文章目录 【移动Web开发之flex布局】前端小抄(17)一、flex布局体验1.1 传统布局与flex布局1.2 初体验 二、flex布局原理2.1 布局原理 三、flex布局父项常见属性3.1 常见父项属性3.2 flex-direction设置主轴的方向3.3 justify-content设置主轴上的子元素排列方式3.4 flex-wrap设置子元素是否换行3.5 align-items设置侧轴上的子元素排列方式(单行)3.6 align-content 设置侧轴上的子元素的排列方式(多行)3.7 align-content和align-items区别3.8 flex-flow 四、flex布局子项常见属性4.1 flex属性4.2 align-self控制子项自己在侧轴上的排列方式4.3 order属性定义项目的排列顺序 五、携程网首页案例制作 【移动Web开发之flex布局】前端小抄(17)
本学习笔记是个人对 Pink 老师课程的总结归纳,转载请注明出处!
一、flex布局体验 1.1 传统布局与flex布局【传统布局】
兼容性好布局繁琐局限性,不能在移动端很好的布局【flex布局】
操作方便,布局极为简单,移动端应用很广泛PC 端浏览器支持情况较差IE11 或更低版本,不支持或仅部分支持建议:
如果是 PC 端页面布局,我们还是建议使用传统布局如果是移动端或者不考虑兼容性问题的 PC 端页面布局,我们还是使用 flex 弹性布局 1.2 初体验 <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>01-flex布局体验</title> <style> div { display: flex; width: 80%; height: 300px; background-color: pink; } div span { /* 弹性布局中:行内盒子的宽高可直接设置了 */ /* 免去了浮动的设置,以及对父盒子清除浮动的麻烦 */ width: 150px; height: 100px; background-color: black; margin-right: 5px; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> </div> </body> </html>等间距分布
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>01-flex布局体验</title> <style> div { display: flex; width: 80%; height: 300px; background-color: pink; justify-content: space-around; } div span { /* 弹性布局中:行内盒子的宽高可直接设置了 */ width: 150px; height: 100px; background-color: black; margin-right: 5px; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> </div> </body> </html>平均分为三等分
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>01-flex布局体验</title> <style> div { display: flex; width: 80%; height: 300px; background-color: pink; justify-content: space-around; } div span { /* 弹性布局中:行内盒子的宽高可直接设置了 */ /* width: 150px; */ height: 100px; background-color: black; margin-right: 5px; flex: 1; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> </div> </body> </html> 二、flex布局原理 2.1 布局原理flex 是 flexible Box 的缩写,意为“弹性布局”,用来为盒状模型提供最大的灵活性,任何一个容器都可以指定为 flex 布局。
当我们为父盒子设为 flex 布局以后,子元素的 float、clear 和 vertical-align 属性将失效。伸缩布局 = 弹性布局 = 伸缩盒布局 = 弹性盒布局 = flex 布局采用 flex 布局的元素,称为 flex 容器(flex container),简称“容器”。它的所有子元素自动成为容器成员,称为 flex 项目(flex item),简称“项目”。
上面的体验中 div 就是 flex 父容器上面的体验中 span 就是子容器 flex 项目子容器可以横向排列也可以纵向排列【子容器横向排列时的图示】
【总结 flex 布局原理】
就是通过给父盒子添加 flex 属性,来控制子盒子的位置和排列方式。
三、flex布局父项常见属性 3.1 常见父项属性以下由 6 个属性是对父元素设置的
flex-direction:设置主轴的方向justify-content:设置主轴上的子元素排列方式flex-wrap:设置子元素是否换行align-content:设置侧轴上的子元素的排列方式(多行)align-items:设置侧轴上的子元素排列方式(单行)flex-flow:复合属性,相当于同时设置了 flex-direction 和 flex-wrap 3.2 flex-direction设置主轴的方向(1)主轴与侧轴
在 flex 布局中,是分为主轴和侧轴两个方向,同样的叫法有:行 和 列、x轴 和 y轴
默认主轴方向就是 x轴 方向,水平向右默认侧轴方向就是 y轴 方向,水平向下(2)属性值
flex-direction 属性决定主轴的方向(即:项目的排列方向)
注意:主轴和侧轴是会变化的,就看 flex-direction 设置谁为主轴,剩下的就是侧轴。而我们的子元素是跟着主轴来排列的。
【案例】
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>02-flex主轴方向</title> <style> div { /* 给父级添加flex属性 */ display: flex; width: 800px; height: 300px; background-color: pink; /* 默认的主轴是 x 轴,那么 y 轴就是侧轴喽 */ /* 我们的元素是跟着主轴来排列的 */ flex-direction: row; /* 简单了解翻转即可 */ /* flex-direction: row-reverse; */ /* 我们可以把我们的主轴设置为 y 轴 那么 x 轴就成了侧轴 */ /* flex-direction: column; */ } div span { width: 150px; height: 100px; background-color: purple; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> </div> </body> </html> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>02-flex主轴方向</title> <style> div { /* 给父级添加flex属性 */ display: flex; width: 800px; height: 300px; background-color: pink; /* 默认的主轴是 x 轴,那么 y 轴就是侧轴喽 */ /* 我们的元素是跟着主轴来排列的 */ /* flex-direction: row; */ /* 简单了解翻转即可 */ flex-direction: row-reverse; /* 我们可以把我们的主轴设置为 y 轴 那么 x 轴就成了侧轴 */ /* flex-direction: column; */ } div span { width: 150px; height: 100px; background-color: purple; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> </div> </body> </html> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>02-flex主轴方向</title> <style> div { /* 给父级添加flex属性 */ display: flex; width: 800px; height: 300px; background-color: pink; /* 默认的主轴是 x 轴,那么 y 轴就是侧轴喽 */ /* 我们的元素是跟着主轴来排列的 */ /* flex-direction: row; */ /* 简单了解翻转即可 */ /* flex-direction: row-reverse; */ /* 我们可以把我们的主轴设置为 y 轴 那么 x 轴就成了侧轴 */ flex-direction: column; } div span { width: 150px; height: 100px; background-color: purple; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> </div> </body> </html> 3.3 justify-content设置主轴上的子元素排列方式justify-content 属性定义了项目在主轴上的对齐方式
注意:使用这个属性之前一定要确定好主轴是哪个!
【案例】
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>03-flex设置主轴上的子元素排列方式1</title> <style> div { display: flex; width: 800px; height: 300px; background-color: pink; /* 默认的主轴是 x轴 row */ flex-direction: row; /* justify-content: 是设置主轴上子元素的排列方式 */ /* 从头部开始,如果主轴是 x轴,则从左到右(默认值) */ justify-content: flex-start; /* 从尾部开始排列 */ /* justify-content: flex-end; */ /* 让我们子元素居中对齐 */ /* justify-content: center; */ /* 平分剩余空间 */ /* justify-content: space-around; */ /* 先两边贴边,在分配剩余的空间 */ /* justify-content: space-between; */ } div span { width: 150px; height: 100px; background-color: gray; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> <span>4</span> </div> </body> </html> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>03-flex设置主轴上的子元素排列方式1</title> <style> div { display: flex; width: 800px; height: 300px; background-color: pink; /* 默认的主轴是 x轴 row */ flex-direction: row; /* justify-content: 是设置主轴上子元素的排列方式 */ /* 从头部开始,如果主轴是 x轴,则从左到右(默认值) */ /* justify-content: flex-start; */ /* 从尾部开始排列 */ justify-content: flex-end; /* 让我们子元素居中对齐 */ /* justify-content: center; */ /* 平分剩余空间 */ /* justify-content: space-around; */ /* 先两边贴边,在分配剩余的空间 */ /* justify-content: space-between; */ } div span { width: 150px; height: 100px; background-color: gray; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> <span>4</span> </div> </body> </html> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>03-flex设置主轴上的子元素排列方式1</title> <style> div { display: flex; width: 800px; height: 300px; background-color: pink; /* 默认的主轴是 x轴 row */ flex-direction: row; /* justify-content: 是设置主轴上子元素的排列方式 */ /* 从头部开始,如果主轴是 x轴,则从左到右(默认值) */ /* justify-content: flex-start; */ /* 从尾部开始排列 */ /* justify-content: flex-end; */ /* 让我们子元素居中对齐 */ justify-content: center; /* 平分剩余空间 */ /* justify-content: space-around; */ /* 先两边贴边,在分配剩余的空间 */ /* justify-content: space-between; */ } div span { width: 150px; height: 100px; background-color: gray; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> <span>4</span> </div> </body> </html> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>03-flex设置主轴上的子元素排列方式1</title> <style> div { display: flex; width: 800px; height: 300px; background-color: pink; /* 