实现方法一：
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
if (scrollView == self.myTableView)
{
CGFloat sectionHeaderHeight = 44.0f;
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);
}
}
}
