’);
//發射事件
eventEmitter.emit(‘connection’);
//listenerCount 返回註冊了指定事件的監聽數量
eventListeners = require(‘events’).EventEmitter.listenerCount(eventEmitter,’connection’);
console.log(eventListeners + ” 個監聽器監聽連接事件。”);

console.log(“程序執行完畢。”);