img 在层内 居中显示
div{width:250px;height:150px;background:#000;position:relative;} img{width:150px;position: absolute;left: 0;top: 0;right: 0;bottom: 0;margin: auto;}
<div><img src="https://www.baidu.com/img/baidu_jgylogo3.gif"/></div>
div{width:250px;height:150px;background:#000;position:relative;} img{width:150px;position: absolute;left: 0;top: 0;right: 0;bottom: 0;margin: auto;}
<div><img src="https://www.baidu.com/img/baidu_jgylogo3.gif"/></div>
