本文介绍了试图弹出一个不存在的视图控制器 swift 5.1 Xcode iOS的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在开发应用程序.当我点击注销按钮时，它向我显示了这个错误试图弹出一个不存在的视图控制器.
i'm Working on App. when i'm clicking on logout button its shows me this error Tried to pop to a view controller that doesn't exist.
这是我的 StoryBoard 屏幕
这是我的 AppDelegate 代码
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
// Override point for customization after application launch.
if #available(iOS 13.0, *)
{
//do nothing we will have a code in SceneceDelegate for this
}
else {
makeRoot()
}
FirebaseApp.configure()
return true
}
func makeRoot()
{
let defaults = UserDefaults.standard
if defaults.bool(forKey: "isLogin") == true
{
let mainStoryboard = UIStoryboard(name: "Main", bundle: nil)
let VC = mainStoryboard.instantiateViewController(withIdentifier: "RootTabBarC") as! RootTabBarC
let centerNavVC = UINavigationController(rootViewController: VC)
//centerNavVC.isNavigationBarHidden = true
self.window = UIWindow(frame: UIScreen.main.bounds)
self.window?.rootViewController = centerNavVC
self.window?.makeKeyAndVisible()
}
else
{
let mainStoryboard = UIStoryboard(name: "Main", bundle: nil)
let VC = mainStoryboard.instantiateViewController(withIdentifier: "LoginSignUpVC") as! LoginSignUpVC
let centerNavVC = UINavigationController(rootViewController: VC)
//centerNavVC.isNavigationBarHidden = true
self.window = UIWindow(frame: UIScreen.main.bounds)
self.window?.rootViewController = centerNavVC
self.window?.makeKeyAndVisible()
}
}
这是我的 SceneDelagate 代码
func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
// Use this method to optionally configure and attach the UIWindow `window` to the provided UIWindowScene `scene`.
// If using a storyboard, the `window` property will automatically be initialized and attached to the scene.
// This delegate does not imply the connecting scene or session are new (see `application:configurationForConnectingSceneSession` instead).
guard let windowScene = (scene as? UIWindowScene) else { return }
let defaults = UserDefaults.standard
if defaults.bool(forKey: "isLogin") == true
{
//guard let windowScene = (scene as? UIWindowScene) else { return }
self.window = UIWindow(windowScene: windowScene)
//self.window = UIWindow(frame: UIScreen.main.bounds)
let storyboard = UIStoryboard(name: "Main", bundle: nil)
guard let rootVC = storyboard.instantiateViewController(identifier: "RootTabBarC") as? RootTabBarC else {
print("ViewController not found")
return
}
let navVc = UINavigationController(rootViewController: rootVC)
//navVc.isNavigationBarHidden = true
self.window?.rootViewController = navVc
self.window?.makeKeyAndVisible()
}
else
{
self.window = UIWindow(windowScene: windowScene)
//self.window = UIWindow(frame: UIScreen.main.bounds)
let storyboard = UIStoryboard(name: "Main", bundle: nil)
guard let rootVC = storyboard.instantiateViewController(identifier: "LoginSignUpVC") as? LoginSignUpVC else {
print("ViewController not found")
return
}
let navVc = UINavigationController(rootViewController: rootVC)
//navVc.isNavigationBarHidden = true
self.window?.rootViewController = navVc
self.window?.makeKeyAndVisible()
}
}
这是我的 LoginSignUpVc 代码
import UIKit
class LoginSignUpVC: UIViewController {
@IBOutlet weak var lblTitle: UILabel!
@IBOutlet weak var btnLogin: UIButton!
@IBOutlet weak var lblDontHaveAccount: UILabel!
@IBOutlet weak var btnSignUp: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
setupUI()
}
override func viewWillAppear(_ animated: Bool) {
navigationController?.setNavigationBarHidden(false, animated: true)
}
override var prefersStatusBarHidden: Bool
{
return true
}
func setupUI()
{
letterSpacing()
buttonSetUp()
}
@IBAction func onClickLogin(_ sender: Any)
{
}
@IBAction func onClickSignUp(_ sender: Any)
{
}
}
这是我的 LoginVc 代码
import UIKit
import FirebaseAuth
class LoginVC: UIViewController {
@IBOutlet weak var lblTitle: UILabel!
@IBOutlet weak var lblSubTitle: UILabel!
@IBOutlet weak var viewContainerEmail: UIView!
@IBOutlet weak var txtEmail: UITextField!
@IBOutlet weak var viewContainerPassword: UIView!
@IBOutlet weak var txtPassword: UITextField!
@IBOutlet weak var btnLogin: SSSpinnerButton!
