您当前的位置：首页 > 计算机 > 编程开发 > Html+Div+Css（前端）

CSS Flex布局

时间：07-14来源：作者：点击数：22

1 百分比布局（流式布局）

<!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>京东</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }
        
        li {
            list-style: none;
        }
        
        .toolbar {
            position: fixed;
            left: 0;
            bottom: 0;
            /* 百分比布局  流式布局 */
            width: 100%;
            height: 50px;
            background-color: pink;
            border-top: 1px solid #ccc;
        }
        
        .toolbar li img {
            height: 100%;
        }

        .toolbar li {
            float: left;
            width: 20%;
            height: 50px;
        }
    </style>
</head>

<body>
    <div class="toolbar">
        <ul>
            <li>
                <a href="#"><img src="./images/index.png" alt=""></a>
            </li>
            <li>
                <a href="#"><img src="./images/classify.png" alt=""></a>
            </li>
            <li>
                <a href="#"><img src="./images/jd.png" alt=""></a>
            </li>
            <li>
                <a href="#"><img src="./images/car.png" alt=""></a>
            </li>
            <li>
                <a href="#"><img src="./images/login.png" alt=""></a>
            </li>
        </ul>
    </div>
</body>

</html>

2 Flex布局介绍

总结：

体验flex布局

<!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>体验flex布局</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }

        .box {
            display: flex;
            justify-content: space-between;
            /* height: 200px; */
            border: 1px solid #000;
        }

        .box div {
            /* float: left;
            margin: 10px; */
            width: 100px;
            height: 100px;
            background-color: pink;
        }
    </style>
</head>
<body>
    <div class="box">
        <div>1</div>
        <div>2</div>
        <div>3</div>
    </div>
</body>
</html>

作用：

<!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>体验flex布局</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }

        .box {
            /* 视觉效果: 子级一行排列/水平排列 */
            /* 水平排列: 默认主轴在水平, 弹性盒子都是沿着主轴排列 */
            display: flex;
            height: 200px;
            border: 1px solid #000;
        }

        .box div {
            width: 100px;
            height: 100px;
            background-color: pink;
        }
    </style>
</head>
<body>
    <div class="box">
        <div>1</div>
        <div>2</div>
        <div>3</div>
    </div>
</body>
</html>

3 主轴对齐方式

<!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>主轴对齐方式</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }

        .box {
            display: flex;

            /* 居中 */
            /* 在中间排列 */
            /* justify-content: center; */

            /* 间距在弹性盒子(子级)之间 */
            /* 左右顶格，除了左右，中间的间距都相等 */
            /* justify-content: space-between; */

            /* 所有间距都相等，包括左右到边界的距离 */
            /* justify-content: space-evenly; */

            /* 间距加在子级的两侧 */
            /* 视觉效果: 中间的间距是左右到边界间距的两倍 */
            justify-content: space-around;
            
            height: 200px;
            margin: auto;
            border: 1px solid #000;
        }
        
        .box div {
            width: 100px;
            height: 100px;
            background-color: pink;
        }
    </style>
</head>

<body>
    <div class="box">
        <div>1</div>
        <div>2</div>
        <div>3</div>
    </div>
</body>

</html>

4 侧轴对齐方式

<!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>侧轴对齐方式</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }

        .box {
            display: flex;

            /* 居中 */
            /* align-items: center; */

            /* 拉伸,默认值(现有状态,测试的时候去掉子级的高度) */
            align-items: stretch;

            height: 300px;
            margin: auto;
            border: 1px solid #000;
        }
        
        .box div {
            /* width: 100px; */
            /* height: 100px; */
            background-color: pink;
        }

        /* 单独设置某个弹性盒子的侧轴对齐方式 */
        .box div:nth-child(2) {
            align-self: center;
        }
        
    </style>
</head>

<body>
    <div class="box">
        <div>1111</div>
        <div>2</div>
        <div>3</div>
    </div>
</body>

</html>

5 伸缩比

<!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>
        * {
            margin: 0;
            padding: 0;
        }

        .box {
            display: flex;

            height: 300px;
            border: 1px solid #000;
        }

        .box div {
            height: 200px;
            margin: 0 20px;
            background-color: pink;
        }

        .box div:nth-child(1) {
            width: 50px;
        }

        .box div:nth-child(2) {
            /* 占用父级剩余尺寸的份数 */
            flex: 3;
        }

        .box div:nth-child(3) {
            flex: 1;
        }
        
    </style>
</head>
<body>
    <div class="box">
        <div>1</div>
        <div>2</div>
        <div>3</div>
    </div>
</body>
</html>

6 修改主轴方向

<!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>主轴方向</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }

        li {
            list-style: none;
        }

        .box li {
            display: flex;
            /* 1. 先确定主轴方向; 2. 再选择对应的属性实现主轴或侧轴的对齐方式 */
            /* 修改主轴方向: 列 */
            flex-direction: column;

            /* 视觉效果: 实现盒子水平居中 */
            align-items: center;

            /* 视觉效果: 垂直居中 */
            justify-content: center;
            

            width: 80px;
            height: 80px;
            border: 1px solid #ccc;
        }
        
        .box img {
            width: 32px;
            height: 32px;
        }
    </style>
</head>

<body>
    <div class="box">
        <ul>
            <li>
                <img src="./images/media.png" alt="">
                <span>媒体</span>
            </li>
        </ul>
    </div>
</body>

</html>

7 弹性盒子换行

<!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>弹性盒子换行</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }

        .box {
            display: flex;

            /* 默认值, 不换行 */
            /* flex-wrap: nowrap; */

            /* 弹性盒子换行 */
            flex-wrap: wrap;

            /* 调节行对齐方式 */
            /* align-content: center; */
            /* align-content: space-around; */
            align-content: space-between;

            height: 500px;
            border: 1px solid #000;
        }
        
        .box div {
            width: 100px;
            height: 100px;
            margin: 10px;
            background-color: pink;
        }
    </style>
</head>

<body>
    <div class="box">
        <div>1</div>
        <div>2</div>
        <div>3</div>
        <div>4</div>
        <div>5</div>
        <div>6</div>
        <div>7</div>
        <div>8</div>
    </div>
</body>

</html>