注銷Google登錄並返回到登錄頁面：Swift / Xcode

Question

我已經成功為我的應用創建了Google登錄，該應用可以正常運行，因此，如果用戶登錄，則該用戶將被帶到選項卡控制器。

現在，我在選項卡控制器中的兩個項目上都有退出按鈕，以便用戶可以退出。 我想知道如何做到這一點，以便用戶可以單擊“退出”按鈕，這將使他們成功在應用程序中退出Google的登錄，然后將用戶返回“登錄”頁面。

這是我的Main.storyboard的屏幕截圖：

MainStoryboard屏幕截圖

這是我的AppDelegate文件的代碼：

AppDelegate.swift

import UIKit
import Firebase
import GoogleSignIn

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate, GIDSignInDelegate {

    var window: UIWindow?


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

        FIRApp.configure()

        GIDSignIn.sharedInstance().clientID = FIRApp.defaultApp()?.options.clientID
        GIDSignIn.sharedInstance().delegate = self

        if GIDSignIn.sharedInstance().hasAuthInKeychain() {
            print("User has been successfully signed in with Google")
            let sb = UIStoryboard(name: "Main", bundle: nil)
            if let tabBarVC = sb.instantiateViewController(withIdentifier: "TabController") as? UITabBarController {
                window!.rootViewController = tabBarVC
            }
        } else {
            print("User has failed in signing in with Google")
            let sb = UIStoryboard(name: "Main", bundle: nil)
            if let tabBarVC = sb.instantiateViewController(withIdentifier: "LogInViewController") as? ViewController {
                window!.rootViewController = tabBarVC
            }
        }

        return true
    }



    func sign(_ signIn: GIDSignIn!, didSignInFor user: GIDGoogleUser!, withError error: Error!) {
        if let err = error {
            print("Failed to log into Google: ", err)
            return
        }

        print("Successfully logged into Google", user)

        guard let idToken = user.authentication.idToken else { return }
        guard let accessToken = user.authentication.accessToken else { return }
        let credentials = FIRGoogleAuthProvider.credential(withIDToken: idToken, accessToken: accessToken)

        FIRAuth.auth()?.signIn(with: credentials, completion: { (user, error) in
            if let err = error {
                print("Failed to create a Firebase User with Google account: ", err)
                return
            }

            guard let uid = user?.uid else { return }
            print("Successfully logged into Firebase with Google", uid)
        })
    }


    func application(_ app: UIApplication, open url: URL, options: [UIApplicationOpenURLOptionsKey : Any] = [:]) -> Bool {



        GIDSignIn.sharedInstance().handle(url,
                                          sourceApplication: options[UIApplicationOpenURLOptionsKey.sourceApplication] as! String!,
                                          annotation: options[UIApplicationOpenURLOptionsKey.annotation])

        return true
    }

    func applicationWillResignActive(_ application: UIApplication) {
        // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
        // Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
    }

    func applicationDidEnterBackground(_ application: UIApplication) {
        // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
        // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
    }

    func applicationWillEnterForeground(_ application: UIApplication) {
        // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
    }

    func applicationDidBecomeActive(_ application: UIApplication) {
        // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
    }

    func applicationWillTerminate(_ application: UIApplication) {
        // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
    }


}

如果需要，還可以添加ViewController.swift文件：

import UIKit
import Firebase
import GoogleSignIn

class ViewController: UIViewController, GIDSignInUIDelegate {

    override func viewDidLoad() {
        super.viewDidLoad()


        setupGoogleButtons()
    }

    fileprivate func setupGoogleButtons() {
        //add google sign in button
        let googleButton = GIDSignInButton()
        googleButton.frame = CGRect(x: 16, y: 116 + 66, width: view.frame.width - 32, height: 50)
        view.addSubview(googleButton)
        //custom google button
        let customButton = UIButton(type: .system)
        customButton.frame = CGRect(x: 16, y: 116 + 66 + 66, width: view.frame.width - 32, height: 50)
        customButton.backgroundColor = .orange
        customButton.setTitle("Custom Google Sign In", for: .normal)
        customButton.addTarget(self, action: #selector(handleCustomGoogleSign), for: .touchUpInside)
        customButton.setTitleColor(.white, for: .normal)
        customButton.titleLabel?.font = UIFont.boldSystemFont(ofSize: 14)
        view.addSubview(customButton)

        GIDSignIn.sharedInstance().uiDelegate = self
    }

    func handleCustomGoogleSign() {
        GIDSignIn.sharedInstance().signIn()
    }

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


}

Answer 1

很容易做到：

注銷action ，只需將window的rootvc設置為logint vc

window!.rootViewController = login vc