eventListener.html

<html>

<head>
    <title>实现JS添加事件，并且this 指向Dom元素,兼容不同浏览器</title>
    <script src='command.js'></script>
</head>

<body>
    <input type="button" id='bt' value='Click' data-msg='This is a message for button'>
    <script>
    var obj = document.getElementById('bt');
    addEventlistener(obj, 'click', function(e) {
    	// IE6,7,8 this 指向Windows ，所有不能直接用This，通过Event获取目标元素
        e = e || window.event;
        var _this = e.srcElement || e.target;
        alert(_this.id + ";");
    })

    function addEventlistener(obj, type, cb) {
        if (obj.addEventListener) {
            obj.addEventListener(type, cb);
        } else {
            obj.attachEvent('on' + type, cb);
        }
    }

    function addEvent(elem,type,handler){
        if(elem.addEventListener){
            elem.addEventlistener(type,handler,false);
        }else if(elem.attachEvent){
            elem['temp'+type+handler]=handler;
            elem[type+handler]=function{
                elem['temp'+type+handler].apply(elem);
            }
            elem.attachEvent('on'+type,elem[type+handler]);
        }else{
            elem['on'+type]=handler
        }
    }
    </script>
</body>

</html>