Js事件监听封装（支持匿名函数）

先看demo：http://liutian1937.github.io/demo/EventListen.html
/*绑定事件与取消绑定*/
var handleHash = {};
var bind = (function() {
    if (window.addEventListener) {
        return function(el, type, fn, capture) {
            el.addEventListener(type, function(){
                fn();
                handleHash[type] = handleHash[type] || [];
                handleHash[type].push(arguments.callee);
            }, capture);
        };
    } else if (window.attachEvent) {
        return function(el, type, fn, capture) {
            el.attachEvent("on" + type, function(){
                fn();
                handleHash[type] = handleHash[type] || [];
                handleHash[type].push(arguments.callee);
            });
        };
    }
})();
var unbind = (function(){
    if (window.addEventListener) {
        return function(el, type ) {
            if(handleHash[type]){
                var i = 0, len = handleHash[type].length;
                for (i; i<len ; i += 1){
                    el.removeEventListener(type, handleHash[type][i]);
                }
            };
        };
    } else if (window.attachEvent) {
        return function(el, type) {
            if(handleHash[type]){
                var i = 0, len = handleHash[type].length;
                for (i; i<len ; i += 1){
                    el.detachEvent("on" + type, handleHash[type][i]);
                }
            };
        };
    }
})();

原理解析：

handleHash做哈希表缓存事件的function，handleHash['事件名称']是一个数组，来添加多个事件监听的方法，unbind哪个事件的时候遍历handleHash['事件名称']的数组，然后移除。

bind(obj,'click',function(){
    alert ('click');
});
unbind(obj,'click');