默认的主轴是 x轴 row */ flex-direction: row; /* justify-content: 是设置主轴上子元素的排列方式 */ /* 从头部开始,如果主轴是 x轴,则从左到右(默认值) */ /* justify-content: flex-start; */ /* 从尾部开始排列 */ /* justify-content: flex-end; */ /* 让我们子元素居中对齐 */ /* justify-content: center; */ /* 平分剩余空间 */ justify-content: space-around; /* 先两边贴边,在分配剩余的空间 */ /* justify-content: space-between; */ } div span { width: 150px; height: 100px; background-color: gray; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> <span>4</span> </div> </body> </html> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>03-flex设置主轴上的子元素排列方式1</title> <style> div { display: flex; width: 800px; height: 300px; background-color: pink; /* 默认的主轴是 x轴 row */ flex-direction: row; /* justify-content: 是设置主轴上子元素的排列方式 */ /* 从头部开始,如果主轴是 x轴,则从左到右(默认值) */ /* justify-content: flex-start; */ /* 从尾部开始排列 */ /* justify-content: flex-end; */ /* 让我们子元素居中对齐 */ /* justify-content: center; */ /* 平分剩余空间 */ /* justify-content: space-around; */ /* 先两边贴边,在分配剩余的空间 */ justify-content: space-between; } div span { width: 150px; height: 100px; background-color: gray; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> <span>4</span> </div> </body> </html>注意:以上例子并不能根据浏览器窗口大小自动调整子项之间的间距,因为父盒子的宽度是固定死 800px 的,假如我们把父盒子宽度设为 80%,那么就可以有效果了。
【以上到下为主轴的案例】
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>04-flex设置主轴上的子元素排列方式2</title> <style> div { display: flex; width: 800px; height: 400px; background-color: pink; /* 我们现在的主轴是 y轴 */ flex-direction: column; /* justify-content: 是设置主轴上子元素的排列方式 */ /* 从头部开始,则从上到下(默认值) */ justify-content: flex-start; /* 从下开始排列 */ /* justify-content: flex-end; */ /* 让我们子元素垂直居中对齐 */ /* justify-content: center; */ /* 平分剩余空间 */ /* justify-content: space-around; */ /* 先上下两边贴边,在分配剩余的空间 */ /* justify-content: space-between; */ } div span { width: 150px; height: 100px; background-color: gray; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> </div> </body> </html> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>04-flex设置主轴上的子元素排列方式2</title> <style> div { display: flex; width: 800px; height: 400px; background-color: pink; /* 我们现在的主轴是 y轴 */ flex-direction: column; /* justify-content: 是设置主轴上子元素的排列方式 */ /* 从头部开始,则从上到下(默认值) */ /* justify-content: flex-start; */ /* 从下开始排列 */ justify-content: flex-end; /* 让我们子元素垂直居中对齐 */ /* justify-content: center; */ /* 平分剩余空间 */ /* justify-content: space-around; */ /* 先上下两边贴边,在分配剩余的空间 */ /* justify-content: space-between; */ } div span { width: 150px; height: 100px; background-color: gray; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> </div> </body> </html> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>04-flex设置主轴上的子元素排列方式2</title> <style> div { display: flex; width: 800px; height: 400px; background-color: pink; /* 我们现在的主轴是 y轴 */ flex-direction: column; /* justify-content: 是设置主轴上子元素的排列方式 */ /* 从头部开始,则从上到下(默认值) */ /* justify-content: flex-start; */ /* 从下开始排列 */ /* justify-content: flex-end; */ /* 让我们子元素垂直居中对齐 */ justify-content: center; /* 平分剩余空间 */ /* justify-content: space-around; */ /* 先上下两边贴边,在分配剩余的空间 */ /* justify-content: space-between; */ } div span { width: 150px; height: 100px; background-color: gray; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> </div> </body> </html>盒子自动垂直居中的困扰终于解决啦!!!
