CSS3盒子模型（FLex弹性布局）实例代码全公开

前言

CSS3中的盒子模型（Flex弹性布局），是目前最流行的布局方式，相比于传统的Position，FLoat，Table 布局，盒子模型可以用更少的代码，实现更好的效果（比如：各种居中、对齐等）。

本文将把盒子模型中的各种布局方式，全面展示出来，并且直接提供相关代码，供读者使用。

GitHub项目地址：github.com/jiangjiahen…

项目展示

1. 盒子容器

图片示例

代码示例

<template>
  <div class="container">
    <div class="demo-box demo1">
      <h1>flex-flow示例：</h1>
      <h2>flex-flow:column wrap-reverse;</h2>
      <ul class="box">
        <li>a</li>
        <li>b</li>
        <li>c</li>
      </ul>
    </div>
    <div class="demo-box demo2">
      <h1>flex-direction示例：</h1>
      <h2>flex-direction:row-reverse</h2>
      <ul class="box">
        <li>a</li>
        <li>b</li>
        <li>c</li>
      </ul>
    </div>
    <div class="demo-box demo3">
      <h1>flex-wrap示例：</h1>
      <h2>flex-wrap:wrap</h2>
      <ul class="box">
        <li>a</li>
        <li>b</li>
        <li>c</li>
      </ul>
    </div>
    <div class="demo-box demo4">
      <h1>align-content示例：</h1>
      <h2>align-content:space-around</h2>
      <ul class="box">
        <li>a</li>
        <li>b</li>
        <li>c</li>
        <li>d</li>
        <li>e</li>
        <li>f</li>
      </ul>
    </div>
    <div class="demo-box demo5">
      <h1>align-items示例：</h1>
      <h2>align-items:flex-start</h2>
      <ul class="box">
        <li>a</li>
        <li>b</li>
        <li>c</li>
      </ul>
    </div>
    <div class="demo-box demo6">
      <h1>justify-content示例：</h1>
      <h2>justify-content:space-between</h2>
      <ul class="box">
        <li>a</li>
        <li>b</li>
        <li>c</li>
      </ul>
    </div>
  </div>
</template>

<style lang="scss" scoped>
.container {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
}

.demo-box {
  width: 440px;
  margin-bottom: 10px;
  padding-bottom: 20px;
  border: 1px solid black;
}

h1 {
  font: bold 20px/1.5 georgia, simsun, sans-serif;
}
.box {
  display: -webkit-flex;
  display: flex;
  width: 220px;
  margin: 0 auto;
  padding: 10px;
  list-style: none;
  background-color: #eee;
}
.box li {
  width: 100px;
  height: 100px;
  border: 1px solid #aaa;
  text-align: center;
}

.demo1 {
  .box {
    height: 220px;
    -webkit-flex-flow: column wrap-reverse;
    flex-flow: column wrap-reverse;
  }
}

.demo2 {
  .box {
    -webkit-flex-direction: row-reverse;
    flex-direction: row-reverse;
  }
}

.demo3 {
  .box {
    -webkit-flex-wrap: wrap;
    flex-wrap: wrap;
  }
}

.demo4 {
  .box {
    -webkit-flex-wrap: wrap;
    flex-wrap: wrap;
    width: 200px;
    height: 200px;
    border-radius: 5px;
    list-style: none;
    background-color: #eee;
    -webkit-align-content: space-around;
    align-content: space-around;
  }

  .box li {
    margin: 5px;
    padding: 10px;
    border-radius: 5px;
    background: #aaa;
    text-align: center;
    width: 10px;
    height: 10px;
  }
}

.demo5 {
  .box {
    width: 200px;
    height: 100px;
    border-radius: 5px;
    list-style: none;
    background-color: #eee;
    -webkit-align-items: flex-start;
    align-items: flex-start;
  }

  .box li {
    margin: 5px;
    padding: 10px;
    border-radius: 5px;
    background: #aaa;
    text-align: center;
    width: 10px;
    height: 10px;
  }
}

.demo6 {
  .box {
    -webkit-justify-content: space-between;
    justify-content: space-between;
  }

  .box li {
    margin: 5px;
    padding: 10px;
    border-radius: 5px;
    background: #aaa;
    text-align: center;
    width: 10px;
    height: 10px;
  }
}
</style>

