Custom subclass of UISearchDisplayController that overrides the default behaviour of hiding the navigation bar when becoming active.

SearchDisplayController.swift

import UIKit

/** Custom subclass of UISearchDisplayController that overrides the default behaviour of hiding the navigation bar when becoming active. */
class SearchDisplayController: UISearchDisplayController {
    override func setActive(visible: Bool, animated: Bool) {
        if self.active == visible {
            return
        }
        
        searchContentsController.edgesForExtendedLayout = .Bottom
        
        if let navigationController = searchContentsController.navigationController {
            navigationController.setNavigationBarHidden(true, animated: false)
        }
        
        super.setActive(visible, animated: animated)
        
        if let navigationController = searchContentsController.navigationController {
            navigationController.setNavigationBarHidden(false, animated: false)
        }
        
        if visible {
            searchBar.becomeFirstResponder()
        } else {
            searchBar.resignFirstResponder()
        }
    }
}