<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<style type="text/css">
#div1{
400px;
height: 300px;
background: red;
display: none;
}
</style>
<script type="text/javascript">
//事件冒泡 事件会冒泡到他的父级 onclick事件会冒泡到它的父级
window.onload = function(){
var oBtn = document.getElementById("btn");
var oDiv = document.getElementById("div1");
oBtn.onclick = function(ev){
var oEvent = ev || event;
oDiv.style.display = "block";
oEvent.cancelBubble = true; //阻止事件冒泡
}
document.onclick = function(){
// alert("document被执行了");
oDiv.style.display = "none";
}
}
</script>
</head>
<body>
<input id="btn" type="button" value="按钮"/>
<div id="div1"></div>
</body>
</html>