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>04-flex设置主轴上的子元素排列方式2</title> <style> div { display: flex; width: 800px; height: 400px; background-color: pink; /* 我们现在的主轴是 y轴 */ flex-direction: column; /* justify-content: 是设置主轴上子元素的排列方式 */ /* 从头部开始,则从上到下(默认值) */ /* justify-content: flex-start; */ /* 从下开始排列 */ /* justify-content: flex-end; */ /* 让我们子元素垂直居中对齐 */ /* justify-content: center; */ /* 平分剩余空间 */ justify-content: space-around; /* 先上下两边贴边,在分配剩余的空间 */ /* justify-content: space-between; */ } div span { width: 150px; height: 100px; background-color: gray; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> </div> </body> </html> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>04-flex设置主轴上的子元素排列方式2</title> <style> div { display: flex; width: 800px; height: 400px; background-color: pink; /* 我们现在的主轴是 y轴 */ flex-direction: column; /* justify-content: 是设置主轴上子元素的排列方式 */ /* 从头部开始,则从上到下(默认值) */ /* justify-content: flex-start; */ /* 从下开始排列 */ /* justify-content: flex-end; */ /* 让我们子元素垂直居中对齐 */ /* justify-content: center; */ /* 平分剩余空间 */ /* justify-content: space-around; */ /* 先上下两边贴边,在分配剩余的空间 */ justify-content: space-between; } div span { width: 150px; height: 100px; background-color: gray; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> </div> </body> </html> 3.4 flex-wrap设置子元素是否换行默认情况下,项目都排在一条线(又称“轴线”)上。flex-wrap 属性定义,flex 布局中默认是不换行的。
【案例】
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>05-flex-wrap子元素是否换行</title> <style> div { display: flex; width: 600px; height: 400px; background-color: pink; /* flex布局中,默认的子元素是不换行的, 如果装不开,会缩小子元素的宽度,放到父元素里面 */ /* flex-wrap: nowrap; */ /* 自动换行 */ /* flex-wrap: wrap; */ } div span { width: 150px; height: 100px; background-color: gray; color: #fff; margin: 10px; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> <span>4</span> <span>5</span> <span>6</span> </div> </body> </html> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>05-flex-wrap子元素是否换行</title> <style> div { display: flex; width: 600px; height: 400px; background-color: pink; /* flex布局中,默认的子元素是不换行的, 如果装不开,会缩小子元素的宽度,放到父元素里面 */ /* flex-wrap: nowrap; */ /* 自动换行 */ flex-wrap: wrap; } div span { width: 150px; height: 100px; background-color: gray; color: #fff; margin: 10px; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> <span>4</span> <span>5</span> <span>6</span> </div> </body> </html> 3.5 align-items设置侧轴上的子元素排列方式(单行)该属性是控制子项在侧轴(默认是 y轴)上的排列方式,在子项为单项(单行)的时候使用。
【案例】
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>06-flex设置侧轴上的子元素排列方式</title> <style> div { display: flex; width: 800px; height: 400px; background-color: pink; /* 默认的主轴是 x轴 row */ flex-direction: row; justify-content: center; /* 设置侧轴:从上到下 */ align-items: flex-start; } div span { width: 150px; height: 100px; background-color: gray; color: #fff; margin: 10px; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> </div> </body> </html> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>06-flex设置侧轴上的子元素排列方式</title> <style> div { display: flex; width: 800px; height: 400px; background-color: pink; /* 默认的主轴是 x轴 row */ flex-direction: row; justify-content: center; /* 设置侧轴:从下到上 */ align-items: flex-end; } div span { width: 150px; height: 100px; background-color: gray; color: #fff; margin: 10px; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> </div> </body> </html> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>06-flex设置侧轴上的子元素排列方式</title> <style> div { display: flex; width: 800px; height: 400px; background-color: pink; /* 默认的主轴是 x轴 row */ flex-direction: row; justify-content: center; /* 设置侧轴:挤在一起居中 */ align-items: center; } div span { width: 150px; height: 100px; background-color: gray; color: #fff; margin: 10px; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> </div> </body> </html> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>06-flex设置侧轴上的子元素排列方式</title> <style> div { display: flex; width: 800px; height: 400px; background-color: pink; /* 默认的主轴是 x轴 row */ flex-direction: row; justify-content: center; /* 设置侧轴:拉伸(默认) */ align-items: stretch; } div span { width: 150px; /* 拉伸的前提是没有指定高度 */ /* height: 100px; */ background-color: gray; color: #fff; margin: 10px; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> </div> </body> </html>align-items 只能统一对侧轴上的子元素排列方式,假如有多行子元素,要分别对不同的行设置不同的排列方式,那么此种方式就无法做了。
