Question

我目前正在制作一个应用程序，它已经在项目中实施了Google登录，而且我不确定为什么应用程序没有在InitialViewController场景上启动。它不是从最初的场景开始，而是从我的登录页面开始。我想这可能会发生，因为我设置它以便ViewController.swift文件与Login页面相关联，而不是与初始启动页面相关联。

以下是我的AppDelegate的代码：

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:.
    }


}

和ViewController

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.
    }


}

此处还有我的main.storyboard的屏幕截图：

Main.Storyboard Screenshot

Answer 1

应用不是从故事板中指定的InitialViewController开始的原因是window!.rootViewController = tabBarVC。通过设置rootViewController上的window，您实际上会覆盖storyboard上设置的规范。因此它被忽略了。

如果您想在屏幕截图中显示带有ViewController标签的TheOracle，则应该为ViewController提供一个标识符。让我们称之为OnboardingViewController。

然后你应该更新这个：

if let tabBarVC = sb.instantiateViewController(withIdentifier: "LogInViewController") as? ViewController {
    window!.rootViewController = tabBarVC
}

到

if let tabBarVC = sb.instantiateViewController(withIdentifier: "OnboardingViewController") as? ViewController {
    window!.rootViewController = tabBarVC
}

Swift App无法从Initial ViewController场景开始

1 个答案: