Swift - 导航视图控制器不出现标题

Question

我有一个导航视图控制器,在操作时将一个segue发送到标签栏视图控制器.由于此segue,选项卡式视图控制器继承导航栏.我正在尝试将标题应用于附加到标签栏视图控制器的我的一个视图控制器,但是通过代码设置标题对我来说不起作用.有谁知道原因可能是什么？

这是我的故事板的图片:

带有注销按钮的视图控制器是我试图在导航栏(代码)中设置标题的地方:

import UIKit

class ProfileSettingsViewController: UIViewController {

    override func viewWillAppear(animated: Bool) {

        self.navigationItem.title = "Profile Settings"

    }

    override func viewDidLoad() {
        super.viewDidLoad()

        self.navigationItem.leftBarButtonItem = nil


    }



    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }



    @IBAction func logoutButton(sender: AnyObject) {

        PFUser.logOut()
        var currentUser = PFUser.currentUser()
        self.performSegueWithIdentifier("userLoggedOut", sender: self)
        self.navigationController?.setNavigationBarHidden(self.navigationController?.navigationBarHidden == false, animated: true)

    }

}

嵌入导航控制器的视图控制器触发到标签栏控制器的segue:

import UIKit

class UserRegistrationViewController: UIViewController {


    func displayAlert(title:String, error:String) {

        var alert = UIAlertController(title: title, message: error, preferredStyle: UIAlertControllerStyle.Alert)

        alert.addAction(UIAlertAction(title: "OK", style: .Default, handler: {
            action in



        }))

        self.presentViewController(alert, animated: true, completion: nil)


    }

    @IBOutlet var usernameTextField: UITextField!

    @IBOutlet var emailTextField: UITextField!

    @IBOutlet var passwordTextField: UITextField!


    override func viewDidLoad() {
        super.viewDidLoad()


    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


    @IBAction func registerUser(sender: AnyObject) {

        var error = ""

        if usernameTextField.text == nil || emailTextField.text == nil || passwordTextField.text == nil {

            error = "Please enter a username, email and password"

        }


        if error != "" {

            displayAlert("Error In Form", error: error)

        } else {

            var user = PFUser.currentUser()

            user.username = usernameTextField.text
            user.password = passwordTextField.text
            user.email = emailTextField.text

            user.saveInBackgroundWithBlock {
                (succeeded: Bool!, signupError: NSError!) -> Void in
                if signupError == nil {

                    println(user.username)
                    println(user.password)
                    println(user.email)


                    self.performSegueWithIdentifier("successfulRegistration", sender: self)

                    self.navigationController?.setNavigationBarHidden(self.navigationController?.navigationBarHidden == false, animated: true)

                    // Hooray! Let them use the app now.
                } else {

                    if let errorString = signupError.userInfo?["error"] as? NSString {
                        error = errorString
                    } else {

                        error = "Please try again later."

                    }


                    self.displayAlert("Could Not Sign Up", error: error)

                }
            }


        }


    }



}

Answer 1

在视图控制器层次结构中,导航栏显示的是标题UITabBarController,而不是视图控制器UITabBarController.

在导航栏中显示标题的最简单方法是

override func viewWillAppear(animated: Bool) {

    self.tabBarController?.navigationItem.title = "Profile Settings"

}

Answer 2

这对我有用: self.parent?.title = "nav bar title"

Answer 3

尝试这个：

self.navigationController?.navigationBar.topItem?.title = "Profile Settings"

Answer 4

SWIFT 3

如果嵌入在UINavigationController中，则可以在ViewController的viewDidLoad（）方法中按如下所示设置标题。

override func viewDidLoad() {
    super.viewDidLoad()

    /* If view controller is a direct child of UINavigationController */
    self.title = "Title Here"

    /* If view controller's parent is a direct child of UINavigationController e.g. a child of embedded tab view controller */
    self.parent?.title = "Title Here" 
}

Answer 5

在“注销屏幕”视图控制器中添加以下内容-

self.tabBarController?.navigationItem.title="Profile Settings"