JS模拟事件委托。。。

<script type="text/javascript">
var Delegate = function () {
    this.array = [];
};

Delegate.prototype = {

    constructor : Delegate
   
    , add : function (a, b) {
        this.array[this.array.length] = function () {
            b.apply(a, Array.prototype.slice.call(arguments));
        };
    }
   
    , del : function (num) {
        if (num < this.array.length) this.array.splice(num, 1);
    }
   
    , exec : function () {
        var arg = Array.prototype.slice.call(arguments), i = 0;
       
        for (; i < this.array.length ;) this.array[i ++].apply(null, arg);
    }
   
    , detach : function () {
        var i = 0;
       
        for (; i < this.array.length ;) this.array[i ++] = null;
       
        this.array = null;
    }

};

var Class = function (n) {
    this.name = n;
};

Class.prototype.showName = function () {
    alert(this.name + "/n参数A：" + arguments[0] + "/n参数B：" + arguments[1]);
};

var delegateObj = new Delegate;

var a = new Class("a对象");
var b = new Class("b对象");
var c = new Class("c对象");

delegateObj.add(a, a.showName); //添加委托
delegateObj.add(c, c.showName);
delegateObj.add(b, b.showName);
delegateObj.del(1); //删除中间的即c
delegateObj.exec("第一个参数", "第二个参数"); //执行
delegateObj.detach();
delegateObj = null;
</script>