详细代码:

HTML:

<template>
  <div class="mirror">
      <div class="wrap"  :style="{width:width+'px',height:width+'px'}" >
        <div ref="truth" :style="{width:'100%',height:'100%'}" @mousemove="move" @mouseenter="showMagnify" @mouseleave="hideMagnify">
        <div class="mask" ref="mask" v-show = "showMask" :style="{width:width/2+'px',height:width/2+'px',left:maskPosition.x+'px',top:maskPosition.y+'px'}"></div>
        <img :src="picList[picIndex]" draggable="false"/>
        </div>
        <div class="virtual" ref="virtual" v-if = "isShowVirtual" :style="{width:width+'px',height:width+'px'}" >
            <div class="big" ref = "bigPic" :style="{position:'absolute',width:2*width+'px',height:2*width+'px',backgroundSize:'100% 100%',backgroundImage:`url(${picList[picIndex]})`,left:percent.x, top:percent.y}" >
            </div>
        </div>

      </div>

      <ul class="picList" :style="{width:width+'px'}">
          <li v-for = "(item,index) in picList" :class="{now:index==picIndex}" :data-index="index" :key ="item" @mouseenter="changeIndex">
            <img :src ="item" />
          </li>
      </ul>
  </div>
</template>

JS:

    export default {
      props:['width','picList'],//宽度是用来给放大镜的
      data(){
        return {

          picIndex:0,
          isShowVirtual:false,
          showMask:false,
          maskPosition:{},
          percent:{},
        }
      },
      methods:{

        computedOffset(obj,prop){ //计算元素到body的绝对位置
        if(obj==document.body || obj.offsetParent == document.body){
          return parseInt(obj[prop])
        }
        return parseInt(obj[prop])+this.computedOffset(obj.offsetParent,prop)
    },
        changeIndex(e){
          this.picIndex = e.target.dataset.index
        },
        showMagnify(e){
          this.showMask=true;
          this.isShowVirtual = true;

        },
        hideMagnify(){
          this.isShowVirtual=false;
          this.showMask=false
        },


        computePosition(e){
            let x = e.pageX,y = e.pageY;
            let mask = this.$refs.mask;
            let truth = this.$refs.truth;
            let virtual = this.$refs.virtual;
            let bigPic = this.$refs.bigPic;
            x = x-this.computedOffset(truth,'offsetLeft') -mask.offsetWidth/2;
            y = y-this.computedOffset(truth,'offsetTop')- mask.offsetHeight/2;

          if(x<=0) {
              x=0
            }else if(x>truth.offsetWidth - mask.offsetWidth){
              x = truth.offsetWidth/2
            }

            if(y<=0){
              y=0;
            }
            else if(y>truth.offsetHeight - mask.offsetHeight){
              y = truth.offsetHeight/2
            }





            this.maskPosition = {
              x,y
            }

            //计算比例

            this.percent={
              x:-x/(truth.offsetWidth-mask.offsetWidth)*(bigPic.offsetWidth - virtual.offsetWidth)+'px',
              y:-y/(truth.offsetHeight-mask.offsetHeight)*(bigPic.offsetHeight - virtual.offsetHeight)+'px'
            }
        },
        move(e){

          this.computePosition(e)

        }
    }
    }

css:

<style lang="less" scoped>
.now{
  border-color: cyan !important;

}
  .mirror{
    width:100%;
    .wrap{
      user-select: none;
      margin-bottom: 20px;
      position: relative;
      background-color: #fff;
      border:1px solid gray;
      box-sizing:border-box;
          cursor: pointer;

        img{
          width:100%;
          height:100%;
        }
        .virtual{
          overflow:hidden;

          width:100%;
          height:100%;
          position:absolute;
          left:calc(100% + 10px);
          top:0;
          background-repeat:no-repeat
        }
        .mask{
          position: absolute;
          background-image: url('https://img-tmdetail.alicdn.com/tps/i4/T12pdtXaldXXXXXXXX-2-2.png');
          background-repeat:repeat;
          cursor: move;
        }
    }

    .picList{

      width:100%;
      display: flex;
      justify-content: space-between;
      flex-wrap:wrap;
      li{
        width:50px;
        height:50px;
        margin:5px;
        border:1px solid transparent;
        box-sizing: border-box;
        img{
          width:100%;
          height:100%
        }
      }
    }
    .picList:after{
      content:"";
      flex:auto;
    }
  }
</style>

可直接复制文件内容至项目使用，文件地址：https://blog-static.cnblogs.com/files/hhyf/mirror.vue.js

效果