ios - 不在导航栏上制作栏按钮项目和标题(iOS，Swift)

Question

在我的主导航 Controller 上，有一个名为“Next Page” 的右栏按钮。按下按钮时，它会调用名为 "nextPage()" 的方法，该方法会初始化导航 Controller 并显示它。

nextPage() 的代码如下:

func nextPage() {
        let window = UIWindow(frame: UIScreen.mainScreen().bounds)
        let CustomLoginVC = UIStoryboard(name: "Main", bundle: nil).instantiateViewControllerWithIdentifier("viewControllerID") as! customVC

        let navVC = UINavigationController.init(rootViewController: CustomLoginVC)
        navVC.view.autoresizingMask = [.FlexibleHeight, .FlexibleWidth, .FlexibleTopMargin, .FlexibleLeftMargin]

        navVC.navigationBar.translucent = false
        navVC.navigationItem.title = "haha"
        navVC.navigationBar.tintColor = UIColor.whiteColor()
        navVC.navigationBar.titleTextAttributes = [NSFontAttributeName: UIFont(name: "AvenirNext-Medium", size: 22)!, NSForegroundColorAttributeName: UIColor.whiteColor() ]
        navVC.navigationItem.leftBarButtonItem?.setTitleTextAttributes([NSFontAttributeName: UIFont(name: "AvenirNext", size: 18)!], forState: UIControlState.Normal)

        let backButton = UIBarButtonItem.init(title: "Back", style: UIBarButtonItemStyle.Plain, target: self, action: "backButtonPressedInPDF")
        let exportButton = UIBarButtonItem.init(image: UIImage(named: "export"), style: UIBarButtonItemStyle.Plain, target: self, action: "saveAsPDF")

        navVC.navigationItem.setLeftBarButtonItem(backButton, animated: false)
        navVC.navigationItem.setRightBarButtonItem(exportButton, animated: false)
        window.rootViewController = navVC
        self.presentViewController(navVC, animated: true, completion: nil)
    }

如您所见，我正在实例化 CustomLoginVC，它是主 Storyboard中的一种 customVC。 customVC 是 UIViewController 的子类。然后，使用 CustomLoginVC 初始化 UINavigationController 并分配左右栏按钮项。但是，标题和栏按钮项未显示在导航栏上，如下图所示。

我不明白为什么导航栏上没有栏按钮项目和标题。

同样在 AppDelegate 中，我设置了如下方法:

  func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
        UINavigationBar.appearance().barTintColor = UIColor(hex: "00BFA5")
        application.statusBarStyle = UIStatusBarStyle.LightContent

        return true
    }

如有任何意见，我们将不胜感激!

Answer 1

您需要在 CustomLoginVC 上设置标题和按钮，而不是在 navVC 上设置