ios - UISearchBar presented by UISearchController in table header view animates too far when active

Question

I am using UISearchController to present a search bar inside the header view of a tableview:

...
self.searchController.hidesNavigationBarDuringPresentation = NO;            
self.presentingTVC.tableView.tableHeaderView = self.searchController.searchBar;
[self.searchController.searchBar sizeToFit];
self.presentingTVC.tableView.tableHeaderView = self.searchController.searchBar;

(where setting the tableHeaderView property twice is necessary as otherwise the header view overlaps the first row, c.f.a couple of answers on S.O. )

This is how it looks, perfectly in position when inactive:

The search bar should just stay in place when active - I don't want it to move up to hide the navigation bar. But it unexpectedly animates down, leaving a blank space between it and the navigation bar:

Here's a video of weird search bar animation

If I just use a search bar separately from UISearchController, it does not show the same behaviour when it becomes active.

In my presenting view controller, I have self.definesPresentationContext = YES; and self.navigationController.navigationBar.translucent = YES;, and in IB none of the "extend edges" boxes are active (all seemed to be possible things that could throw search presentation off, from reading around).

Does anyone know how I can stop the search bar from animating down?

Answer 1

Old question but I was able to solve this issue by setting

self.extendedLayoutIncludesOpaqueBars = YES;

on my view controller. I think is issue is caused by having an opaque navigation bar but setting hidesNavigationBarDuringPresentation to NO on your search controller, causing the search bar to incorrectly position itself when focused.