HarmonyOS生产的二维码图保存到本地图片无效

async createImageToSave() { 
  let options: generateBarcode.CreateOptions = { 
    scanType: scanCore.ScanType.QR_CODE, 
    height: 400, 
    width: 400 
  } 
  // 码图生成接口，成功返回PixelMap格式图片 
  generateBarcode.createBarcode(“华为”, options).then((pixelMap: image.PixelMap) => { 
    let buf = new ArrayBuffer(pixelMap.getPixelBytesNumber()) 
    pixelMap.readPixelsToBuffer(buf).then((value) => { 
      console.log("二维码:" + buf.byteLength) 
      CustomFileSaveManager.saveImageToPhoto(buf) 
    }) 
  }) 
} 
static async saveImageToPhoto(buffer: ArrayBuffer | string): Promise<void> { 
  const context = getContext() as common.UIAbilityContext; // 获取getPhotoAccessHelper需要的context 
  const helper = photoAccessHelper.getPhotoAccessHelper(context); // 获取相册管理模块的实例 
  const uri = await helper.createAsset(photoAccessHelper.PhotoType.IMAGE, 'jpg'); // 指定待创建的文件类型、后缀和创建选项，创建图片或视频资源 
  const file = await fs.open(uri, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE); 
  let r =  await fs.write(file.fd, buffer); 
  await fs.close(file.fd); 
  showShortCenterToast("图片保存成功") 
}