arco-design upload上传 监听progress事件

Question

问题遇到的现象和发生背景

字节arco-design
a-upload多种附件上传

用代码块功能插入代码，请勿粘贴截图

   <div style="align-self: start;margin-left:10px;">
                        <a-upload class="uploader" :action="UPLOAD_URL" name="file" multiple accept=".pdf"
                            :fileList="item.files ? item.files : []"
                            :show-file-list="false"
                            @before-upload="beforeUpload"
                            @change="function(fileList,fileItem){return onUploadChange(fileList,fileItem,item)}"
                            @progress="onUploadProgress"
                            @success="function(fileItem){onUploadSuccess(fileItem,item)}"
                            @error="onUploadError(item)">
                            <a-button :type="item.isOk ? 'success' : 'danger'" plain
                                icon="icon-upload">点击上传文件1</a-button>
                        </a-upload>