css设置图片的高等于图片的高

<div class="box"> ???????????????????<img src="img/2222.jpg" /></div>

.box { ???position: relative; ???width: 100%; ???height: 0; ???padding-bottom: 100%;} ???????.box img { ???position: absolute; ???top: 0; ???left: 0; ???width: 100%; ???height: 100%;}