如何利用vue3实现放大镜效果实例详解

npm install @vueuse/core@5.3.0

<template>
  <div class="goods-image">
    <!-- 预览大图 -->
    <div class="large" :style='[{backgroundImage: `url(${images[currIndex]})`}, bgPosition]' v-show='isShow'></div>
    <div class="middle" ref='target'>
      <!-- 左侧的大图 -->
      <img :src="images[currIndex]" alt="">
      <!-- 遮罩层 -->
      <div class="layer" :style='[position]' v-show='isShow'></div>
    </div>
    <ul class="small">
      <!-- 右侧的缩略图 -->
       <li v-for="(img,i) in images" :key="img" :class="{active:i===currIndex}">
        <img @mouseenter="currIndex=i" :src="img" alt="">
      </li>
    </ul>
  </div>
</template>
<script>
import { ref, watch, reactive } from 'vue'
import { useMouseInElement } from '@vueuse/core'

export default {
  name: 'EnlargeImages',
  props: {
    images: {
      type: Array,
      default: () => []
    }
  },
  setup (props) {
    const currIndex = ref(0)
    const target = ref(null)
    const isShow = ref(false)
    // 遮罩层的坐标
    const position = reactive({
      left: 0,
      top: 0
    })
    // 控制背景图的位置
    const bgPosition = reactive({
      backgroundPositionX: 0,
      backgroundPositionY: 0
    })
    const { elementX, elementY, isOutside } = useMouseInElement(target)
    // 侦听鼠标移动后信息
    watch([elementX, elementY, isOutside], () => {
      // 每次有值发生变化，就读取新的数据即可
      isShow.value = !isOutside.value
      // 鼠标在图片的区域之外，不需要计算坐标
      if (isOutside.value) return
      // 水平方向
      if (elementX.value < 100) {
        // 左边界
        position.left = 0
      } else if (elementX.value > 300) {
        // 右边界
        position.left = 200
      } else {
        // 中间的状态
        position.left = elementX.value - 100
      }
      // 垂直方向
      if (elementY.value < 100) {
        // 上边界
        position.top = 0
      } else if (elementY.value > 300) {
        // 下边界
        position.top = 200
      } else {
        // 中间的状态
        position.top = elementY.value - 100
      }
      // console.log(elementX.value, elementY.value, isOutside.value)
      // 计算预览大图背景的位置
      bgPosition.backgroundPositionX = -position.left * 2 + 'px'
      bgPosition.backgroundPositionY = -position.top * 2 + 'px'
      // 计算左侧遮罩层位置
      position.left += 'px'
      position.top += 'px'
    })
    return { currIndex, target, isShow, position, bgPosition }
  }
}
</script>
<style scoped lang="less">
.goods-image {
  box-sizing: border-box;
  width: 480px;
  height: 400px;
  position: relative;
  display: flex;
  z-index: 500;
   img {
        width: 100%;
        height: 100%;
    }
  .large {
    position: absolute;
    top: 0;
    left: 410px;
    width: 400px;
    height: 400px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    background-repeat: no-repeat;
    background-size: 800px 800px;
    background-color: #f8f8f8;
  }
  .middle {
    width: 400px;
    height: 400px;
    background: #f5f5f5;
    position: relative;
    cursor: move;
    .layer {
      width: 200px;
      height: 200px;
      background: rgba(0, 0, 0, 0.2);
      left: 0;
      top: 0;
      position: absolute;
    }
  }
  .small {
    margin: 0;
    padding: 0;
    width: 80px;
    li {
      width: 68px;
      height: 68px;
      margin: 10px;
      list-style: none;
      cursor: pointer;
      &:hover,
      &.active {
        border: 2px solid #27ba9b;
      }
    }
  }
}
</style>

import EnlargeImages from './enlarge-images.vue'

export default {
  install (app) {
    app.component(EnlargeImages.name, EnlargeImages)
  }
}

import { createApp } from 'vue'
import App from './App.vue'
import router from './router'
import store from './store'
// 自己封装的
import myUI from './components'

createApp(App).use(store).use(router).use(myUI).mount('#app')

<template>
  <div class="home-banner">
    <!-- 放大镜效果 -->
    <enlarge-images :images="images"/>
  </div>
</template>

<script>

export default {
  name: 'App',
  setup() {
    const images = [
      'https://code-1307161657.cos.ap-beijing.myqcloud.com/images%2Fcloud.jpeg',
      'https://code-1307161657.cos.ap-beijing.myqcloud.com/images%2Fground.jpeg',
      'https://code-1307161657.cos.ap-beijing.myqcloud.com/images%2Fnight.jpeg',
      'https://code-1307161657.cos.ap-beijing.myqcloud.com/images%2Fstreet.jpeg',
      'https://code-1307161657.cos.ap-beijing.myqcloud.com/images%2Fsun.jpeg'
    ]

    return { images }
  }
}
</script>

<style lang="less">
.home-banner {
  width: 1000px;
  margin: 50px auto;
}
</style>