[JavaScript知识库]【VUE实现放大镜组件代码】

二、实现代码

1.实现代码

代码如下（示例）：

<template>
  <div class="spec-preview">
    <img :src="imgObj.imgUrl" />
    <div class="event" @mousemove="handle"></div>
    <div class="big" >
      <img :src="imgObj.imgUrl" ref="big" />
    </div>
    <div class="mask" ref="mask"></div>
  </div>
</template>

<script>
  export default {
    name: "Zoom",
    props:['skuImageList'],
    data() {
      return {
        currIndex:0,
      };
    },
    computed:{
      imgObj(index){
        return this.skuImageList[this.currIndex]||[]
      }
    },
    methods: {
      //修改放大镜显示图片
      handle(event){
          let mask = this.$refs.mask;
          let big= this.$refs.big;
          //获取mask距离与边框的水平距离
          //用鼠标离边框的距离-mask的宽度的一半
          let left = event.offsetX - mask.offsetWidth/2;
          //获取mask距离与边框的垂直距离
          //用鼠标离边框的距离-mask的高度度的一半
          let top = event.offsetY - mask.offsetHeight/2;
          
          //限制区域
          //限制水平方向
          if(left<=0){left=0}
          if(left>=mask.offsetWidth){left=mask.offsetWidth}
          //限制垂直方向
          if(top<=0){top=0}
          if(top>=mask.offsetHeight){top=mask.offsetHeight}
          //修改样式
          mask.style.left = left+'px';
          mask.style.top = top+'px';
          //修改大图样式
          big.style.left = -2 *left+'px'
           big.style.top = -2 *top+'px'
      }
    },
    mounted() {
      //全局事件总线：获取兄弟组件传递过来的索引值
      this.$bus.$on('changImgIndex',(index)=>{
        //修改选择的索引值
          this.currIndex=index
      })
    },

  }
</script>

<style lang="less" >
  .spec-preview {
  position: relative;
  width: 400px;
  height: 400px;
  border: 1px solid #ccc;
}
.spec-preview img {
  width: 100%;
  height: 100%;
}
.spec-preview .event {
  width: 100%;
  height: 100%;
  position: absolute;
  top: 0;
  left: 0;
  z-index: 998;
}
.spec-preview .mask {
  width: 50%;
  height: 50%;
  background-color: rgba(0, 255, 0, 0.3);
  position: absolute;
  left: 0;
  top: 0;
  display: none;
}
.spec-preview .big {
  width: 100%;
  height: 100%;
  position: absolute;
  top: -1px;
  left: 100%;
  border: 1px solid #aaa;
  overflow: hidden;
  z-index: 998;
  display: none;
  background: white;
}
.spec-preview .big img {
  width: 200%;
  max-width: 200%;
  height: 200%;
  position: absolute;
  left: 0;
  top: 0;
}
.spec-preview .event:hover ~ .mask,
.spec-preview .event:hover ~ .big {
  display: block;
}

</style>