// 滚动停止的时候再去获取image的信息来显示在UITableViewCell上
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate {
if(!decelerate){
[self loadImagesForOnscreenRows];
}
}
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
[self loadImagesForOnscreenRows];
}