//去掉UItableview headerview黏性(sticky)
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
CGFloat sectionHeaderHeight = 250; //section的高度
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);
}
}