nercon 2020-02-22
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>absoulue与relative配合定位盒子居中问题</title>
<style type="text/css">
*{
margin: 0;
background-color: yellow;
}
/* 如何把-一个盒子放到页面中央 */
.box{
width: 100px;
height: 100px;
background-color: blue;
position: absolute;
left: 50%;
bottom: 50%;
margin-top: -50px;
margin-left: -50px;
z-index: 2;
}
/*2.如何把2个div块同时居中*/
.div1{
width: 500px;
height: 300px;
background-color: red;
position: absolute; ;
left: 50%;
top: 50%;
/*居中的只是一个点,所以需要往左走250,往上走150*/
margin-left: -250px;
margin-top: -150px;
}
.div2{
width: 200px;
height: 100px;
background-color:green;
position: absolute;
top: 50%;
left: 50%;
margin-left: -100px;
margin-top: -50px;
}
</style>
<script>
window.onload=function(){
var obj=document.getElementById(‘ceshi‘)
obj.onclick=function(){
console.log(‘123‘);
alert(‘我一直在寻找找到了你便找到了整个世界‘)
}
}
</script>
</head>
<body>
<div class="box" id="ceshi"></div>
<div class="div1">
<div class="div2">
</div>
</div>
</body>
</html>