无法使用Swift在Xcode中使用Parse 1.7.2和Facebook SDK 4.1创建新用户

我已经将我的应用程序链接到Facebook SDK和Parse，但是现在我试图将Facebook的登录信息与Parse集成在一起，但仍然遇到问题。我当前的问题是该应用程序正在运行，但是当我按FBSDKLoginButton时，它将转到safari并询问权限（应按要求进行），但是当按下okay时，它只是返回到该应用程序的登录屏幕，就像什么也没有发生一样，并且没有不能对应用程序的其余部分执行搜索。我还检查了Parse，它没有创建新的PFUser。我将在下面的LoginViewController中发布我认为可能相关的代码（这意味着该代码将缺少诸如viewDidLoad之类的部分，因为其中没有任何内容会影响登录过程）：

import UIKit
import Parse
import FBSDKCoreKit
import FBSDKLoginKit

protocol LoginViewControllerDelegate {
    func onRegister(loginViewController : LoginViewController)
    func onFacebookLogin(loginViewController : LoginViewController)
    func onLogin(loginViewController : LoginViewController)
}

class LoginViewController: UIViewController {

@IBAction func onFacebookLogin(sender: AnyObject?) {

    // Set permissions required from the facebook user account
    let permissions = [ "user_about_me", "user_relationships", "user_location", "user_birthday", "public_profile", "user_friends", "user_email", "user_gender"]

    // Login PFUser using Facebook
    PFFacebookUtils.logInInBackgroundWithReadPermissions(permissions, block: {
        (user: PFUser?, error: NSError?) -> Void in
        if let user = user {
            if user.isNew {
                println("User signed up and logged in through Facebook!")
                self.loadData()
                self.performSegueWithIdentifier("loggedIn", sender: self)
            } else {
                println("User logged in through Facebook!")
                self.performSegueWithIdentifier("loggedIn", sender: self)
            }
            if self.delegate != nil {
                self.delegate!.onFacebookLogin(self)
            }
        } else {
            println("Uh oh. The user cancelled the Facebook login.")
        }
    })
}

func loadData(){
    let request:FBSDKGraphRequest = FBSDKGraphRequest()
    request.startWithCompletionHandler { (connection:FBSDKGraphRequestConnection!, result:AnyObject!, error:NSError!) -> Void in
        if error == nil{
            if let dict = result as? Dictionary<String, AnyObject>{
                let name:String = dict["first_name"] as AnyObject? as! String
                let facebookID:String = dict["id"] as AnyObject? as! String
                let email:String = dict["email"] as AnyObject? as! String
                let birthday:String = dict["birthday"] as AnyObject? as! String
                let gender:String = dict["gender"] as AnyObject? as! String

                let hostCount:Int = 0
                let attendCount:Int = 0

                let pictureURL = "https://graph.facebook.com/\(facebookID)/picture?type=large&return_ssl_resources=1"

                var URLRequest = NSURL(string: pictureURL)
                var URLRequestNeeded = NSURLRequest(URL: URLRequest!)


                NSURLConnection.sendAsynchronousRequest(URLRequestNeeded, queue: NSOperationQueue.mainQueue(), completionHandler: {(response: NSURLResponse!,data: NSData!, error: NSError!) -> Void in
                    if error == nil {
                        var picture = PFFile(data: data)
                        PFUser.currentUser()!.setObject(picture, forKey: "profilePicture")
                        PFUser.currentUser()!.saveInBackground()
                    }
                    else {
                        println("Error: \(error.localizedDescription)")
                    }
                })
                PFUser.currentUser()!.setValue(name, forKey: "name")
                PFUser.currentUser()!.setValue(email, forKey: "email")
                PFUser.currentUser()!.setValue(birthday, forKey: "birthday")
                PFUser.currentUser()!.setValue(gender, forKey: "gender")
                PFUser.currentUser()!.setValue(hostCount, forKey: "hostCount")
                PFUser.currentUser()!.saveInBackground()
            }
        }
    }
}
}