@IBOutlet weak var btnForgotPassword: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
navigationController?.navigationBar.layer.frame.origin.y = 22
setupUI()
}
override func viewWillDisappear(_ animated: Bool) {
btnLogin.stopAnimate(complete: nil)
}
override var prefersStatusBarHidden: Bool
{
return true
}
func setupUI()
{
letterSpacing()
textFieldSetUp()
buttonSetUp()
}
@IBAction func onClickLogin(_ sender: Any)
{
let email = Validation.shareValidator.isValidEmail(email: txtEmail.text, view: viewContainerEmail)
let password = Validation.shareValidator.isValidPassword(password: txtPassword.text, view: viewContainerPassword)
if email != "success"
{
CustomAlert.shareAlert.alertSetUp(title: "Email Field", subTitle: email, boldTitle: "Invalid Email")
}
else if password != "success"
{
CustomAlert.shareAlert.alertSetUp(title: "Password Field", subTitle: password, boldTitle: "Invalid Password")
}
else
{
Auth.auth().signIn(withEmail: txtEmail.text!, password: txtPassword.text!) { (result, error) in
if error != nil
{
CustomAlert.shareAlert.alertSetUp(title: "Login Error", subTitle: error!.localizedDescription, boldTitle: "Login Error")
}
else
{
self.btnLogin.startAnimate(spinnerType: SpinnerType.circleStrokeSpin, spinnercolor: UIColor.white, spinnerSize: 20, complete: {
self.btnLogin.backgroundColor = UIColor.green
let defaults = UserDefaults.standard
defaults.set(true, forKey: "isLogin")
defaults.set(result?.user.uid, forKey: "uid")
defaults.set(self.txtEmail.text!, forKey: "email")
//let st = UIStoryboard(name: "Main", bundle: nil)
let vc = self.storyboard?.instantiateViewController(withIdentifier: "RootTabBarC") as! RootTabBarC
self.navigationController?.pushViewController(vc, animated: true)
})
}
}
}
}
@IBAction func onClickBack(_ sender: Any)
{
navigationController?.popViewController(animated: true)
}
}
这是我的 ProfileVC 代码
import UIKit
import FirebaseAuth
import FirebaseDatabase
import Kingfisher
class ProfileVC: UIViewController {
@IBOutlet weak var viewImageContainer: UIView!
@IBOutlet weak var imgProfile: UIImageView!
@IBOutlet weak var lblName: UILabel!
@IBOutlet weak var lblDishExpert: UILabel!
@IBOutlet weak var lblBio: UILabel!
@IBOutlet weak var imgEmailIcon: UIImageView!
@IBOutlet weak var imgPhoneIcon: UIImageView!
@IBOutlet weak var lblEmail: UILabel!
@IBOutlet weak var lblPhone: UILabel!
var userDataDict = [String]()
override func viewDidLoad() {
super.viewDidLoad()
setUpUI()
showUserData()
}
@IBAction func onClickLogOut(_ sender: Any)
{
do
{
try Auth.auth().signOut()
UserDefaults.standard.set(false, forKey: "isLogin")
UserDefaults.standard.removeObject(forKey: "uid")
UserDefaults.standard.removeObject(forKey: "email")
UserDefaults.standard.synchronize()
}
catch let err
{
print(err.localizedDescription)
}
let vc = storyboard?.instantiateViewController(identifier: "LoginSignUpVC") as? LoginSignUpVC
navigationController?.popToViewController(vc!, animated: true)
}
}
我也在尝试 self.parent?.navigationController?.PopToRootViewController(animate:true)但不能正常工作.感谢您的帮助.
i'm also try self.parent?.navigationController?.PopToRootViewController(animate:true)but is not working propely.thank for your help.
推荐答案
Vasucd 是对的，先把 LoginSinUpVC 放在 NavigationController 的 viewControllers 中
Vasucd is right, put LoginSinUpVC in NavigationController’s viewControllers first
——————编辑——————-
——————Edited—————-
如错误所示，这是因为您初始化了一个在 NavigationController 的 viewControllers 中不存在的新 viewController
As error indicates, this is because you init a new viewController that dose not exist in NavigationController's viewControllers
let vc = storyboard?.instantiateViewController(identifier: "LoginSignUpVC") as? LoginSignUpVC
解决问题，尝试在navigationController的viewControllers中找到LoginSignUpVC
to solve the problem, try to find LoginSignUpVC in navigationController's viewControllers
for vc in navigationController.viewControllers {
if let loginSignUpVC = vc as? LoginSignUpVC {
navigationController?.popToViewController(loginSignUpVC, animated: true)
}
}
这篇关于试图弹出一个不存在的视图控制器 swift 5.1 Xcode iOS的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！