@Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setRetainInstance(true);
    setHasOptionsMenu(true);

    updateItems();

    mThumbnailThread = new ThumbnailDownloader(new Handler());
    mThumbnailThread.start();
  }
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setRetainInstance(true);
    setHasOptionsMenu(true);

    updateItems();
    //        启动IntentService在onCreatView里通过按钮单击实现了
    //        Intent i = new Intent(getActivity(),PollService.class);
    //        getActivity().startService(i);

    mThumbnailThread = new ThumbnailDownloader(new Handler());
    mThumbnailThread.start();
  }
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setRetainInstance(true);
    setHasOptionsMenu(true);
    updateItems();

    Handler responseHandler = new Handler();
    mThumbnailDownloader = new ThumbnailDownloader<>(responseHandler);
    mThumbnailDownloader.setThumbnailDownloadeListener(
        new ThumbnailDownloader.ThumbnailDownloadListener<PhotoHolder>() {
          @Override
          public void onThumbnailDownloaded(PhotoHolder photoHolder, Bitmap bitmap) {
            Drawable drawable = new BitmapDrawable(getResources(), bitmap);
            photoHolder.bindDrawable(drawable);
          }
        });

    mThumbnailDownloader.start();
    mThumbnailDownloader.getLooper();
    Log.i(TAG, "Background thread started");
  }
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setRetainInstance(true);
    setHasOptionsMenu(true);

    updateItems();

    // PollService.setServiceAlarm(getActivity(), true);

    mThumbnailThread = new ThumbnailDownloader<ImageView>(new Handler());
    mThumbnailThread.setListener(
        new ThumbnailDownloader.Listener<ImageView>() {
          @Override
          public void onThumbnailDownloaded(ImageView imageView, Bitmap bitmap) {
            if (isVisible()) {
              imageView.setImageBitmap(bitmap);
            }
          }
        });
    mThumbnailThread.start();
    mThumbnailThread.getLooper();
    Log.i(TAG, "Background thread started");
  }