HarmonyOS 鸿蒙Next 将image.PixelMap类型的图片保存到本地，保存成功但是需要杀应用后台系统相册才会显示照片

需要杀掉进程才可以保存成功，应该是文件资源没有释放，所以没有保存结束，当杀掉进程，自动回收资源，保存成功。

import { resourceManager } from '@kit.LocalizationKit';
import { photoAccessHelper } from '@kit.MediaLibraryKit';
import { BusinessError } from '@kit.BasicServicesKit';
import { image } from '@kit.ImageKit';
import { promptAction } from '@kit.ArkUI';
import { fileIo } from '@kit.CoreFileKit';

@Entry
@Component
struct SavePixelMapToAlbum {
  @State saveButtonOptions: SaveButtonOptions = {
    icon: SaveIconStyle.FULL_FILLED,
    text: SaveDescription.SAVE,
    buttonType: ButtonType.Capsule
  };
  @State pixel: image.PixelMap | undefined = undefined;
  @State albumPath: string = '';
  @State photoSize: number = 0;
  private context: Context = getContext(this);

  async aboutToAppear() {
    const resourceMgr: resourceManager.ResourceManager = this.context.resourceManager;
    const fileData: Uint8Array = await resourceMgr.getRawFileContent('rawfile/test.png');
    let buffer = new Uint8Array(fileData).buffer as object as ArrayBuffer;
    let imageResource = image.createImageSource(buffer);
    let opts: image.DecodingOptions = { editable: true };
    this.pixel = await imageResource.createPixelMap(opts);
  }

  async savePixelMapToAlbum() {
    let imagePackerApi = image.createImagePacker();
    let packOpts: image.PackingOption = { format: 'image/jpeg', quality: 98 };

    imagePackerApi.packing(this.pixel, packOpts).then(async (buffer: ArrayBuffer) => {
      try {
        let helper = photoAccessHelper.getPhotoAccessHelper(this.context)
        let uri = await helper.createAsset(photoAccessHelper.PhotoType.IMAGE, 'png')
        let file = await fileIo.open(uri, fileIo.OpenMode.READ_WRITE | fileIo.OpenMode.CREATE)
        await fileIo.write(file.fd, buffer);
        // 关闭文件
        await fileIo.close(file.fd);
        promptAction.showToast({ message: '已保存至相册！' });
      } catch (error) {
        console.error("保存失败：" + JSON.stringify(error))
      }
    }).catch((error: BusinessError) => {
      console.error('保存失败，失败原因: ' + error);
    })
  }

  build() {
    Row() {
      Column() {
        Image(this.pixel)
          .objectFit(ImageFit.None)
          .height('30%')

        SaveButton(this.saveButtonOptions)
          .onClick(async (event, result: SaveButtonOnClickResult) => {
            if (result === SaveButtonOnClickResult.SUCCESS) {
              this.savePixelMapToAlbum();
            }
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}