2. 盒子项目

图片示例

代码示例

<template>
  <div class="container">
    <div class="demo-box demo1">
      <h1>flex示例：</h1>
      <ul class="box">
        <li>flex:1 1 400px;</li>
        <li>flex:1 2 400px;</li>
        <li>flex:1 2 400px;</li>
      </ul>
    </div>
    <div class="demo-box demo2">
      <h1>flex-grow示例：</h1>
      <ul class="box">
        <li>a</li>
        <li>b</li>
        <li>c</li>
        <li>d</li>
        <li>e</li>
      </ul>
    </div>
    <div class="demo-box demo3">
      <h1>flex-shrink示例：</h1>
      <ul class="box">
        <li>a</li>
        <li>b</li>
        <li>c</li>
      </ul>
    </div>
    <div class="demo-box demo4">
      <h1>flex-basis示例：</h1>
      <ul class="box">
        <li>a</li>
        <li>b</li>
        <li>c</li>
        <li>d</li>
        <li>e</li>
        <li>f</li>
      </ul>
    </div>
    <div class="demo-box demo5">
      <h1>align-self示例：</h1>
      <ul class="box">
        <li>a</li>
        <li>b</li>
        <li>c</li>
        <li>d</li>
        <li>e</li>
        <li>f</li>
        <li>g</li>
        <li>h</li>
        <li>i</li>
      </ul>
    </div>
    <div class="demo-box demo6">
      <h1>order示例：</h1>
      <ul class="box">
        <li>a</li>
        <li>b</li>
        <li>c</li>
      </ul>
    </div>
  </div>
</template>

<style lang="scss" scoped>
.container {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
}

.demo-box {
  width: 440px;
  margin-bottom: 10px;
  padding-bottom: 20px;
  border: 1px solid black;
}

h1 {
  font: bold 20px/1.5 georgia, simsun, sans-serif;
}

.box {
  display: -webkit-flex;
  display: flex;
  width: 400px;
  height: 100px;
  margin: 10px auto;
  padding: 0;
  border-radius: 5px;
  list-style: none;
  background-color: #eee;
  li {
    background: #aaa;
    text-align: center;
  }
}
.box li:nth-child(1) {
  background: #999;
}
.box li:nth-child(2) {
  background: #aaa;
}
.box li:nth-child(3) {
  background: #ccc;
}

.demo1 {
  .box {
    li:nth-child(1) {
      -webkit-flex: 1 1 400px;
      flex: 1 1 400px;
    }
    li:nth-child(2) {
      -webkit-flex: 1 2 400px;
      flex: 1 2 400px;
    }
    li:nth-child(3) {
      -webkit-flex: 1 2 400px;
      flex: 1 2 400px;
    }
  }
}

.demo2 {
  .box {
    li:nth-child(2) {
      -webkit-flex-grow: 1;
      flex-grow: 1;
    }
    li:nth-child(3) {
      -webkit-flex-grow: 2;
      flex-grow: 2;
    }
  }
}

.demo3 {
  .box {
    li {
      width: 200px;
    }
    li:nth-child(1) {
      background: #888;
    }
    li:nth-child(2) {
      background: #ccc;
    }
    li:nth-child(3) {
      -webkit-flex-shrink: 3;
      flex-shrink: 3;
      background: #aaa;
    }
  }
}

.demo4 {
  .box {
    li {
      width: 100px;
      height: 100px;
      border: 1px solid #aaa;
      text-align: center;
    }
    li:nth-child(3) {
      -webkit-flex-basis: 600px;
      flex-basis: 600px;
    }
  }
}

.demo5 {
  .box {
    display: -webkit-flex;
    display: flex;
    height: 100px;
    margin: 0;
    padding: 10px;
    border-radius: 5px;
    list-style: none;
    background-color: #eee;
  }
  .box li {
    margin: 5px;
    padding: 10px;
    border-radius: 5px;
    background: #aaa;
    text-align: center;
  }
  .box li:nth-child(1) {
    -webkit-align-self: flex-end;
    align-self: flex-end;
  }
  .box li:nth-child(2) {
    -webkit-align-self: center;
    align-self: center;
  }
  .box li:nth-child(3) {
    -webkit-align-self: flex-start;
    align-self: flex-start;
  }
  .box li:nth-child(4) {
    -webkit-align-self: baseline;
    align-self: baseline;
    padding: 20px 10px;
  }
  .box li:nth-child(5) {
    -webkit-align-self: baseline;
    align-self: baseline;
  }
  .box li:nth-child(6) {
    -webkit-align-self: stretch;
    align-self: stretch;
  }
  .box li:nth-child(7) {
    -webkit-align-self: auto;
    align-self: auto;
  }
}

.demo6 {
  .box {
    li {
      width: 100px;
      height: 100px;
      border: 1px solid #aaa;
      text-align: center;
    }
    li:nth-child(3) {
      -webkit-order: -1;
      order: -1;
    }
  }
}
</style>

