VUE+iView 包含多个upload组件时，在on-success里面传参

有多个Upload组件，上传图片时需要知道是第几个Upload组件

 <div v-for="(bannerForm, index) in banner" :key="index">
   <Form :ref="bannerForm" :model="bannerForm">
     <Upload
                    ref="upload"
                    :on-success="(value)=> handleSuccess(index, value)" //关键
                    :action="action"
                  >
                    <img
                      :src="gxWebUrl + bannerForm.pictureUrl"
                    />
     </Upload>
   </Form>
 </div>

  handleSuccess(index, value) {
       this.banner[index].pictureUrl = value.data
    },