Ios 如何使用代码将UISearchController搜索栏放在导航栏上

如果将ViewController嵌入导航栏，

navigationItem.titleView.resultSearchController？.searchBar

将在导航栏中插入搜索栏。但是，我创建了一个UISearchController和一个带有代码的UINavigationBar。这一次，导航栏出现了，但搜索栏没有出现

resultSearchController = UISearchController(searchResultsController: locationSearchTable)
resultSearchController?.searchResultsUpdater = locationSearchTable

let searchBar = resultSearchController!.searchBar
searchBar.sizeToFit()
searchBar.delegate = self

let navBar: UINavigationBar = UINavigationBar(frame: CGRect(x: 0, y:0, width: 375, height: 64))
self.view.addSubview(navBar)
//navBar.topItem = resultSearchController?.searchBar
self.navigationItem.titleView = resultSearchController?.searchBar

---

navBar.topItem=resultSearchController？.searchBar

不工作，因为

topItem

是字符串值，而

resultSearchController？.searchBar

是

UIView

类型。如何实现相同的效果？

创建一个

UINavigationItem

实例，并将其添加到创建的导航栏中。

class UIViewController: UIViewController, UISearchControllerDelegate, UISearchResultsUpdating, UISearchBarDelegate {

    var searchController : UISearchController!

    override func viewDidLoad() {
        super.viewDidLoad()

        self.searchController = UISearchController(searchResultsController:  nil)

        self.searchController.searchResultsUpdater = self
        self.searchController.delegate = self
        self.searchController.searchBar.delegate = self

        self.searchController.hidesNavigationBarDuringPresentation = false
        self.searchController.dimsBackgroundDuringPresentation = true

        self.navigationItem.titleView = searchController.searchBar

        self.definesPresentationContext = true
    }

    func updateSearchResults(for searchController: UISearchController) {

    }


}

将搜索控制器搜索栏作为标题视图添加到UINavigationItem

class SearchViewController: UIViewController, UISearchControllerDelegate, UISearchResultsUpdating, UISearchBarDelegate {

    var searchController: UISearchController!

    override func viewDidLoad() {
        super.viewDidLoad()
        self.addNavigationbar()
    }

    func addNavigationbar() {
        let navBar = UINavigationBar(frame: CGRect(x: 0, y: 0, width: self.view.frame.size.width, height: 60))
        self.view.addSubview(navBar)

        let navigationItem = UINavigationItem(title: "")
        self.searchController = searchControllerWith(searchResultsController: nil)
        navigationItem.titleView = self.searchController.searchBar

        navBar.setItems([navigationItem], animated: false)
        self.definesPresentationContext = true
    }

    func searchControllerWith(searchResultsController: UIViewController?) -> UISearchController {

        let searchController = UISearchController(searchResultsController: searchResultsController)
        searchController.delegate = self
        searchController.searchResultsUpdater = self
        searchController.searchBar.delegate = self
        searchController.hidesNavigationBarDuringPresentation = false
        searchController.dimsBackgroundDuringPresentation = true

        return searchController
    }

---

此代码中没有创建导航栏。假设您将VC嵌入导航栏中，此代码将正常工作。我的问题是如何使搜索栏成为我用代码创建的导航栏的标题视图