ios - Swift:使用 Firebase 自动登录用户

Question

如果用户已经签名，我想自动登录他，然后直接转到主视图，但代码运行了两次，您可以看到转换，而不是刚刚显示的 View 。我该如何解决？

AppDelegate.swift

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
    // Override point for customization after application launch.slideMenuController
    FIRApp.configure()
    FIRAuth.auth()?.addAuthStateDidChangeListener {
        auth, user in
        if user != nil {
            // User is signed in.
            print("Automatic Sign In: \(user?.email)")

            let storyboard = UIStoryboard(name: "Main", bundle: nil)
            let initialViewController = storyboard.instantiateViewControllerWithIdentifier("EmployeeRevealViewController")
            self.window!.rootViewController = initialViewController

        } else {
            // No user is signed in.
        }
    }

    return true
}

日志

2016-06-06 01:00:55.585 Untitled[13009:6258910] Configuring the default app.
2016-06-06 01:00:55.657 Untitled[13009:] <FIRAnalytics/INFO> Firebase Analytics v.3200000 started
2016-06-06 01:00:55.666 Untitled[13009:] <FIRAnalytics/INFO> To enable debug logging set the following application argument: -FIRAnalyticsDebugEnabled
2016-06-06 01:00:55.714 Untitled[13009:6258910] Firebase Crash Reporting: Successfully enabled
2016-06-06 01:00:55.739: <FIRInstanceID/WARNING> FIRInstanceID AppDelegate proxy enabled, will swizzle app delegate remote notification handlers. To disable add "FirebaseAppDelegateProxyEnabled" to your Info.plist and set it to NO
2016-06-06 01:00:55.739: <FIRInstanceID/WARNING> Failed to fetch APNS token Error Domain=com.firebase.iid Code=1001 "(null)"
2016-06-06 01:00:55.760: <FIRMessaging/INFO> FIRMessaging library version 1.1.0
2016-06-06 01:00:55.781: <FIRMessaging/WARNING> FIRMessaging AppDelegate proxy enabled, will swizzle app delegate remote notification receiver handlers. Add "FirebaseAppDelegateProxyEnabled" to your Info.plist and set it to NO
2016-06-06 01:00:55.788 Untitled[13009:] <FIRAnalytics/INFO> Successfully created Firebase Analytics App Delegate Proxy automatically. To disable the proxy, set the flag FirebaseAppDelegateProxyEnabled to NO in the Info.plist
Automatic Sign In: Optional("mohamed.mohd@hotmail.com")
2016-06-06 01:00:56.759: <FIRInstanceID/WARNING> APNS Environment in profile: development
Automatic Sign In: Optional("mohamed.mohd@hotmail.com")
2016-06-06 01:00:57.811 Untitled[13009:] <FIRAnalytics/INFO> Firebase Analytics enabled

Answer 1

尝试:

if let alreadySignedIn = FIRAuth.auth()?.currentUser {
    // segue to main view controller
} else {
    // sign in
}