(iPhone/iOS) UISearchBar Scope Buttons cover first row of UITableView - iphone

Question

I know this question has been asked before, but I have yet to find a true solution. I have a UITableView with a UISearchBar as its tableHeaderView. Whenever the scope buttons appear, they cover the first row of the UITableView.
I have tried using UITableView.contentOffset to offset the UITableView by the height of the scope buttons, and this works until the user taps the UITableView or scrolls it, at which point the UITableView jumps back to its original offset.
The best I've been able to do is set the UISearchBar as a separate item in the view, and simply resize the UITableView dynamically to show or hide it when the user taps a search button. The only problem is that there is no animation, so the transition is sharp.
UPDATE: I solved the problem by implementing a UISearchDisplayController, as this was the cleanest and easiest solution to work with. The UISearchDisplayController automatically shows/hides the scope buttons and moves the UITableView down accordingly. I didn't do this at first because I wanted the UITableView to remain visible rather than initially being blacked out by the UISearchDisplayController, however I've come to realize that the blackout does not hinder any functionality; the user would not have initiated a search if he wanted to continue looking at the UITableView the way it was.

Answer 1

Ideas:
Set the tableHeaderView to a UIView that has the UISearchBar as its subview, and resize that UIView when the scope buttons appear. The UITableView will hopefully respond to that view changing its frame.
Set the UISearchBar as the content of the first cell of the UITableView and use (void)reloadRowsAtIndexPaths:(NSArray *)indexPaths withRowAnimation:(UITableViewRowAnimation)animation when the scope buttons hide or show. Return the proper height to have the cell animate to its new height.
Or you could use the method you describe (UISearchBar as a separate item in the view), and use an animation block to animate the transition so it's less sharp.
[UIView animateWithDuration:1.0 animations:^
{
//change table view frame here
}];

Answer 2

If you adjust the cell height of the header based on if the search controller is active or not, all works well
func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
var headerHeight: CGFloat = 0.0
if searchController.isActive
{
headerHeight = searchController.searchBar.frame.size.height
}
return headerHeight
}