使用prepareForSegue为DetailViewController搜索栏

class DetailViewController: UIViewController, UISearchResultsUpdating {
    @IBOutlet weak var searchBar: UISearchBar!
    var searchController: UISearchController!

    override func viewDidLoad() {
        super.viewDidLoad()

        searchController = UISearchController(searchResultsController: nil)
        searchController.searchResultsUpdater = self
        searchController.obscuresBackgroundDuringPresentation = false
        searchController.searchBar = searchBar
        navigationItem.searchController = searchController
    }

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if let destinationVC = segue.destination as? DetailViewController {
            destinationVC.searchController = searchController
        }
    }

    func updateSearchResults(for searchController: UISearchController) {
        // 在这里实现搜索功能
    }
}