给对象添加监听的封装

<script src="prototype.js"></script>

<div id="myDiv">sssssssssssssssssssssss</div>
<script>
function Listener(el,eventType){
 this.listeners = new Array();
 this.el = el;
 el.obj = this;
 el[eventType] = this.callback;
}
Listener.prototype.notify = function(event){
 var listeners = this.listeners;
 for(var i=0;i<listeners.length;i++){
  var listener = listeners[i];
  listener.call(this,event);//this为Listener的指针
 }
}
Listener.prototype.callback = function(event){
 var e = event || window.event;
 var obj = this.obj;//this.obj为对象的指针
 obj.notify(e);
}
Listener.prototype.addListeners = function(f){
 this.listeners.push(f);
}
var obj = $("myDiv");
var s = new Listener(obj,"onclick");

s.addListeners(myAlert);
s.addListeners(myAlert1);

function myAlert(){
 alert(this.listeners);
}
function myAlert1(){
 alert("alert1");
}
</script>