vue+element 上传图片时获取索引值index

由于element上传图片的时候调用的 before-upload 方法不能传参数，只能传文件，如下图所示：

但是我们想要获得本次上传图片的索引值，没办法再这个方法里面传参数，如下图所示：

我们想要获取当前索引值，就需要再包裹上传图片组件的div上面添加点击事件，点击获取当前索引值。代码如下:

//html部分
<div class="relevanceGoods-box" v-if="clerkForm.relevanceGoods.length > 0">
  <div
    v-for="(item, index) in clerkForm.relevanceGoods"
    :key="index"
    class="relevanceGoods-item"
  >
    <div class="uploadImg_box" @click="getIndex(index)">
      <div class="pic_box" v-if="item.activeBanner.length > 0">
        <img
          v-loading="loadingUpload"
          :src="item.activeBanner"
          style="width:80px; height:80px; display:block;"
          alt
        />
        <div class="delete_box">
          <el-button
            type="success"
            icon="el-icon-zoom-in"
            @click="zoomImg(item.activeBanner)"
            circle
          ></el-button>
          <el-button type="danger" icon="el-icon-delete" @click="deleteImg(index)" circle></el-button>
        </div>
      </div>
      <el-upload
        v-if="clerkForm.relevanceGoods.length < 4"
        class="upload_box"
        action="#"
        list-type="picture-card"
        :before-upload="beforeImgUpload"
      >
        <i class="el-icon-plus" v-loading="loadingUpload"></i>
      </el-upload>
    </div>
    <div class="relevanceGoods-text">
      <span>{{item.goodsSkuCode}}</span>
      <span style="margin-left:20px;">{{item.goodsAndSpec}}</span>
      <span style="margin-left:50px;">￥{{item.actAmount}}</span>
      <span style="margin-left:20px;">{{item.stockNum}}件</span>
    </div>
    <el-button type="primary" icon="el-icon-close" @click="delGoodsInfo(index)"></el-button>
    <el-button
      type="primary"
      icon="el-icon-bottom"
      :disabled="index === clerkForm.relevanceGoods.length - 1"
      @click="downFieldOrder(index)"
    ></el-button>
    <el-button
      type="primary"
      icon="el-icon-top"
      :disabled="index === 0"
      @click="upFieldOrder(index)"
    ></el-button>
  </div>
</div>

-----------------------------------------------
// 上传图片时获取索引值
getIndex(index) {
  this.imgIndex = index; 
},
// 活动图片上传
beforeImgUpload(file) {
  var isLt2M = file.size / 1024 / 1024 < 2;
  if (!isLt2M) {
    this.$message.error("上传图片的大小不能超过 2M!");
    return false;
  }
  this.loadingUpload = true;
  uploadImg(file)
    .then(imgUrl => {
      this.clerkForm.relevanceGoods[this.imgIndex].activeBanner = imgUrl;
      this.loadingUpload = false;
    })
    .catch(err => {
      this.$message.error(err);
      this.loadingUpload = false;
    });
  return false;
},