vue3 实现放大镜

最近在做商城项目，需求有个详情的时候要用到放大镜，
如下图展示，默认中图是第一个（我们给定一个默认值下标0）划过小图的时候中图变化，划过中图的时候大图显示并会放大

直接上代码了
index数据布局，这里展示的多个布局。只是给你看看，

注意的是我们要用父子组件的话，在父组件调取接口进行赋值传递给子组件展示就行了。（注意的是为了得到展示效果，我们在获取数据的时候可以加判断，给一些默认数据，防止后端数据为空，页面空白的不美观）

index的数据处理

<script setup>
import { reactive, ref } from "vue";
import GoodsInfo from "./goodsInfo/index.vue";
import GoodsParam from "./goodsParam/index.vue";
import Thumbnail from "@/components/biz/thumbnail/index.vue";
import { getGoodsDetails } from "./service";
import { useRoute, useRouter } from "vue-router";

let GoodShopDetail = reactive({
  googsList: [],
  fileList: [], // 图片信息
  formData: {},
  defaultImage: [ // 默认图片信息
    {
      fileCode: null,
      fileName: null,
      fileSize: null,
      fileType: "IMG",
      imgSize: null,
      major: null,
      url: "https://t13.baidu.com/it/u=3936526289,2831462857&fm=224&app=112&size=h200&n=0&f=JPEG&fmt=auto?sec=1672506000&t=a54bc61cf3298f3ec14aa49f5e8d91bb",
    },
    {
      fileCode: null,
      fileName: null,
      fileSize: null,
      fileType: "IMG",
      imgSize: null,
      major: null,
      url: "https://t13.baidu.com/it/u=14146861,892696632&fm=224&app=112&size=h200&n=0&f=JPEG&fmt=auto?sec=1672506000&t=9a34b3639439123cb347a79044197f06",
    },
  ],
});

const route = useRoute();
const router = useRouter();
let spuId = ref("");
spuId.value = route.query.id;
// spuId.value = "449768365155823616";
console.log(spuId.value, "接收传递的id");
const getItemDetail = async () => {
  const res = await getGoodsDetails(spuId.value);
  console.log(res, "查询详情接口");
  GoodShopDetail.googsList = res.data?.itemProps;
  // console.log(GoodShopDetail.googsList, "右侧信息展示");
  GoodShopDetail.fileList = res.data?.spuImages
    ? res.data?.spuImages
    : GoodShopDetail.defaultImage;
  // console.log(GoodShopDetail.fileList, "左侧放大镜");
  GoodShopDetail.formData = res.data;
  GoodShopDetail.formData?.skuVOs.forEach((item) => {
    item.number = 0;
  });
};
onMounted(() => {
  getItemDetail();
});
</script>

这里是放大镜代码

<template id="GoodsImage">
  <div class="goods-image">
    <!-- 大图 -->
    <template v-if="images && images.length > 0">
      <div
        v-show="show"
        class="large"
        :style="[
          { backgroundImage: `url(${images[currIndex]['url']})` },
          largePosition,
        ]"
      ></div>
    </template>

    <!-- 中图 -->
    <div class="middle" ref="target" v-if="images && images.length > 0">
      <!-- <img :src="images[0]['url']" alt="" /> 只展示第一个-->
      <img :src="images[currIndex]['url']" alt="" />
      <!-- 遮罩色块 -->
      <div v-show="show" class="layer" :style="layerPosition"></div>
    </div>

    <!-- 小图 -->
    <ul class="small">
      <li
        v-for="(item, i) in images"
        :key="item"
        :class="{ active: currIndex === i }"
      >
        <img @mouseenter="currIndex = i" :src="item.url" alt="" />
      </li>
    </ul>
  </div>
</template>

<script setup>
import { useMouseInElement } from "@vueuse/core";
import { reactive, ref } from "vue";
const props = defineProps({
  images: {
    type: Array,
    default: () => [],
  },
});
console.log(props.images, "images没有数据就是默认的");
const currIndex = ref(0); // 默认展示第一个
// 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({
  top: 0,
  left: 0,
});
// 3. 大图的背景坐标(样式)
const largePosition = reactive({
  backgroundPositionX: 0,
  backgroundPositionY: 0,
});
// 4. 获取监听元素的实例对象, 使用useMouseInElement函数进行获取坐标
const target = ref(null);
const { elementX, elementY, isOutside } = useMouseInElement(target);

// 5. 监听元素坐标值的变化
watch([elementX, elementY, isOutside], () => {
  show.value = !isOutside.value;
  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;
  }

  layerPosition.left = position.X + "px";
  layerPosition.top = position.Y + "px";
  largePosition.backgroundPositionX = -2 * position.X + "px";
  largePosition.backgroundPositionY = -2 * position.Y + "px";
});
</script>

<style lang="less" scoped>
.goods-image {
  width: 480px;
  height: 480px;
  position: relative;
  display: flex;
  flex-direction: column;
  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;
    .layer {
      width: 200px;
      height: 200px;
      background: rgba(0, 0, 0, 0.2);
      left: 0;
      top: 0;
      position: absolute;
    }
    img {
      width: 100%;
      height: 100%;
    }
  }
  .small {
    display: flex;
    width: 100%;
    li {
      width: 68px;
      height: 68px;
      margin-left: 12px;
      margin-bottom: 15px;
      cursor: pointer;
      &:hover,
      &.active {
        border: 2px solid gray;
      }
      img {
        width: 100%;
        height: 100%;
      }
    }
  }
}
</style>
样式可以自己调节