[JavaScript知识库]vue3电商项目中的商品详情-图片预览组件

目的：完成商品图片预览功能和切换

分享一个vueuse的插件useMouseInElement
useMouseInElement的官方文档

// 监听DOM元素
target
绑定的DOM元素中鼠标的X和Y值
elementX , elementY
//鼠标是否在绑定的DOM元素中
isOutside fasle是在DOM元素中,true是不在DOM元素中

<template>
  <div ref="target">
    <h1>Hello world</h1>
  </div>
</template>

<script>
import { ref } from 'vue'
import { useMouseInElement } from '@vueuse/core'

export default {
  setup() {
    const target = ref(null)

    const {  elementX ,  elementY , isOutside } = useMouseInElement(target)

    return {  elementX ,  elementY, isOutside }
  }
}
</script>

想要达到的目的:

在这里插入图片描述在这里插入图片描述

接下来是整个组件的代码

images的数据是一个由图片地址组成的数据

<template>
  <div class="goods-image" >
    <div class="large" v-show="isShow" :style="[{backgroundImage:`url(${images[currIndex]})`},bgPosition]"></div>
    <div class="middle" ref="target">
      <img :src="images[currIndex]" alt="" />
      <div class="layer" v-show="isShow" :style="[position]"></div>
    </div>
    <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: 'GoodsImage',
  props: {
    images: {
      type: Array,
      default: () => []
    }
  },
  setup (props) {
    const currIndex = ref(0)
    // 被监听的区域
    const target = ref(null)
    // 控制遮罩层和预览图的显示和隐藏
    const isShow = ref(false)
    // 遮罩层位置坐标
    const position = reactive({
      left: 0,
      top: 0
    })
    // 右侧预览大图的坐标
    const bgPosition = reactive({
      backgroundPositionX: 0,
      backgroundPositionY: 0
    })
    const { elementX, elementY, isOutside } = useMouseInElement(target)

    watch([elementX, elementY, isOutside], () => {
      // console.log(elementX.value, elementY.value, isOutside.value)
      // 通过标志位控制显示和隐藏
      isShow.value = !isOutside.value
      // 如果鼠标在图片外面就不在计算
      if (isOutside.value) return
      // X方向坐标范围控制
      if (elementX.value < 100) {
      // 左侧
        position.left = 0
      } else if (elementX.value > 300) {
      // 右侧
        position.left = 200
      } else {
      // 中间
        position.left = elementX.value - 100
      }
      // Y方向坐标范围控制
      if (elementY.value < 100) {
      // 左侧
        position.top = 0
      } else if (elementY.value > 300) {
      // 右侧
        position.top = 200
      } else {
      // 中间
        position.top = elementY.value - 100
      }
      // 计算预览大图的移动的距离
      bgPosition.backgroundPositionX = -position.left * 2 + 'px'
      bgPosition.backgroundPositionY = -position.top * 2 + 'px'
      // 计算遮罩层的位置
      position.left = position.left + 'px'
      position.top = position.top + 'px'
    })
    return { currIndex, target, isShow, position, bgPosition }
  }
}
</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;
    position: relative;
    cursor: move;
    .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;
      &:hover,
      &.active {
        border: 2px solid @xtxColor;
      }
    }
  }
}
</style>