水平垂直居中-优快云博客

本文链接：https://blog.youkuaiyun.com/ShaQiMa_/article/details/118615583

方法一：position+margin

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box{
            width: 200px;
            height: 200px;
            background-color: aqua;
            position: relative;
        }
        .content{
            width: 100px;
            height: 100px;
            background-color: black;
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            margin: auto;
        }
    </style>
</head>
<body>
    <div class="box">
        <div class="content"></div>
    </div>
</body>
</html>

方法二：position+transform

        .box{
            width: 200px;
            height: 200px;
            background-color: aqua;
            position: relative;
        }
        .content{
            width: 100px;
            height: 100px;
            background-color: black;
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%,-50%);
        }

方法三：position+margin（需要知道子元素宽高）

        .box{
            width: 200px;
            height: 200px;
            background-color: aqua;
            position: relative;
        }
        .content{
            width: 100px;
            height: 100px;
            background-color: pink;
            position: absolute;
            top: 50%;
            left: 50%;
            margin-left: -50px;
            margin-top: -50px;
        }

方法四： flex

        .box{
            width: 200px;
            height: 200px;
            background-color: green;
            display: flex;
            justify-content: center;
            align-items: center;
        }
        .content{
            width: 100px;
            height: 100px;
            background-color: pink;
        }

方法五： position+calc

        .box{
            width: 200px;
            height: 200px;
            background-color: green;
            position: relative;
        }
        .content{
            width: 100px;
            height: 100px;
            background-color: pink;
            position: absolute;
            top: calc(50% - 50px);
            left:calc(50% - 50px);
        }

方法六：line-height+vertical-align

        .box{
            width: 200px;
            height: 200px;
            background-color: blue;
            line-height: 200px;
            text-align: center;
        }
        .content{
            width: 100px;
            height: 100px;
            background-color: pink;
            display: inline-block;
            vertical-align: middle;
        }