HarmonyOS axios如何上传多张图片

请问一次性上传多张图片，在上传多张图片，想问下：

1、多张图片如何传值？

2、请求参数和图片流怎么传值？

因此想知道一次性上传多张图片的解决方案

如下demo报错：Buffer is not defined code==ERR_BAD_OPTION_VALUE

//上传文件
uploadFile(buffer:ArrayBuffer,uploadUrl: string, fileName: string, fileContentType: string,
paramsMap: Map<string, string>): Promise<http.HttpResponse> {
  return new Promise<http.HttpResponse>(async (resolver, reject) => {
  try {
  let param:param = {
    aid: paramsMap.get('aid') as string,
    sid: paramsMap.get('sid')as string,
    token: paramsMap.get('token')as string,
    ext: JSON.parse(paramsMap.get('ext')as string) as object,
    ts: paramsMap.get('ts')as string,
    sign: paramsMap.get('sign')as string,
    image_files: [buffer,buffer],
    sceneId: '',
    fromType:''
  }

  let fileName = 'certImage'+systemDateTime.getTime().toString()

  let formData = new FormData()

  formData.append('file',buffer)
  formData.append('name','image_files')
  formData.append('fileName',fileName)
  axios.post<string,AxiosResponse<string>,FormData>(uploadUrl,formData,{
  method:'post',
  params:param,
  data:formData,
  headers:{'Content-Type': 'multipart/form-data'},
  context:getContext(this),
  onUploadProgress:(progress: AxiosProgressEvent): void =>{
    console.info('AxiosProgressEvent'+progress)
  }
})
.then((res:AxiosResponse)=>{
  console.info('Axiosres'+JSON.stringify(res))
}).catch((err:AxiosError)=>{
  console.info('error message='+err.message+' code=='+err.code)
})
catch (e) {
  reject(e)
}
}
})
}