vue3使用useMouseInElement实现图片局部放大预览效果

Posted 2023-04-02 jjw_zyfx

1、首先要安装@vueuse/core

npm i @vueuse/core

2、实现过程如下：

<template>
  <div class="goods-image">
    <!-- 大图 -->
    <div v-show="show" class="large" :style="[backgroundImage:`url($images[currIndex])`,largePosition]"></div>
    <!-- 中图 -->
    <div class="middle" ref="target">
      <img :src="images[currIndex]" alt="">
      <!-- 遮罩色块 -->
      <div v-show="show" class="layer" :style="layerPosition"></div>
    </div>
    <!-- 小图 -->
    <ul class="small">
      <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  reactive, ref, watch  from 'vue'
import  useMouseInElement  from '@vueuse/core'
export default 
  name: 'HelloWorld',
  props: 
    images: 
      type: Array,
      default: () => ['https://yanxuan-item.nosdn.127.net/a6939f41c48fa9e9c8f7a7ed855351f1.jpg',
        'https://yanxuan-item.nosdn.127.net/0cdfd546f8675669b87716114ad5900a.jpg',
        'https://yanxuan-item.nosdn.127.net/240983ccc935146a4795e3990d30468d.jpg',
        'https://yanxuan-item.nosdn.127.net/d46e005025a5d3b73c4781d31b327558.jpg',
        'https://yanxuan-item.nosdn.127.net/330913911087b44b0d817dd78233165f.png',]
    
  ,
  setup (props) 
    // 当前预览图的索引
    const currIndex = ref(0)

    // 1. 是否显示遮罩和大图
    const show = ref(false)
    // 2. 遮罩的坐标(样式)
    const layerPosition = reactive(
      left: 0,
      top: 0
    )
    // 3. 大图背景定位(样式)
    const largePosition = reactive(
      backgroundPositionX: 0,
      backgroundPositionY: 0
    )
    // 4. 使用useMouseInElement得到基于元素左上角的坐标和是否离开元素数据
    const target = ref(null)
    const  elementX, elementY, isOutside  = useMouseInElement(target)
    watch([elementX, elementY, isOutside], () => 
      // 5. 根据得到数据设置样式数据和是否显示数据
      show.value = !isOutside.value
      // 计算坐标
      const position =  x: 0, y: 0 

      if (elementX.value < 100) position.x = 0
      else if (elementX.value > 300) position.x = 200
      else position.x = elementX.value - 100

      if (elementY.value < 100) position.y = 0
      else if (elementY.value > 300) position.y = 200
      else position.y = elementY.value - 100
      // 给样式赋值
      layerPosition.left = position.x + 'px'
      layerPosition.top = position.y + 'px'
      largePosition.backgroundPositionX = -2 * position.x + 'px'
      largePosition.backgroundPositionY = -2 * position.y + 'px'
    )

    return  currIndex, show, layerPosition, largePosition, target 
  

</script>
<style scoped lang="less">
.goods-image 
  width: 480px;
  height: 400px;
  position: relative;
  display: flex;
  z-index: 500;
  .large 
    position: absolute;
    top: 0;
    left: 412px;
    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;
    img
      width: 100%;
      height: 100%;
    
    //cursor: pointer;
    .layer 
      width: 200px;
      height: 200px;
      background: rgba(0,0,0,.2);
      left: 0;
      top: 0;
      position: absolute;
    
  
  .small 
    width: 80px;
    li 
      width: 68px;
      height: 68px;
      margin-left: 12px;
      margin-bottom: 15px;
      cursor: pointer;
      img
        width: 100%;
        height: 100%;
      
      &:hover,&.active 
        border: 2px solid #27BA9B;
      
    
  

</style>

3、使用：在其他的.vue文件中导入组件即可使用，例如：

import HelloWorld from "@/components/HelloWorld.vue";
<HelloWorld ></HelloWorld>

4、效果如下：

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今天带来的是@winter老师在第三届Vue.js开发者大会上分享的《使用Vue实现0代码交互》。

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