Swift Facebook 登录后项目无法正确继续

Swift project not segue-ing properly after Facebook login

初始ViewController,LoginViewController.swift:

import UIKit

class LoginViewController: UIViewController, FBSDKLoginButtonDelegate {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do view setup here.

        if (FBSDKAccessToken.currentAccessToken() != nil)
        {
            // User is already logged in, do work such as go to next view controller.
            performSegueWithIdentifier("loginSegue", sender: nil)
            print("segued due to login")
        }
        else
        {
            let loginView : FBSDKLoginButton = FBSDKLoginButton()
            self.view.addSubview(loginView)
            loginView.center = self.view.center
            loginView.readPermissions = ["public_profile", "user_friends"]
            loginView.delegate = self
        }
    }

    func loginButton(loginButton: FBSDKLoginButton!, didCompleteWithResult result: FBSDKLoginManagerLoginResult!, error: NSError!) {
        print("User Logged In")
        if ((error) != nil)
        {
            // Process error
        }
        else if result.isCancelled {
            // Handle cancellations
        }
        else {
            // If you ask for multiple permissions at once, you
            // should check if specific permissions missing
            performSegueWithIdentifier("loginSegue", sender: nil)
            /*
            if result.grantedPermissions.contains("email")
            {
                // Do work
            }
            */
        }
    }

    func loginButtonDidLogOut(loginButton: FBSDKLoginButton!) {
        print("User Logged Out")
    }

}

"segued due to login" 每次启动应用程序时都会打印到终端,因此显然已到达 if 语句以及 performSegueWithIdentifier() 行。然而,由于 LoginViewController 停留在屏幕上并且下一个 ViewController 没有显示,因此实际上并没有执行 segue。我也尝试添加行:

    performSegueWithIdentifier("loginSegue", sender: nil)

在我知道程序到达的其​​他几个位置,比如 super.viewDidLoad() 之后。所以,问题似乎是特定于 segue 而问题似乎与 Facebook 的登录无关。

我附上了带有 segue 属性的故事板截图:

如果需要,我可以包含任何其他文件。我还怀疑它可能是一个与 类似的错误类型我已经尝试删除我所有 ViewController 中 UITextViews 中的占位符,但这并没有解决问题。

好的,这就是您的 application:didFinishLaunching:withOptions 的样子。

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
    // Override point for customization after application launch.
    FBSDKApplicationDelegate.sharedInstance().application(application, didFinishLaunchingWithOptions: launchOptions)

    let mainStoryboard = UIStoryboard.init(name: "Main", bundle: nil)
    self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
    var initialViewController: UIViewController

    if(FBSDKAccessToken.currentAccessToken() != nil){
        let vc = mainStoryboard.instantiateViewControllerWithIdentifier("someOtherViewController") as! SomeOtherViewController
        initialViewController = vc
    }else{
        initialViewController = mainStoryboard.instantiateViewControllerWithIdentifier("loginViewController")
    }

    self.window?.rootViewController = initialViewController

    self.window?.makeKeyAndVisible()

    return true
}