tableview滑动 section随cell一起滑动不停留

tableview group类型的滑动时，section会有悬停的状态，改变这个悬停使其和正常cell一样滑动代码如下：

#pragma mark - UIScrollView -- delegate
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    CGFloat sectionHeaderHeight = kTaskSectionHeaderHeight;
    if (scrollView.contentOffset.y <= sectionHeaderHeight && scrollView.contentOffset.y > 0) {
        scrollView.contentInset = UIEdgeInsetsMake(-scrollView.contentOffset.y, 0, 0, 0);
    } else {
        if (scrollView.contentOffset.y >= sectionHeaderHeight) {
            scrollView.contentInset = UIEdgeInsetsMake(-sectionHeaderHeight, 0, 0, 0);
        }
    }
}