如何將UITabBarController導航到ViewController？

Question

我里面有一個TabBarController ，我正在加載兩個ViewControllers 。

import UIKit

class TabBarViewController: UITabBarController {

    override func viewDidLoad() {
        super.viewDidLoad()

    }
}

圖片：

class AttendanceViewController: UIViewController,UIApplicationDelegate,
    UICollectionViewDelegateFlowLayout,UINavigationControllerDelegate,
    CLLocationManagerDelegate,UIImagePickerControllerDelegate {

    override func viewWillAppear(_ animated: Bool) {
    if  Auth.auth().currentUser?.uid == nil {
        //Below code is not working
        let vc = UIStoryboard.init(name: "Main", bundle: Bundle.main)
        .instantiateViewController(withIdentifier: "LoginViewController") as? LoginViewController
        self.navigationController?.pushViewController(vc!, animated: true)
        print("user is not login in redirect to login page")
        return
    }else{
        print("User Successfully loginedin")
    }
}

}

注意：我有兩個像AttendanceViewController和TaskViewController這樣的視圖控制器，我想檢查用戶是否未登錄，然后我想重定向到我的LoginViewController，我嘗試了上面的代碼，但它不起作用

Answer 1

目前的UIViewController

如果您的ViewController嵌入在UINavigationController ，則您編寫的代碼將起作用。 因此，除了顯示不存在的UINavigationController中的UIViewController ，您還可以顯示LoginViewController 。 因此，替換為：

let vc = UIStoryboard.init(name: "Main", bundle: Bundle.main)
.instantiateViewController(withIdentifier: "LoginViewController") as? LoginViewController
self.navigationController?.pushViewController(vc!, animated: true)

與

let vc = UIStoryboard.init(name: "Main", bundle: Bundle.main)
.instantiateViewController(withIdentifier: "LoginViewController") as? LoginViewController
present(vc!, animated: true, completion: nil)  

嵌入在UINavigationController中

或者，您可以將UIViewController嵌入UINavigationController並設置帶有標識符的segue，然后對LoginViewController執行此segue。

7.進行檢查

performSegue(withIdentifier: "YourIdentifier", sender: self)

Answer 2

嘿，我剛剛創建了一個示例，它將幫助您：-

我只是使用userdefaults保存loginState

這是：-

1）。 TaskViewController

我剛剛在其中創建了一個退出按鈕

import UIKit

class TaskViewController: UIViewController {


@IBOutlet weak var signOutButton: UIButton!

override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view.
}

override func viewDidLayoutSubviews() {
    signOutButton.layer.cornerRadius = signOutButton.layer.frame.height/2
}



@IBAction func signOutButtonTapped(_ sender: Any) {

    UserDefaults.standard.set(false, forKey: "isUserLoggedIn")  // here I remove the boolean value
    UserDefaults.standard.synchronize()
    let storyBoard = UIStoryboard(name: "Login", bundle: nil)
    let loginVc = storyBoard.instantiateViewController(withIdentifier: "LoginViewController") as! LoginViewController
    let rootVc = UINavigationController(rootViewController: loginVc)
    UIApplication.shared.keyWindow?.rootViewController = rootVc

}



}

2）。 AttendanceViewController-我沒有在其中創建任何內容

import UIKit

class AttendanceViewController: UIViewController {

override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view.
}


}

這兩個控制器都在TabBarController內部，后者是HomeController

import UIKit

class HomeController: UITabBarController {

override func viewDidLoad() {
    super.viewDidLoad()


}

}

我在Main.storyboard文件中創建了它：

並在login.storyboard文件中創建LoginViewController

LoginViewController：-這里保存了loginState

import UIKit

class LoginViewController: UIViewController {

@IBOutlet weak var loginButton: UIButton!


override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view.
}

override func viewDidLayoutSubviews() {
    loginButton.layer.cornerRadius = loginButton.layer.frame.height/2
}


@IBAction func loginButtonTapped(_ sender: Any) {

    let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
    let viewController = mainStoryboard.instantiateViewController(withIdentifier: "HomeController") as! HomeController
    UserDefaults.standard.set(true, forKey: "isUserLoggedIn")
    UserDefaults.standard.synchronize()
    UIApplication.shared.keyWindow?.rootViewController = viewController

}

}

最后在Appdelegate.swift檢查didFinishLaunchingWithOptions的loginState像這樣：

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

    let userLoginStatus = UserDefaults.standard.bool(forKey: "isUserLoggedIn")
    print(userLoginStatus)

    if(userLoginStatus)
    {
        let mainStoryBoard = UIStoryboard(name: "Main", bundle: nil)
        let centerVC = mainStoryBoard.instantiateViewController(withIdentifier: "HomeController") as! HomeController
        window!.rootViewController = centerVC
        window!.makeKeyAndVisible()
    } else {

        let mainStoryBoard = UIStoryboard(name: "Login", bundle: nil)
        let centerVC = mainStoryBoard.instantiateViewController(withIdentifier: "LoginViewController") as! LoginViewController
        window!.rootViewController = centerVC
        window!.makeKeyAndVisible()
    }

    return true
}

這是完整的項目-https://www.dropbox.com/s/3d34raovyx6orda/saveLogin.zip?dl=0

Answer 3

我認為您想在appDelegate進行檢查。 如今，我還與UITabbarcontroller一起使用。我建議設置一個標簽（使用userDefaults）來檢查用戶是否登錄。 我的代碼是

class AppDelegate: UIResponder, UIApplicationDelegate , UITabBarControllerDelegate , GIDSignInDelegate{

    var window: UIWindow?

    var userCurrentLocation : CLLocation?
    var mapView : GMSMapView?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {

        if UserDefaults.standard.value(forKey: "LoginStatus")as? String == "1"
        {
            let storyBoard = UIStoryboard(name: "Main", bundle: nil)
            let initailVC = storyBoard.instantiateViewController(withIdentifier: "tabBar")
            let navVC = UINavigationController(rootViewController: initailVC)
            self.window?.rootViewController = navVC
        }

        return true
    }

我正在使用此代碼來檢查用戶是否正在登錄，它將重定向到TabBarController ，否則將保留在LoginVC中。

Answer 4

• 將您的UITabBarController嵌入到UINavigationController

  UINavigationController(rootViewController: UITabBarController(nibName: "TabBarNibName", bundle: Bundle.main))

• 只需從TabBarController的導航控制器中推送

  tabbarcontroller.navigationController?.pushViewController(vc!, animated: true)