//去掉UItableview headerview黏性
//- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
// if (scrollView == self.tableView)
// {
// CGFloat sectionHeaderHeight = YOUR_HEIGHT;
// 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);
// }
// }
//}