3. 骰子的布局

图片示例

代码示例

<template>
  <div>
    <h1>骰子的布局</h1>
    <div class="container">
      <div class="demo1 dice">
        <span class="dice-point"></span>
      </div>
      <div class="demo2 dice">
        <span class="dice-point"></span>
        <span class="dice-point"></span>
      </div>
      <div class="demo3 dice">
        <span class="dice-point"></span>
        <span class="dice-point"></span>
        <span class="dice-point"></span>
      </div>
      <div class="demo4 dice">
        <div class="row">
          <span class="dice-point"></span>
          <span class="dice-point"></span>
        </div>
        <div class="row">
          <span class="dice-point"></span>
          <span class="dice-point"></span>
        </div>
      </div>
      <div class="demo5 dice">
        <div class="row">
          <span class="dice-point"></span>
          <span class="dice-point"></span>
        </div>
        <div class="row">
          <span class="dice-point"></span>
        </div>
        <div class="row">
          <span class="dice-point"></span>
          <span class="dice-point"></span>
        </div>
      </div>
      <div class="demo6 dice">
        <span class="dice-point"></span>
        <span class="dice-point"></span>
        <span class="dice-point"></span>
        <span class="dice-point"></span>
        <span class="dice-point"></span>
        <span class="dice-point"></span>
      </div>
    </div>
  </div>
</template>

<style lang="scss" scoped>
h1 {
  font-weight: bolder;
  text-align: center;
}
.container {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-around;
  margin-top: 100px;
}

.dice{
    width: 100px;
    height:100px;
    border-radius: 10px;
    background-color: #000;
    display: flex;
}

.dice-point{
    width: 22px;
    height: 22px;
    border-radius: 22px;
    margin:5px;
    background-color: #fff;
}

.demo1{
    justify-content: center;
    align-items: center;
}

.demo2{
    justify-content: space-between;
    align-items: center;
}

.demo3{
    .dice-point:nth-child(2){
        align-self: center;
    }
    .dice-point:nth-child(3){
        align-self: flex-end;
    }
}

.demo4, .demo5{
    flex-wrap: wrap;
}

.demo4 .row, .demo5 .row{
    flex-basis: 100%;
    display: flex;
    justify-content: space-between;
}

.demo4 .row:nth-child(2){
  align-items: flex-end;
}

.demo5 .row:nth-child(2){
  justify-content: center;
}

.demo6{
    flex-flow: column wrap;
    justify-content: space-between;
    align-content: space-between;
}
</style>

4. 网格的布局

图片示例

代码示例

<template>
  <div class>
    <h1>网格的布局</h1>
    <div class="container">
      <div class="Grid">
        <div class="Grid-cell u-full">full</div>
      </div>
      <div class="Grid">
        <div class="Grid-cell u-1of2">1of2</div>
        <div class="Grid-cell u-1of2">1of2</div>
      </div>
      <div class="Grid">
        <div class="Grid-cell u-1of3">1of3</div>
        <div class="Grid-cell u-1of3">1of3</div>
        <div class="Grid-cell u-1of3">1of3</div>
      </div>
      <div class="Grid">
        <div class="Grid-cell u-1of4">1of4</div>
        <div class="Grid-cell u-1of4">1of4</div>
        <div class="Grid-cell u-1of4">1of4</div>
        <div class="Grid-cell u-1of4">1of4</div>
      </div>
    </div>
  </div>
</template>

<style lang="scss" scoped>
.container {
  background-color: #fff;
  border: 4px solid lightgrey;
  border-radius: 10px;
  width: 80%;
  margin: 2% auto;
  position: relative;
}

.Grid {
  display: flex;
}

.Grid-cell {
  flex: 1;
  background-color: lightgrey;
  height: 50px;
  line-height: 50px;
  margin: 10px;
  font-size: 18px;
  font-weight: bolder;
  color:#fff;
}

.Grid-cell.u-full {
  flex: 0 0 98.3333%;
}

.Grid-cell.u-1of2 {
  flex: 0 0 48.3333%;
}

.Grid-cell.u-1of3 {
  flex: 0 0 31.6666%;
}

.Grid-cell.u-1of4 {
  flex: 0 0 23.3333%;
}
</style>

5. 圣杯的布局

图片示例

代码示例

<template>
  <div class>
    <h1>圣杯的布局</h1>
    <div class="container">
      <div class="HolyGrail">
        <div class="Header">#header</div>
        <div class="HolyGrail-body">
          <div class="HolyGrail-content">#center</div>
          <div class="HolyGrail-nav">#left</div>
          <div class="HolyGrail-ads">#right</div>
        </div>
        <div class="Footer">#footer</div>
      </div>
    </div>
  </div>
</template>

<style lang="scss" scoped>
.container {
  background-color: #fff;
  border: 4px solid lightgrey;
  border-radius: 10px;
  width: 80%;
  margin: 2% auto;
  position: relative;
}

.HolyGrail {
  display: flex;
  min-height: 100vh;
  flex-direction: column;
}

.Header,
.Footer {
  flex: 1;
  height: 100px;
  background-color: grey;
  color: #fff;
  line-height: 100px;
}

