//div的id为box #box{ width:200px; heighti:200px; border:1px solid #f00; //重点是以下规则 position:absolute; top:0px; left:0px; bottom:0px; right:0px; margin:auto; }
//div的id为box #box{ width:200px; heighti:200px; border:1px solid #f00; //重点是以下规则 position:absolute; top:0px; left:0px; bottom:0px; right:0px; margin:auto; }