UITableView Plain风格下组标签滚动

CGFloat sectionHeaderHeight = 34 * DBHeightScale;

CGFloat sectionFooterHeight = 32 * DBHeightScale;

CGFloat offsetY = scrollView.contentOffset.y;

if (offsetY >= 0 && offsetY <= sectionHeaderHeight){

scrollView.contentInset = UIEdgeInsetsMake(-offsetY, 0, -sectionFooterHeight, 0);

}else if(offsetY >= sectionHeaderHeight && offsetY <= scrollView.contentSize.height - scrollView.frame.size.height - sectionFooterHeight){

scrollView.contentInset = UIEdgeInsetsMake(-sectionHeaderHeight, 0, -sectionFooterHeight, 0);

}else if (offsetY >= scrollView.contentSize.height - scrollView.frame.size.height - sectionFooterHeight && offsetY <= scrollView.contentSize.height - scrollView.frame.size.height){

scrollView.contentInset = UIEdgeInsetsMake(-offsetY, 0, -(scrollView.contentSize.height - scrollView.frame.size.height - sectionFooterHeight), 0);

}