Question

我正在尝试返回结果并能够从此函数访问结果数组。一切都在函数中工作，但是我无法从闭包外部返回任何内容或访问结果或在函数内创建的任何变量。我想从闭包外部访问result.valueForKey（＆＃34; id＆＃34;）。我怎么能这样做？

class ViewController: UIViewController, FBSDKLoginButtonDelegate {

var facebookid: NSString = ""
var username: NSString = ""
var userEmail:NSString = ""

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    if (FBSDKAccessToken.currentAccessToken() == nil)
    {
        let loginView : FBSDKLoginButton = FBSDKLoginButton()
        self.view.addSubview(loginView)
        loginView.center = self.view.center
        loginView.readPermissions = ["public_profile"]
        loginView.delegate = self

    } else {

        returnUserData()

        println(facebookid)  // This doesn't work

    }
}



    func returnUserData()
{

    let graphRequest : FBSDKGraphRequest = FBSDKGraphRequest(graphPath: "me", parameters: nil)
    graphRequest.startWithCompletionHandler({ (connection, result, error) -> Void in

        if ((error) != nil)
        {
            // Process error
            println("Error: \(error)")
        }
        else
        {

            self.facebookid = result.valueForKey("id") as NSString!
            self.username = result.valueForKey("name") as NSString!
            self.userEmail = result.valueForKey("email") as NSString!
            println(result) // This works


        }
    })
}

编辑：我确实根据下面的2个答案更改了代码但仍然无法在viewDidLoad闭包上获得任何数据返回。 * println（facebookid）在ViewDidLoad中没有返回任何内容，而它在函数闭包内部。

Answer 1

您正在闭包内创建变量，这意味着它们只能在内部访问。

您需要在课程顶部的函数外部创建变量。

例如

 class YourClassName {

      var facebookid
      var username
      var userEmail


 func returnUserData()
 {
     let graphRequest : FBSDKGraphRequest = FBSDKGraphRequest(graphPath:  "me", parameters: nil)
     graphRequest.startWithCompletionHandler({ (connection, result, error) -> Void in

    if ((error) != nil)
    {
        // Process error
        println("Error: \(error)")
    }
    else
    {
        self.facebookid = result.valueForKey("id") as? String
        self.userName = result.valueForKey("name") as? String
        self.userEmail = result.valueForKey("email") as? String

    }
  })
 }
}

Answer 2

func loginButton(_ loginButton: FBSDKLoginButton!, didCompleteWith result: FBSDKLoginManagerLoginResult!, error: Error!) {       
        if error != nil {
            print(error.localizedDescription)
            return
        }


                print("user loged in with facebook")
                if((FBSDKAccessToken.current()) != nil) {
                    FBSDKGraphRequest(graphPath: "me", parameters: ["fields": "id, name, first_name, last_name, email, age_range, link, gender, locale, timezone, updated_time, verified"]).start(completionHandler: { (connection, result, error) -> Void in
                        if (error == nil){
                            print(result!)
                            print("Token: \((FBSDKAccessToken.current().tokenString)!)")
                            print("Token Expiration Date: \((FBSDKAccessToken.current().expirationDate)!)")
                        }
                    })
                }

    }

从函数返回数据（Swift）

2 个答案: