@Override
 public void onScrollStateChanged(AbsListView view, int scrollState) {
   super.onScrollStateChanged(view, scrollState);
   if (scrollState == SCROLL_STATE_IDLE) {
     // 停止滑动,日期指示器消失
     mTimeLineText.setVisibility(View.GONE);
   } else if (scrollState == SCROLL_STATE_FLING) {
     mTimeLineText.setVisibility(View.VISIBLE);
   }
 }
 @Override
 public void onScroll(
     AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
   super.onScroll(view, firstVisibleItem, visibleItemCount, totalItemCount);
   if (mTimeLineText.getVisibility() == View.VISIBLE) {
     int index =
         firstVisibleItem + 1 == view.getAdapter().getCount()
             ? view.getAdapter().getCount() - 1
             : firstVisibleItem + 1;
     Image image = (Image) view.getAdapter().getItem(index);
     if (image != null) {
       mTimeLineText.setText(TimeUtil.formatPhotoDate(image.path));
     }
   }
 }