.HolyGrail-body {
  display: flex;
  flex: 1;
}

.HolyGrail-content {
  background-color: lightgrey;
  height: 600px;
  line-height: 600px;
  color: #fff;
  flex: 1;
}

.HolyGrail-nav,
.HolyGrail-ads {
  background-color: skyblue;
  height: 600px;
  line-height: 600px;
  color: #fff;
  flex: 0 0 12em;
}

.HolyGrail-nav {
  background-color: orange;
  order: -1;
}

@media (max-width: 768px) {
  .HolyGrail-body {
    flex-direction: column;
    flex: 1;
  }
  .HolyGrail-nav,
  .HolyGrail-ads,
  .HolyGrail-content {
    flex: auto;
  }
}
</style>

6. 输入框的布局

图片示例

代码示例

<template>
  <div class>
    <h1>输入框的布局</h1>
    <div class="container">
      <div class="InputAddOn">
        <span class="InputAddOn-item">
          <i class="el-icon-search"></i>
        </span>
        <input class="InputAddOn-field" />
        <button class="InputAddOn-item">Go</button>
      </div>
    </div>
  </div>
</template>

<style lang="scss" scoped>
.container {
  border-radius: 10px;
  width: 80%;
  margin: 0 auto;
  position: relative;
  height: 200px;
  display: flex;
  justify-content: center;
}

.InputAddOn {
  width: 400px;
  height: 30px;
  display: flex;
}

.InputAddOn-field {
  flex: 1;
}

.InputAddOn-item:first-child {
  background-color: lightgrey;
}

.InputAddOn-item {
  width: 30px;
  line-height: 30px;
  text-align: center;
  // border: 1px solid grey;
}
</style>

7. 悬挂式布局

图片示例

代码示例

<template>
  <div class>
    <h1>悬挂式布局</h1>
    <div class="Media">
        <img class="Media-figure" src="../../assets/logo.png" alt="logo" />
        <p class="Media-body">
          <span>Vue.js 是什么</span>
          Vue (读音 /vjuː/，类似于 view) 是一套用于构建用户界面的渐进式框架。与其它大型框架不同的是，Vue 被设计为可以自底向上逐层应用。Vue 的核心库只关注视图层，不仅易于上手，还便于与第三方库或既有项目整合。另一方面，当与现代化的工具链以及各种支持类库结合使用时，Vue 也完全能够为复杂的单页应用提供驱动。
          如果你想在深入学习 Vue 之前对它有更多了解，我们制作了一个视频，带您了解其核心概念和一个示例工程。
          如果你已经是有经验的前端开发者，想知道 Vue 与其它库/框架有哪些区别，请查看对比其它框架。
        </p>
      </div>
  </div>
</template>

<style lang="scss" scoped>

.Media {
  display: flex;
  align-items: flex-start;
  width: 50%;
  margin: 1% auto;
  background-color:#f0f0f0;
  padding: 1%;
}

.Media-figure {
  margin-right: 1em;
  width: 100px;
}

.Media-body {
  flex: 1;
  text-align: left;
  span{
    display: block;
    font-weight: bolder;
  }
}
</style>

8. 固定的底栏

图片示例

代码示例

<template>
  <div class>
    <h1>固定的底栏</h1>
    <div class="container">
      <div class="Site">
        <header>#header</header>
        <main class="Site-content">#content</main>
        <footer>#footer</footer>
      </div>
    </div>
  </div>
</template>

<style lang="scss" scoped>
.container {
  background-color: #fff;
  border: 4px solid lightgrey;
  border-radius: 10px;
  width: 80%;
  margin: 2% auto;
  position: relative;
}

.Site {
  display: flex;
  min-height: 100vh;
  flex-direction: column;
}

.Site-content {
  flex: 1;
  height: 400px;
  line-height: 400px;
}

header,
footer {
  height: 100px;
  background-color: grey;
  color: #fff;
  line-height: 100px;
}
</style>

9. 流式布局

图片示例

代码示例

<template>
  <div class>
    <h1>流式布局</h1>
    <div class="container">
      <div class="parent">
        <div class="child" v-for="(i,index) in 10" :key="index">{{i}}</div>
      </div>
    </div>
  </div>
</template>

<style lang="scss" scoped>
.container {
  background-color: #fff;
  border: 4px solid lightgrey;
  border-radius: 10px;
  width: 40%;
  margin: 2% auto;
  position: relative;
}

.parent {
  width: 200px;
  height: 150px;
  margin: 10% auto;
  background-color: black;
  display: flex;
  flex-flow: row wrap;
  align-content: flex-start;
}

.child {
  box-sizing: border-box;
  height: 50px;
  line-height: 50px;
  flex: 0 0 25%;
  background-color: white;
  border: 1px solid red;
}
</style>