flex项目上的三个属性 -

flex项目上的三个属性

<!DOCTYPE html>

<html lang="zh-CN">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>设置某一个项目在交叉轴上的对齐方式</title>
<style>
{
box-sizing: border-box;
}

:root {
font-size: 10px;
}
body {
font-size: 1.6rem;
}
### 转为flex弹性布局元素
```

.container {
display: flex;
height: 20rem;
border: 1px solid #000;

/ position: relative; /
}
.container > .item {
/ width: 5em; /
background-color: lightcyan;
border: 1px solid #000;
}

###例如设置第2个项目与其它项目的对齐方式不一样
.container > .item:nth-of-type(2) {
align-self: stretch;
align-self: flex-start;
align-self: flex-end;
align-self: center;
}
###flex项目支持定位定位父级
.container {
position: relative;
}
.container > .item:nth-of-type(2) {
position: absolute;
left: 3rem;
top: 3rem;
/ 通过定位,可以许多非常复杂,甚至匪夷所思的布局 */
}
```
</style>
</head>

<body>
<div class="container">
<div class="item">item1</div>
<div class="item">item2</div>
<div class="item">item3</div>
<div class="item">item4</div>
</div>
</body>
</html>

设置项目在主轴上的显示顺序

   * {
        box-sizing: border-box;
      }
      :root {
        font-size: 10px;
      }
      body {
        font-size: 1.6rem;
      }
      .container {
        /* 转为flex弹性布局元素 */
        display: flex;
        height: 20rem;
        border: 1px solid #000;
        position: relative;
      }
      .container > .item {
        flex: auto;
        background-color: lightcyan;
        border: 1px solid #000;
      }

显示顺序:默认按书写的源码顺序排列默认序号越小越靠前,越大越靠后

.container > .item:first-of-type {
        order: 1;
        order: 5;
        background-color: yellow;
      }
      .container > .item:nth-of-type(2) {
        order: 2;
        background-color: lightgreen;
      }
      .container > .item:nth-of-type(3) {
        order: 3;
        order: 0;
      }
      .container > .item:last-of-type {
        order: 4;
        /* 支持负值 */
        order: -1;
        background-color: #ccc;
      }

</style>

</head>

flex项目上的三个属性