3.6 align-content 设置侧轴上的子元素的排列方式(多行)设置子项在侧轴上的排列方式并且只能用于子项出现 换行 的情况(多行),在单行下是没有效果的。
【案例】
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>07-flex设置侧轴上的子元素排列方式(多行)</title> <style> div { display: flex; width: 800px; height: 400px; background-color: pink; /* 换行 */ flex-wrap: wrap; /* 因为有了换行,此时我们侧轴上控制子元素的对齐方式我们用 align-content */ align-content: flex-start; /* align-content: center; */ /* align-content: space-around; */ /* align-content: space-between; */ /* align-content: stretch; */ } div span { width: 150px; height: 100px; background-color: gray; color: #fff; margin: 10px; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> <span>4</span> <span>5</span> <span>6</span> <span>7</span> <span>8</span> </div> </body> </html> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>07-flex设置侧轴上的子元素排列方式(多行)</title> <style> div { display: flex; width: 800px; height: 400px; background-color: pink; /* 换行 */ flex-wrap: wrap; /* 因为有了换行,此时我们侧轴上控制子元素的对齐方式我们用 align-content */ /* align-content: flex-start; */ align-content: center; /* align-content: space-around; */ /* align-content: space-between; */ /* align-content: stretch; */ } div span { width: 150px; height: 100px; background-color: gray; color: #fff; margin: 10px; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> <span>4</span> <span>5</span> <span>6</span> <span>7</span> <span>8</span> </div> </body> </html> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>07-flex设置侧轴上的子元素排列方式(多行)</title> <style> div { display: flex; width: 800px; height: 400px; background-color: pink; /* 换行 */ flex-wrap: wrap; /* 因为有了换行,此时我们侧轴上控制子元素的对齐方式我们用 align-content */ /* align-content: flex-start; */ /* align-content: center; */ align-content: space-around; /* align-content: space-between; */ /* align-content: stretch; */ } div span { width: 150px; height: 100px; background-color: gray; color: #fff; margin: 10px; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> <span>4</span> <span>5</span> <span>6</span> <span>7</span> <span>8</span> </div> </body> </html> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>07-flex设置侧轴上的子元素排列方式(多行)</title> <style> div { display: flex; width: 800px; height: 400px; background-color: pink; /* 换行 */ flex-wrap: wrap; /* 因为有了换行,此时我们侧轴上控制子元素的对齐方式我们用 align-content */ /* align-content: flex-start; */ /* align-content: center; */ /* align-content: space-around; */ align-content: space-between; /* align-content: stretch; */ } div span { width: 150px; height: 100px; background-color: gray; color: #fff; margin: 10px; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> <span>4</span> <span>5</span> <span>6</span> <span>7</span> <span>8</span> </div> </body> </html> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>07-flex设置侧轴上的子元素排列方式(多行)</title> <style> div { display: flex; width: 800px; height: 400px; background-color: pink; /* 换行 */ flex-wrap: wrap; /* 因为有了换行,此时我们侧轴上控制子元素的对齐方式我们用 align-content */ /* align-content: flex-start; */ /* align-content: center; */ /* align-content: space-around; */ /* align-content: space-between; */ align-content: stretch; } div span { width: 150px; height: 100px; background-color: gray; color: #fff; margin: 10px; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> <span>4</span> <span>5</span> <span>6</span> <span>7</span> <span>8</span> </div> </body> </html> 3.7 align-content和align-items区别 align-items 适用于单行情况下,只有上对齐、下对齐、居中和拉伸align-content 适应于换行(多行)的情况下(单行情况下无效),可以设置上对齐、下对齐、居中、拉伸以及平均分配剩余空间等属性值总结就是单行找 align-items 多行找 align-content 3.8 flex-flowflex-flow 属性是 flex-direction 和 flex-wrap 属性的复合属性
flex-flow: row wrap;
flex-direction:设置主轴的方向justify-content:设置主轴上的子元素排列方式flex-wrap:设置子元素是否换行align-content:设置侧轴上的子元素的排列方式(多行)align-items:设置侧轴上的子元素排列方式(单行)flex-flow:复合属性,相当于同时设置了 flex-direction 和 flex-wrap【案例】
