学习css 伪类:has

news2024/12/28 8:29:13

学习抖音： @渡一前端提薪课

首先我们看下:has(selector)是什么

匹配包含（相对于 selector 的 :scope）指定选择器的元素。可以认为 selector 的前面有一个看不见的 :scope 伪类。它的强大之处是，可以实现父选择器和前面兄弟选择器的功能。支持所有的 CSS 选择符。

我们举个例子：

css

  .box1:has(p) {
    color: red;
}
        
.box1:has(span) {
    color: blue;
}
.box1:has(a, div) {
    color: greenyellow;
}

html

<body>

    <div class="box1">
        <p>ppp</p>
    </div>
    <div class="box1">
        <span>span</span>
    </div>
    <div class="box1">
        <a>有p</a>
    </div>
    <div class="box1">
        <div>有div</div>
    </div>
</body>

结果，.box1:has(p) 就是包含 p 标签的.box1 元素。.box1:has(span)就是包含span的元素，.box1:has(a, div) 就是包换 a 和包含div的元素

进阶

知道这个原理后我们在进阶一下，看看子的伪类可不可以用。

css

.box1:has(.red:hover) {
    color: red;
}
.box1:has(.blue:hover) {
    color: blue;
}
.box1:has(.yellow:hover) {
    color: yellow;
}

html

<div class="box1">
    <div class="red">变红色</div>
    <div class="blue">变蓝色</div>
    <div class="yellow">变黄色</div>
</div>

结果：

基于这个特效我们做一个案例

案例

直接上代码

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>demo-2</title>

    <style>
        * {
            padding: 0;
            margin: 0;
        }
        
        .container {
            width: 400px;
            height: 400px;
            border: 2px solid #999;
            position: absolute;
            top: 100px;
            left: 50%;
            transform: translateX(-50%);
            display: grid;
            transition: 0.5s;
            grid-template-columns: 1fr 1fr 1fr;
            grid-template-rows: 1fr 1fr 1fr;
            gap: 5px
        }
        
        .item:nth-of-type(1) {
            background: red;
        }
        
        .item:nth-of-type(2) {
            background: rgb(255, 208, 0);
        }
        
        .item:nth-of-type(3) {
            background: rgb(0, 255, 0);
        }
        
        .item:nth-of-type(4) {
            background: rgb(166, 255, 0);
        }
        
        .item:nth-of-type(5) {
            background: rgb(170, 88, 224);
        }
        
        .item:nth-of-type(6) {
            background: rgba(0, 238, 255, 0.726);
        }
        
        .item:nth-of-type(7) {
            background: rgb(255, 115, 0);
        }
        
        .item:nth-of-type(8) {
            background: rgb(86, 75, 241);
        }
        
        .item:nth-of-type(9) {
            background: rgb(255, 0, 149);
        }
        
        .container:has(.item:nth-of-type(1):hover) {
            grid-template-columns: 2fr 1fr 1fr;
            grid-template-rows: 2fr 1fr 1fr;
        }
        
        .container:has(.item:nth-of-type(2):hover) {
            grid-template-columns: 1fr 2fr 1fr;
            grid-template-rows: 2fr 1fr 1fr;
        }
        
        .container:has(.item:nth-of-type(3):hover) {
            grid-template-columns: 1fr 1fr 2fr;
            grid-template-rows: 2fr 1fr 1fr;
        }
        
        .container:has(.item:nth-of-type(4):hover) {
            grid-template-columns: 2fr 1fr 1fr;
            grid-template-rows: 1fr 2fr 1fr;
        }
        
        .container:has(.item:nth-of-type(5):hover) {
            grid-template-columns: 1fr 2fr 1fr;
            grid-template-rows: 1fr 2fr 1fr;
        }
        
        .container:has(.item:nth-of-type(6):hover) {
            grid-template-columns: 1fr 1fr 2fr;
            grid-template-rows: 1fr 2fr 1fr;
        }
        
        .container:has(.item:nth-of-type(7):hover) {
            grid-template-columns: 2fr 1fr 1fr;
            grid-template-rows: 1fr 1fr 2fr;
        }
        
        .container:has(.item:nth-of-type(8):hover) {
            grid-template-columns: 1fr 2fr 1fr;
            grid-template-rows: 1fr 1fr 2fr;
        }
        
        .container:has(.item:nth-of-type(9):hover) {
            grid-template-columns: 1fr 1fr 2fr;
            grid-template-rows: 1fr 1fr 2fr;
        }
    </style>
</head>

<body>
    <div class="container">
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
    </div>
</body>
<script>
</script>

</html>

效果：