iOS tableView上滑和下滑

//记录拖动时候的offset
-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView{
    self.contentOffset = scrollView.contentOffset.y;
}


-(void)scrollViewDidScroll:(UIScrollView *)scrollView{
    CGFloat newOffsetY = scrollView.contentOffset.y;
     if (newOffsetY > self.oldOffset && self.oldOffset > self.contentOffset){//上滑
            //写上滑代码
        }else if(newOffsetY < self.oldOffset && self.oldOffset < self.contentOffset){//下滑
            //写下滑代码
        }
       self.oldOffset = scrollView.contentOffset.y;
}
//记录滑动结束时候的offset
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
    self.oldOffset = scrollView.contentOffset.y;
}