让UITableView的section header view不悬停的方法

// 让UITableView的section header view不悬停的方法- (void)scrollViewDidScroll:(UIScrollView *)scrollView{    CGFloat sectionHeaderHeight = 40;    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);    }}