<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>handler</title>
</head>
<body>
<button id="btn">click</button>
<script>
var EventUtil = {
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;
}
},
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;
}
}
};
var handler = function() {
console.log('handler');
};
var oBtn = document.getElementById('btn');
EventUtil.addHandler(oBtn, 'click', handler);
EventUtil.removeHandler(oBtn, 'click', handler);
</script>
</body>
</html>
