element-ui中使用多个el-upload组件时无法绑定对应的元素

<el-upload class="ry-uploader"
       action="" 
       :show-file-list="false"
       :on-success="handleImgUploadSuccess"
       :before-upload="(res) => {return beforeImgUpload(res,'B1')}"
       :http-request="uploadImgRequest"
    >
    <img v-if="imageUrlObject.B1" :src="imageUrlObject.B1" class="avatar">
    <i v-else class="el-icon-plus avatar-uploader-icon"></i>
</el-upload>

:before-upload="(res) => {return beforeImgUpload(res,'B1')}"