UITableView UITableViewStylePlain模型下 取消headerView的黏结性

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
    CGFloat sectionHeaderHeight =44;
    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);
    }
}