vue3封装放大镜组件的实例代码

OStack程序员社区-中国程序员成长平台 › 门户 › 编程› JavaScript›JavaScript编程经验

原作者: [db:作者] 来自: [db:来源] 收藏邀请

组件基础结构

结尾有完整代码可直接复制使用

目的：封装图片预览组件，实现鼠标悬停切换效果

落地代码：

<template>
  <div class="goods-image">
    <div class="middle">
      <img :src="images[currIndex]" alt="">
    </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 { ref } from 'vue'
export default {
  name: 'GoodsImage',
  props: {
    images: {
      type: Array,
      default: () => []
    }
  },
  setup (props) {
    const currIndex = ref(0)
    return { currIndex }
  }
}
</script>
<style scoped lang="less">
.goods-image {
  width: 480px;
  height: 400px;
  position: relative;
  display: flex;
  .middle {
    width: 400px;
    height: 400px;
    background: #f5f5f5;
  }
  .small {
    width: 80px;
    li {
      width: 68px;
      height: 68px;
      margin-left: 12px;
      margin-bottom: 15px;
      cursor: pointer;
      &:hover,&.active {
        border: 2px solid @xtxColor;
      }
    }
  }
}
</style>

图片放大镜

目的：实现图片放大镜功能

步骤：

首先准备大图容器和遮罩容器
然后使用@vueuse/core的useMouseInElement方法获取基于元素的偏移量
计算出遮罩容器定位与大容器背景定位暴露出数据给模板使用

落地代码：

<template>
  <div class="goods-image">
+     // 实现右侧大图布局效果（背景图放大4倍）
+    <div class="large" :style="[{backgroundImage:`url(${images[currIndex]})`}]"></div>
    <div class="middle">
      <img :src="images[currIndex]" alt="">
+      // 准备待移动的遮罩容器
+     <div class="layer"></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 { ref } from 'vue'
export default {
  name: 'GoodsImage',
  props: {
    images: {
      type: Array,
      default: () => []
    }
  },
  setup (props) {
    const currIndex = ref(0)
    return { currIndex }
  }
}
</script>
<style scoped lang="less">
.goods-image {
  width: 480px;
  height: 400px;
  position: relative;
  display: flex;
+  z-index: 500;
+    // 右侧大图样式
+  .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;
+    // 遮罩样式
+    .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>

安装vueuse

npm i @vueuse/[email protected]

目前5.3.0版本相对稳定

vueuse提供的监听进入指定范围方法的基本使用

import { useMouseInElement } from '@vueuse/core'
const { elementX, elementY, isOutside } = useMouseInElement(target)

方法的参数target表示被监听的DOM对象；返回值elementX, elementY表示被监听的DOM的左上角的位置信息left和top；isOutside表示是否在DOM的范围内，true表示在范围之外。false表示范围内。

功能实现

<div v-if="isShow" class="large" :style="[{ backgroundImage: `url(${images[currIndex]})` }, bgPosition]"></div>
<div class="middle" ref="target">
   <img :src="images[currIndex]" alt="" />
   <div class="layer" v-if="isShow" :style="[position]"></div>
</div>

setup () {
// 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)
// 定义遮罩的坐标
const position = reactive({
      left: 0,
      top: 0
})
// 右侧预览大图的坐标
const bgPosition = reactive({
      backgroundPositionX: 0,
      backgroundPositionY: 0
})

return { position, bgPosition, target, isShow }
}

const { elementX, elementY, isOutside } = useMouseInElement(target)
  // 基于侦听器侦听值的变化
  watch([elementX, elementY, isOutside], () => {
    // 通过标志位控制显示和隐藏
    isShow.value = !isOutside.value
    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) {
      position.top = 0
    } else if (elementY.value > 300) {
      position.top = 200
    } else {
      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'
  })

完整代码

<template>
  <div class="goods-image">
    <div v-if="isShow" class="large" :style="[{ backgroundImage: `url(${images[currIndex]})` }, bgPosition]"></div>
    <div class="middle" ref="target">
      <img :src="images[currIndex]" alt="" />
      <div class="layer" v-if="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 { ref, watch, reactive } from 'vue'
import { useMouseInElement } from '@vueuse/core'
export default {
  name: 'GoodsImage',
  props: {
    images: {
      type: Array,
      default: () => []
    }
  },
  setup (props) {
    const currIndex = ref(0)
    const target = ref(null)
    const isShow = ref(false)
    const position = reactive({
      left: 0,
      top: 0
    })
    const bgPosition = reactive({
      backgroundPositionX: 0,
      backgroundPositionY: 0
    })
    const { elementX, elementY, isOutside } = useMouseInElement(target)
    watch([elementX, elementY, isOutside], () => {
      isShow.value = !isOutside.value
      if (isOutside.value) return
      if (elementX.value <= 100) {
        position.left = 0
      } else if (elementX.value >= 300) {
        position.left = 200
      } else {
        position.left = elementX.value - 100
      }
      if (elementY.value <= 100) {
        position.top = 0
      } else if (elementY.value >= 300) {
        position.top = 200
      } else {
        position.top = elementY.value - 100
      }
      bgPosition.backgroundPositionX = -position.left * 2 + 'px'
      bgPosition.backgroundPositionY = -position.top * 2 + 'px'
      position.left += 'px'
      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;
    background: #f5f5f5;
     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>