css弹性盒子——flex布局

编辑

一、flex容器的样式属性(父元素属性)

[display:flex 弹性盒子，实现水平排列,在父盒子设置，适用于单行/单列](#display:flex 弹性盒子，实现水平排列,在父盒子设置，适用于单行/单列)

justify-content

[4.flex组合属性 flex:flex-grow flex-shrink flex-basis；](#4.flex组合属性 flex:flex-grow flex-shrink flex-basis；)

5.order

[6.align-self 单独控制某个元素](#6.align-self 单独控制某个元素)

一、flex容器的样式属性(父元素属性)

display:flex 弹性盒子，实现水平排列,在父盒子设置，适用于单行/单列

默认子盒子宽高度超过父盒子时，按父盒子宽高度均分，再多则会溢出

flex和上面的block，inline，inline-block并列， display只能设置一个属性，display和float不能出现在同一个盒子的属性里。

flex-direction: column;flex-wrap:wrap; 等于 flex-flow: row wrap;

使用F12可快速调试各属性的页面效果

justify-content

justify-content:space-evenly;

justify-content:space-between;

justify-content: space-around;两侧的空间是中间元素间隔空间的一半

stretch(默认值)

align-items:baseline;

二、flex元素的样式属性(子元素属性)

1.flex-grow

单个盒子范围0~1 延伸至剩余空间的0~1

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>flex-grow</title>
    <style>
        .box{
            width: 500px;
            height: 300px;
            background-color: skyblue;
            display: flex;
        }
        .box div{
            width: 100px;
            height: 100px;
            background-color: pink;
            flex-grow: 0.6;
        }
    </style>
</head>
<body>
    <div class="box">
        <div>1</div>
    </div>
</body>
</html>

多个子盒子设置超过1时，剩余空间分成n份

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>flex-grow</title>
    <style>
        .box{
            width: 500px;
            height: 300px;
            background-color: skyblue;
            display: flex;
        }
        .box div:nth-of-type(1){
            width: 100px;
            height: 100px;
            background-color: pink;
            flex-grow: 3;
        }
        .box div:nth-of-type(2){
            width: 200px;
            height: 100px;
            background-color: green;
            flex-grow: 2;
        }
    </style>
</head>
<body>
    <div class="box">
        <div>1</div>
        <div>2</div>
    </div>
</body>
</html>

2.flex-shrink

收缩超出部分的0~1

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>flex-grow</title>
    <style>
        .box{
            width: 500px;
            height: 300px;
            background-color: skyblue;
            display: flex;
        }
        .box div:nth-of-type(1){
            width: 600px;
            height: 100px;
            background-color: pink;
            flex-shrink: 0.5;
        }
        /* .box div:nth-of-type(2){
            width: 200px;
            height: 100px;
            background-color: green;
        } */
    </style>
</head>
<body>
    <div class="box">
        <div>1</div>
        <!-- <div>2</div> -->
    </div>
</body>
</html>

3.flex-basis

设置主轴初始尺寸，0%(不起作用)，n px

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>flex-grow</title>
    <style>
        .box{
            width: 500px;
            height: 500px;
            background-color: skyblue;
            display: flex;
        }
        .box div:nth-of-type(1){
            width: 100px;
            height: 100px;
            background-color: pink;
            /* flex-shrink: 0.5; */
            flex-basis: 200px;
        }
        /* .box div:nth-of-type(2){
            width: 200px;
            height: 100px;
            background-color: green;
            flex-grow: 0.5;
        } */
    </style>
</head>
<body>
    <div class="box">
        <div>1</div>
        <!-- <div>2</div> -->
    </div>
</body>
</html>

4.flex组合属性 flex:flex-grow flex-shrink flex-basis；

flex:1; 表示1 1 0%

flex:0.5; 表示0.5 1 0%

5.order

顺序

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>flex-grow</title>
    <style>
        .box{
            width: 500px;
            height: 500px;
            background-color: skyblue;
            display: flex;
            /* flex-direction: column; */
        }
        .box div{
            width: 100px;
            height: 100px;
            background-color: pink;
            border: 1px solid black;
        }
        .box div:nth-of-type(1){
            order:1;
        }
        .box div:nth-of-type(1){
            order:-1;
        }
    </style>
</head>
<body>
    <div class="box">
        <div>1</div>
        <div>2</div>
        <div>3</div>
        <div>4</div>
    </div>
</body>
</html>

6.align-self 单独控制某个元素

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>flex-grow</title>
    <style>
        .box{
            width: 500px;
            height: 300px;
            background-color: skyblue;
            display: flex;
            /* flex-direction: column; */
        }
        /* .box div:nth-of-type(1){
            width: 100px;
            height: 100px;
            background-color: pink;
            flex-shrink: 0.5;
            flex-basis: 200px;
            flex:1;
        } */
        /* .box div:nth-of-type(2){
            width: 200px;
            height: 100px;
            background-color: green;
            flex-grow: 0.5;
        } */
        .box div{
            width: 100px;
            height: 100px;
            background-color: pink;
            border: 1px solid black;
        }
        /* .box div:nth-of-type(1){
            order:1;
        } */
        .box div:nth-of-type(4){
            align-self: flex-end;
        }
    </style>
</head>
<body>
    <div class="box">
        <div>1</div>
        <div>2</div>
        <div>3</div>
        <div>4</div>
    </div>
</body>
</html>