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>08-flex-flow复合属性</title> <style> div { display: flex; width: 600px; height: 300px; background-color: pink; /* flex-direction: column; flex-wrap: wrap; */ /* 把设置主轴方向和是否换行(换列)简写 */ flex-flow: column wrap; } div span { width: 150px; height: 100px; background-color: gray; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> <span>4</span> <span>5</span> </div> </body> </html> 四、flex布局子项常见属性 flex 子项目占的份数align-self 控制子项自己在侧轴的排列方式order 属性定义子项的排列顺序(前后顺序) 4.1 flex属性flex 属性定义子项目分配剩余空间,用 flex 来表示占多少份数。
.item { flex: <number>; /* default 0 */ }【案例】
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>09-flex子项flex份数</title> <style> section { display: flex; width: 60%; height: 150px; background-color: pink; margin: 0 auto; } section div:nth-child(1) { width: 100px; height: 150px; background-color: rgb(166, 255, 139); } section div:nth-child(2) { flex: 1; background-color: rgb(0, 0, 0); } section div:nth-child(3) { width: 100px; height: 150px; background-color: rgb(124, 185, 255); } /* --------------------------------- */ p { display: flex; width: 60%; height: 150px; background-color: pink; margin: 100px auto; } p span { flex: 1; } p span:nth-child(2) { flex: 2; background-color: gray; } </style> </head> <body> <section> <div></div> <div></div> <div></div> </section> <p> <span>1</span> <span>2</span> <span>3</span> </p> </body> </html> 4.2 align-self控制子项自己在侧轴上的排列方式align-self 属性允许单个项目有与其他项目不一样的对齐方式,可覆盖 align-items 属性。
默认值 auto,表示继承父元素 align-items 属性,如果没有父元素,则等同于 stretch。
span:nth-child(2) { /* 设置自己在侧轴上的排列方式 */ align-self: flex-end; } 4.3 order属性定义项目的排列顺序数值越小,排列越靠前,默认为 0。
注意:和 z-index 不一样。
.item { order: <number>; }【案例】
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>10-align-self和order</title> <style> div { display: flex; width: 80%; height: 300px; background-color: pink; /* 让三个子盒子沿着侧轴底侧对齐 */ /* align-items: flex-end; */ /* 我们想只让3号盒子下来底侧 */ } div span { width: 150px; height: 100px; background-color: gray; margin-right: 5px; } div span:nth-child(2) { /* 排列顺序 */ /* 默认是0,-1比0小所以在前面 */ order: -1; } div span:nth-child(3) { /* 单独设置 */ align-self: flex-end; } </style> </head> <body> <div> <span>1</span> <span>2</span> <span>3</span> </div> </body> </html> 五、携程网首页案例制作【案例:携程网移动端首页】
访问地址:https://m.ctrip.com/
(1)技术选型
方案:我们采取单独制作移动页面方案
技术:布局采取 flex 布局
(2)搭建相关文件夹结构
(3)设置视口标签以及引入初始化样式
<meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0"> <link rel="stylesheet" href="css/normalize.css"> <link rel="stylesheet" href="css/index.css">(4)常用初始化样式
body { max-width: 540px; min-width: 320px; margin: 0 auto; font: normal 14px/1.5 Tahoma, "Lucida Grande", Verdana, "Microsoft Yahei", STXihei, hei; color: #000; background: #f2f2f2; overflow-x: hidden; -webkit-tap-highlight-color: transparent; }(5)常见模块命名
(6)常见 flex 布局思路
(7)背景线性渐变
语法:
background: linear-gradient(起始方向, 颜色1, 颜色2, ...); background: -webkit-linear-gradient(left, red , blue); background: -webkit-linear-gradient(left top, red , blue); 背景渐变必须添加浏览器私有前缀起始方向可以是:方位名词 或 度数,如果省略默认就是 top【案例】
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>11-背景线性渐变</title> <style> div { width: 600px; height: 200px; /* 背景渐变必须添加浏览器私有前缀 */ /* 由于此处是移动端,所以我们写 webkit 就够了 */ background: -webkit-linear-gradient(left, red, blue); /* background: -webkit-linear-gradient(red, blue); */ /* background: -webkit-linear-gradient(top left, red, blue); */ } </style> </head> <body> <div></div> </body> </html> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>11-背景线性渐变</title> <style> div { width: 600px; height: 200px; /* 背景渐变必须添加浏览器私有前缀 */ /* background: -webkit-linear-gradient(left, red, blue); */ background: -webkit-linear-gradient(red, blue); /* background: -webkit-linear-gradient(top left, red, blue); */ } </style> </head> <body> <div></div> </body> </html> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>11-背景线性渐变</title> <style> div { width: 600px; height: 200px; /* 背景渐变必须添加浏览器私有前缀 */ /* background: -webkit-linear-gradient(left, red, blue); */ /* background: -webkit-linear-gradient(red, blue); */ background: -webkit-linear-gradient(top left, red, blue); } </style> </head> <body> <div></div> </body> </html>【完整代码】
