v-bind动态改变样式

news2024/9/17 9:01:49

通过v-bind切换样式，:class="{ active:true}"为true展示样式，false不展示。也可以由:style="{ width:percent + '%'}"动态控制宽度。
注意后面是JS对象，所以后面的值不可以包含-，比如background-color会解析出错，应该写成backgroundColor，后面的值要有一对''包裹。

class案例（无样式）

当我们点击某一项时，对应的背景色就会变红。
在这里插入图片描述

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
<style>
  .active {
    background-color: red;
  }
</style>

<body>
  <div id="app">
    <ul>
      <li v-for="(item,index) in list" :key="item.id" @click="clickIndex=index" :class="{ active: clickIndex=== index}">
        {{item.name}}
      </li>
    </ul>
  </div>

  <script>
    const app = new Vue({
      el: '#app',
      data: {
        clickIndex: -1,
        list: [
          { id: 1, name: '优惠秒杀' },
          { id: 2, name: '特价优惠' }
        ]
      }
    })
  </script>
</body>
</html>

class案例（有样式）

在这里插入图片描述

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

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    * {
      margin: 0;
      padding: 0;
    }

    ul {
      display: flex;
      border-bottom: 2px solid #e01222;
      padding: 0 10px;
    }

    li {
      width: 100px;
      height: 50px;
      line-height: 50px;
      list-style: none;
      text-align: center;
    }

    li a {
      display: block;
      text-decoration: none;
      font-weight: bold;
      color: #333333;
    }

    li a.active {
      background-color: #e01222;
      color: #fff;
    }
  </style>
</head>

<body>

  <div id="app">
    <ul>
      <li v-for="(item,index) in list" :key="item.id" @click="activeIndex=index">
        <a :class="{active: activeIndex === index}" href="#">{{item.name}}</a>
      </li>
    </ul>
  </div>
  <script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
  <script>
    const app = new Vue({
      el: '#app',
      data: {
        activeIndex: 0,
        list: [
          { id: 1, name: '京东秒杀' },
          { id: 2, name: '每日特价' },
          { id: 3, name: '品类秒杀' }
        ]

      }
    })
  </script>
</body>

</html>

style案例

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

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>

<body>
  <div id="app">
    <div :style="{ backgroundColor:'red', width:width+'px',height: width+'px'}"></div>
    <button @click="width='200'">200px</button>
    <button @click="width='300'">300px</button>
  </div>

  <script>
    const app = new Vue({
      el: "#app",
      data: {
        width: '100'
      }
    })
  </script>
</body>
</html>