uitableview 无需关联delegate 只需要再uitabviewcontrller 中添加上

UIScrollViewDelegate

int lastContentOffset;

-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {

    lastContentOffset = scrollView.contentOffset.y;

}

-(void)scrollViewDidScroll:(UIScrollView *)scrollView {

    if (scrollView.contentOffset.y<lastContentOffset)

    {

        [self.navigationControllersetNavigationBarHidden:NOanimated:YES];

//向上

    } else if (scrollView.contentOffset.y>lastContentOffset)

    {

        [self.navigationControllersetNavigationBarHidden:YESanimated:YES];

//向下

    }

}