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <link rel="stylesheet" href="css/normalize.css"> <link rel="stylesheet" href="css/index.css"> <title>携程在手,说走就走</title> </head> <body> <!-- 顶部搜索 --> <div class="search-index"> <div class="search">搜索:目的地/酒店/景点/航班号</div> <a href="#" class="user">我 的</a> </div> <!-- 焦点图模块 --> <div class="focus"> <img src="upload/focus.jpg" alt=""> </div> <!-- 局部导航栏 --> <ul class="local-nav"> <li> <a href="#" title="景点·玩乐"> <span class="local-nav-icon-icon1"></span> <span>景点·玩乐</span> </a> </li> <li> <a href="#" title="景点·玩乐"> <span class="local-nav-icon-icon2"></span> <span>景点·玩乐</span> </a> </li> <li> <a href="#" title="景点·玩乐"> <span class="local-nav-icon-icon3"></span> <span>景点·玩乐</span> </a> </li> <li> <a href="#" title="景点·玩乐"> <span class="local-nav-icon-icon4"></span> <span>景点·玩乐</span> </a> </li> <li> <a href="#" title="景点·玩乐"> <span class="local-nav-icon-icon5"></span> <span>景点·玩乐</span> </a> </li> </ul> <!-- 主导航栏 --> <nav> <div class="nav-common"> <div class="nav-items"> <a href="#">海外酒店</a> </div> <div class="nav-items"> <a href="#">海外酒店</a> <a href="#">特价酒店</a> </div> <div class="nav-items"> <a href="#">海外酒店</a> <a href="#">特价酒店</a> </div> </div> <div class="nav-common"> <div class="nav-items"> <a href="#">海外酒店</a> </div> <div class="nav-items"> <a href="#">海外酒店</a> <a href="#">特价酒店</a> </div> <div class="nav-items"> <a href="#">海外酒店</a> <a href="#">特价酒店</a> </div> </div> <div class="nav-common"> <div class="nav-items"> <a href="#">海外酒店</a> </div> <div class="nav-items"> <a href="#">海外酒店</a> <a href="#">特价酒店</a> </div> <div class="nav-items"> <a href="#">海外酒店</a> <a href="#">特价酒店</a> </div> </div> </nav> <!-- 侧导航栏 --> <ul class="subnav-entry"> <li> <a href="#"> <span class="subnav-entry-icon"></span> <span>电话费</span> </a> </li> <li> <a href="#"> <span class="subnav-entry-icon"></span> <span>电话费</span> </a> </li> <li> <a href="#"> <span class="subnav-entry-icon"></span> <span>电话费</span> </a> </li> <li> <a href="#"> <span class="subnav-entry-icon"></span> <span>电话费</span> </a> </li> <li> <a href="#"> <span class="subnav-entry-icon"></span> <span>电话费</span> </a> </li> <li> <a href="#"> <span class="subnav-entry-icon"></span> <span>电话费</span> </a> </li> <li> <a href="#"> <span class="subnav-entry-icon"></span> <span>电话费</span> </a> </li> <li> <a href="#"> <span class="subnav-entry-icon"></span> <span>电话费</span> </a> </li> <li> <a href="#"> <span class="subnav-entry-icon"></span> <span>电话费</span> </a> </li> <li> <a href="#"> <span class="subnav-entry-icon"></span> <span>电话费</span> </a> </li> </ul> <!-- 销售模块 --> <div class="sales-box"> <div class="sales-hd"> <h2>热门活动</h2> <a href="#" class="more">获取更多福利</a> </div> <div class="sales-bd"> <div class="row"> <a href="#"> <img src="upload/pic1.jpg" alt=""> </a> <a href="#"> <img src="upload/pic2.jpg" alt=""> </a> </div> <div class="row"> <a href="#"> <img src="upload/pic3.jpg" alt=""> </a> <a href="#"> <img src="upload/pic4.jpg" alt=""> </a> </div> <div class="row"> <a href="#"> <img src="upload/pic5.jpg" alt=""> </a> <a href="#"> <img src="upload/pic6.jpg" alt=""> </a> </div> </div> </div> </body> </html> body { max-width: 540px; min-width: 320px; margin: 0 auto; font: normal 14px/1.5 Tahoma, "Lucida Grande", Verdana, "Microsoft Yahei", STXihei, hei; color: #000; background: #f2f2f2; overflow-x: hidden; -webkit-tap-highlight-color: transparent; } ul { list-style: none; margin: 0; padding: 0; } a { text-decoration: none; color: #222; } div { box-sizing: border-box; } /* 搜索模块 */ .search-index { display: flex; /* 固定定位跟父级没有关系 它以屏幕为准 */ position: fixed; top: 0; left: 50%; /* 固定的盒子应该有宽度 */ -webkit-transform: translateX(-50%); transform: translateX(-50%); width: 100%; min-width: 320px; max-width: 540px; height: 44px; /* background-color: pink; */ background-color: #f6f6f6; border-top: 1px solid #ccc; border-bottom: 1px solid #ccc; } .search { position: relative; height: 26px; line-height: 24px; border: 