为什么我 chrome 和 IE 都没效果。
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>事件处理程序</title>
</head>
<body>
<div>
<input type="button" id="btn" value="按钮" >
</div>
<script type="text/javascript">
function showMes(){
alert('Hello World!');
}
var btn=document.getElementById('btn');
var eventUtil={
// 添加句柄
addHandler:function(element,type,handler){
if(element.addEventListener){
element.addEventListener(type,handler,false);
}else if(element.attachEvent){
element.attachEvent('on'+type,handler);
}else{
element['on'+type]=handler;
}
},
// 删除句柄
removeHandler:function(element,type,handler){
if(element.removeEventListener){
element.removeEventListener(type,handler,false);
}else if(element.detachEvent){
element.detachEvent('on'+type,handler);
}else{
element['on'+type]=null;
}
},
eventUtil.addHandler(btn,'click',showMes);
}
</script>
</body>
</html>
