zoukankan html css js c++ java

如何实现固定宽高的DOM元素的水平垂直居中

效果：

实现代码1：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style type="text/css">
        body{margin: 0; padding: 0;}
        #div1{
            margin-top: 100px;
            margin-left: 150px;
            width: 300px;
            height: 300px;
            background-color: red;
            position: relative;
        }
        #div2{
            width: 120px;
            height: 120px;
            background-color: black;
            position: absolute;
            /*(300-120)/2/300*/
            top: 30%;
            left: 30%;
        }
    </style>
</head>
<body>
    <div id="div1" class="classname">
        <div id="div2" class="classname">
        </div>
    </div>
</body>
</html>

实现代码2：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style type="text/css">
        body{margin: 0; padding: 0;}
        #div1{
            margin-top: 100px;
            margin-left: 150px;
            width: 300px;
            height: 300px;
            background-color: red;
        }
        #div2{
            width: 120px;
            height: 120px;
            background-color: black;
            /*(300-120)/2/300=30%*/
            position: relative;
            top: 30%;
            left: 30%;
        }
    </style>
</head>
<body>
    <div id="div1" class="classname">
        <div id="div2" class="classname">
        </div>
    </div>
</body>
</html>

实现代码3：

查看全文

相关阅读:
多按键设计的标准思路
 与，非，或门总结
 i2c中应答信号信号总结
 i2c中start和restart的区别
 poj 1631 Bridging signals
poj 2533 Longest Ordered Subsequence
poj 1887 Testing the CATCHER
poj 1088 滑雪
 poj 1014 Dividing
babel转码时generator的regeneratorRuntime

原文地址：https://www.cnblogs.com/arvintang/p/5433390.html