1px solid #ccc; flex: 1; font-size: 12px; color: #666; margin: 7px 10px; padding-left: 25px; border-radius: 5px; box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2); } .search::before { content: ""; position: absolute; top: 5px; left: 5px; width: 15px; height: 15px; background: url(../images/sprite.png) no-repeat -59px -279px; background-size: 104px auto; } .user { width: 44px; height: 44px; /* background-color: purple; */ font-size: 12px; text-align: center; color: #2eaae0; } .user::before { content: ""; display: block; width: 23px; height: 23px; background: url(../images/sprite.png) no-repeat -59px -194px; background-size: 104px auto; margin: 4px auto -2px; } /* focus */ .focus { padding-top: 44px; } .focus img { width: 100%; } /* local-nav */ .local-nav { display: flex; height: 64px; margin: 3px 4px; background-color: #fff; border-radius: 8px; } .local-nav li { flex: 1; } .local-nav a { display: flex; flex-direction: column; /* 侧轴居中对齐 因为是单行 */ align-items: center; font-size: 12px; } .local-nav li [class^="local-nav-icon"] { width: 32px; height: 32px; background-color: pink; margin-top: 8px; background: url(../images/localnav_bg.png) no-repeat 0 0; background-size: 32px auto; } .local-nav li .local-nav-icon-icon2 { background-position: 0 -32px; } .local-nav li .local-nav-icon-icon3 { background-position: 0 -64px; } .local-nav li .local-nav-icon-icon4 { background-position: 0 -96px; } .local-nav li .local-nav-icon-icon5 { background-position: 0 -128px; } /* nav */ nav { overflow: hidden; border-radius: 8px; margin: 0 4px 3px; } .nav-common { display: flex; height: 88px; background-color: pink; } .nav-common:nth-child(2) { margin: 3px 0; } .nav-items { /* 不冲突的 */ flex: 1; display: flex; flex-direction: column; } .nav-items a { flex: 1; text-align: center; line-height: 44px; color: #fff; font-size: 14px; /* 文字阴影 */ text-shadow: 1px 1px rgba(0, 0, 0, 0.2); } .nav-items a:nth-child(1) { border-bottom: 1px solid #fff; } .nav-items:nth-child(1) a { border: 0; background: url(../images/hotel.png) no-repeat bottom center; background-size: 121px auto; } /* -n+2就是选择前面两个元素 */ .nav-items:nth-child(-n + 2) { border-right: 1px solid #fff; } .nav-common:nth-child(1) { background: -webkit-linear-gradient(left, #fa5a55, #fa994d); } .nav-common:nth-child(2) { background: -webkit-linear-gradient(left, #4b90ed, #53bced); } .nav-common:nth-child(3) { background: -webkit-linear-gradient(left, #34c2a9, #6cd559); } /* subnav-entry */ .subnav-entry { display: flex; border-radius: 8px; background-color: #fff; margin: 0 4px; flex-wrap: wrap; padding: 5px 0; } .subnav-entry li { /* 里面的子盒子可以写 % 相对于父级来说的 */ flex: 20%; } .subnav-entry a { display: flex; flex-direction: column; align-items: center; } .subnav-entry-icon { width: 28px; height: 28px; background-color: pink; margin-top: 4px; background: url(../images/subnav-bg.png) no-repeat; background-size: 28px auto; } /* sales-box */ .sales-box { border-top: 1px solid #bbb; background-color: #fff; margin: 4px; } .sales-hd { position: relative; height: 44px; border-bottom: 1px solid #ccc; } .sales-hd h2 { position: relative; text-indent: -999px; overflow: hidden; } .sales-hd h2::after { position: absolute; top: 5px; left: 8px; content: ""; width: 79px; height: 15px; background: url(../images/hot.png) no-repeat 0 -20px; background-size: 79px auto; } .more { position: absolute; right: 5px; top: 0px; background: -webkit-linear-gradient(left, #ff506c, #ff6bc6); border-radius: 15px; padding: 3px 20px 3px 10px; color: #fff; } .more::after { content: ""; position: absolute; top: 9px; right: 9px; width: 7px; height: 7px; border-top: 2px solid #fff; border-right: 2px solid #fff; transform: rotate(45deg); } .row { display: flex; } .row a { flex: 1; border-bottom: 1px solid #eee; } .row a:nth-child(1) { border-right: 1px solid #eee; } .row a img { width: 100%; }
1.本站遵循行业规范,任何转载的稿件都会明确标注作者和来源;2.本站的原创文章,会注明原创字样,如未注明都非原创,如有侵权请联系删除!;3.作者投稿可能会经我们编辑修改或补充;4.本站不提供任何储存功能只提供收集或者投稿人的网盘链接。 |
标签: #17 #移动Web开发之flex布局 #传统布局与flex布局12 #初体验二flex布局原理21 #常见父项属性32