HarmonyOS APP 跳转相册 /相机， 选择照片后，返回uris， 怎么读取出来？

selectedPhoto() { 
  const photoSelectOptions = new photoAccessHelper.PhotoSelectOptions(); 
  photoSelectOptions.MIMEType = photoAccessHelper.PhotoViewMIMETypes.IMAGE_TYPE; // 过滤选择媒体文件类型为VIDEO 
  photoSelectOptions.maxSelectNumber = 1; // 选择媒体文件的最大数目 
  let uris: Array<string> = []; 
  const photoViewPicker = new photoAccessHelper.PhotoViewPicker(); 
  photoViewPicker.select(photoSelectOptions).then(async (photoSelectResult: photoAccessHelper.PhotoSelectResult) => { 
    uris = photoSelectResult.photoUris; 
    console.info('photoViewPicker.select to file succeed and uris are:' + uris); 
    let file = fs.openSync(uris[0], fs.OpenMode.READ_ONLY); 
    console.info('file fd:' + file.fd); 
    const imageSource: image.ImageSource = image.createImageSource(file.fd); 
    let decodingOptions: image.DecodingOptions = { 
      editable: true, 
      desiredPixelFormat: 3, 
    } 
    let selectedImgPixelMap = await imageSource.createPixelMap(decodingOptions); 
    let imageBuffer = await this.packingPixelMap2Jpg(selectedImgPixelMap) 
    console.log('ArrayBuffer = ' + imageBuffer.byteLength) 
 
  }).catch((err: BusinessError) => { 
    console.error(`Invoke photoViewPicker.select failed, code is ${err.code}, message is ${err.message}`); 
  }) 
} 
 
// 打包 PixelMap 为 jpg 格式 
async packingPixelMap2Jpg(pixelMap: PixelMap): Promise<ArrayBuffer> { 
  // 创建ImagePacker实例 
  const imagePackerApi = image.createImagePacker(); 
  // 设置打包参数 
  // format：图片打包格式，只支持 jpg 和 webp 
  // quality：JPEG 编码输出图片质量 
  // bufferSize：图片大小，默认 10M 
  const packOpts: image.PackingOption = { format: "image/jpeg", quality: 100 }; 
  let imageBuffer: ArrayBuffer = new ArrayBuffer(1); 
  try { 
  // 图片压缩或重新打包 
  imageBuffer = await imagePackerApi.packing(pixelMap, packOpts); 
} catch (err) { 
  console.error(`Invoke packingPixelMap2Jpg failed, err: ${JSON.stringify(err)}`); 
} 
return imageBuffer; 
}