HarmonyOS 网络视频如何下载到相册，可以在相册中看到？

操作步骤：

目前使用的是SaveButton安全控件下载的图片和视频，图片可正常下载保存到图库，视频下载后图库中看不到，此操作并没有申请任何权限，想请教一下如何可以下载到图库中或者用什么方法可以做到，当前代码如下：

SaveButton()
  .width(this.isShowRelevantMe ? '50%' : '100%')
  .height(40)
  .fontSize(12)
  .backgroundColor(Color.Black)
  .iconSize(16)
  .onClick(async (event: ClickEvent, result: SaveButtonOnClickResult) => {
    if (result === SaveButtonOnClickResult.SUCCESS) {
      const context: common.UIAbilityContext = getContext(this) as common.UIAbilityContext;
      // 免去权限申请和权限请求等环节，获得临时授权，保存对应图片
      if (this.fileList[this.imageIndex].fileType === 0) {
        DownloadUtils.saveHttpPhoto(this.fileList[this.imageIndex].filePath, context)
      } else if (this.fileList[this.imageIndex].fileType === 1) {
        DownloadUtils.saveHttpVideo(this.fileList[this.imageIndex].filePath, context)
      }
    } else {
      Toast.showToast('下载失败')
    }
  })

//保存图片
static async saveHttpPhoto(url: string, context: common.UIAbilityContext) {
  // 使用request下载图片并在回调函数中保存图片到相册
  http.createHttp().request(url,
    {
      method: http.RequestMethod.GET,
      connectTimeout: 60000,
      readTimeout: 60000
    },
    async (error: BusinessError, data: http.HttpResponse) => {
      if (error) {
        console.error(`http reqeust failed with. Code: ${error.code}, message: ${error.message}`);
      } else {
        if (http.ResponseCode.OK === data.responseCode) {
          let imageBuffer: ArrayBuffer = data.result as ArrayBuffer;
          try {
            // 获取相册路径
            let helper = photoAccessHelper.getPhotoAccessHelper(context);
            let uri = await helper.createAsset(photoAccessHelper.PhotoType.IMAGE, 'jpg')
            let file = await fileIo.open(uri, fileIo.OpenMode.READ_WRITE | fileIo.OpenMode.CREATE)
            // 写入文件
            await fileIo.write(file.fd, imageBuffer);
            // 关闭文件
            await fileIo.close(file.fd);
            Toast.showToast('已保存至相册');
          } catch (error) {
            console.error("error is " + JSON.stringify(error))
            Toast.showToast("error is " + JSON.stringify(error));
          }
        } else {
          console.error("error occurred when image downloaded!")
          Toast.showToast("error occurred when image downloaded!")
        }
      }
    })
}

//保存视频
static async saveHttpVideo(url: string, context: common.UIAbilityContext) {
  // 使用request下载图片并在回调函数中保存图片到相册
  http.createHttp().request(url,
    {
      method: http.RequestMethod.GET,
      connectTimeout: 60000,
      readTimeout: 60000
    },
    async (error: BusinessError, data: http.HttpResponse) => {
      if (error) {
        console.error(`http reqeust failed with. Code: ${error.code}, message: ${error.message}`);
      } else {
        if (http.ResponseCode.OK === data.responseCode) {
          let imageBuffer: ArrayBuffer = data.result as ArrayBuffer;
          try {
            // 获取相册路径
            let helper = photoAccessHelper.getPhotoAccessHelper(context);
            let uri = await helper.createAsset(photoAccessHelper.PhotoType.VIDEO, 'mp4')
            let file = await fileIo.open(uri, fileIo.OpenMode.READ_WRITE | fileIo.OpenMode.CREATE)
            // 写入文件
            await fileIo.write(file.fd, imageBuffer);
            // 关闭文件
            await fileIo.close(file.fd);
            Toast.showToast('已保存至相册');
          } catch (error) {
            console.error("error is " + JSON.stringify(error))
            Toast.showToast("error is " + JSON.stringify(error));
          }
        } else {
          console.error("error occurred when image downloaded!")
          Toast.showToast("error occurred when image downloaded!")
        }
      }
    })
}