垂直水平居中

1.已知宽高的元素的水平居中方案
方案一
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="font/style.css">
    <style type="text/css">
        * {
            margin: 0;
            padding: 0;
        }

        #wrap {
            position: relative;
            background-color: pink;
            width: 400px;
            height: 600px;
            margin: 0 auto;
        }

        #inner {
            width: 100px;
            height: 100px;
            background-color: orangered;
            position: absolute;
            left: 50%;
            top: 50%;
            margin-left: -50px;
            margin-top: -50px;
        }
    </style>
</head>
<body>
<div id="wrap">
    <div id="inner">
        test
    </div>
</div>
</body>
</html>
方案二
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="font/style.css">
    <style type="text/css">
        * {
            margin: 0;
            padding: 0;
        }

        #wrap {
            position: relative;
            background-color: pink;
            width: 400px;
            height: 600px;
            margin: 0 auto;
        }

        #inner {
            width: 100px;
            height: 100px;
            background-color: dodgerblue;
            position: absolute;
            left: 0;
            top: 0;
            right: 0;
            bottom: 0;
            margin: auto;
        }
    </style>
</head>
<body>
<div id="wrap">
    <div id="inner">
        test
    </div>
</div>
</body>
</html>

绝对定位盒子特性：
1.水平方向：left+right+width+padding+margin=包含块padding区域尺寸
2.垂直方向：top+bottom+height+padding+margin=包含块padding区域尺寸

2.未知宽高的元素的水平居中方案
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="font/style.css">
    <style type="text/css">
        * {
            margin: 0;
            padding: 0;
        }

        #wrap {
            position: relative;
            background-color: pink;
            width: 400px;
            height: 600px;
            margin: 0 auto;
        }

        #inner {
            background-color: dodgerblue;
            position: absolute;
            left: 50%;
            top: 50%;
            transform: translate3d(-50%, -50%, 0);
            margin: auto;
        }
    </style>
</head>
<body>
<div id="wrap">
    <div id="inner">
        test
    </div>
</div>
</body>
</html>
posted @ 2020-02-10 20:57  kanaliya  阅读(95)  评论(0)    收藏  举报