方法1:绝对定位+margin:auto
.parent { width:800px; height:500px; border:2px solid #000; position:relative; } .child { width:200px; height:200px; margin: auto; position: absolute; top: 0; left: 0; bottom: 0; right: 0; background-color: red; }
方法2:display:table-cell
.parent { width:800px; height:500px; border:2px solid #000; display:table-cell; vertical-align:middle; text-align: center; } .child { width:200px; height:200px; display:inline-block; background-color: red; }
方法3:display:flex
.parent { width:800px; height:500px; border:2px solid #000; display:flex; justify-content:center; align-items:center; } .child { width:200px; height:200px; background-color: red; }
方法4:绝对定位+margin
.parent { width:800px; height:500px; border:2px solid #000; position:relative; } .child { width:300px; height:200px; margin:auto; position:absolute;/*设定水平和垂直偏移父元素的50%,再根据实际长度将子元素上左挪回一半大小*/
left:50%;
top:50%;
margin-left: -150px;
margin-top: -100px;
background-color: red;
}