- 已知宽高的情况下
div{
width: 200px;
height: 200px;
background: green;
//方法一
position: absolute;
left: 0;
right: 0;
bottom: 0;
top: 0;
margin: auto;
//方法二
position: absolute;
left: 50%;/*定位父容器的50%*/
top: 50%;
margin-left: -100px;
margin-right: -100px;
}
2.宽高未知的情况下,使用绝对定位transform
position: absolute;
left: 50%;/*定位父容器的50%*/
top: 50%;
transform: translate(-50%,-50%);
3.flex弹性布局
/*父容器设置为flex*/
display: flex;
width: 100%;
height: 100vh;
justify-content: center;
align-items: center;
4.table布局
.wrap{
width: 100%;
height: 100vh;
display: table;
}
.item {
display: table-cell;
vertical-align: middle;
text-align: center;
}
