如何防止UISearchController显示导航栏？

class ViewController: UIViewController {
    var searchController: UISearchController!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        searchController = UISearchController(searchResultsController: nil)
        searchController.hidesNavigationBarDuringPresentation = true
        
        // 其他UISearchController的设置
        
        navigationItem.searchController = searchController
    }
    
    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        
        searchController.hidesNavigationBarDuringPresentation = false
    }
}