<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>垂直居中--图片自适应宽高</title>
<style type="text/css">
/* 方法一 定位 为了看效果就加上了背景 宽高*/
.wrap{
position: relative;
width: 200px;
height: 200px;
background: #000;
}
.box{
position: absolute;
top: 50%;
left: 50%;
background: #999;
width: 100px;
height: 100px;
transform: translate(-50%,-50%);
}
/* 方法二 flex布局 */
.wrap{
display: flex;
justify-content: center;
align-items: center;
width: 200px;
height: 200px;
background: #000;
}
.box{
background: #999;
width: 100px;
height: 100px;
}
/* 图片自适应宽高 */
img{
max-width: 100%;
max-height: 100%;
}
</style>
</head>
<body>
<div class="wrap">
<div class="box">
<img src="https://f11.baidu.com/it/u1=2936607031&u2=3595029289&fm=76" >
</div>
</div>
</body>
</html>