如何使用代码将UISearchController搜索栏放到导航栏上

let searchController = UISearchController(searchResultsController: nil)

searchController.searchBar.searchBarStyle = .minimal
searchController.searchBar.placeholder = "搜索"

navigationItem.titleView = searchController.searchBar

searchController.searchResultsUpdater = self
searchController.delegate = self

extension YourViewController: UISearchResultsUpdating {
    func updateSearchResults(for searchController: UISearchController) {
        // 根据搜索关键字更新搜索结果
    }
}

searchController.hidesNavigationBarDuringPresentation = true

import UIKit

class YourViewController: UIViewController, UISearchResultsUpdating, UISearchControllerDelegate {
    
    let searchController = UISearchController(searchResultsController: nil)
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        searchController.searchBar.searchBarStyle = .minimal
        searchController.searchBar.placeholder = "搜索"
        
        navigationItem.titleView = searchController.searchBar
        
        searchController.searchResultsUpdater = self
        searchController.delegate = self
    }
    
    func updateSearchResults(for searchController: UISearchController) {
        // 根据搜索关键字更新搜索结果
    }
}