Sharing data between multiple view controllers without segue (Swift 3)

Question

I'm doing a QR code scanner quiz app where users must get a score of 10 from doing 10 questions. After a user the 1st qn, the score will plus 1 and it will revert them back to the qr scanner page where they must scan the QR code for the next qn. The problem is the passing of the score data. Is there a way to do it without segue?

This is my qn1controller

import UIKit

class Quiz1Controller: UIViewController {

    @IBOutlet var question: UILabel!
    @IBOutlet var button1: UIButton!
    @IBOutlet var button2: UIButton!
    @IBOutlet var button3: UIButton!
    @IBOutlet var button4: UIButton!
    @IBOutlet var LabelEnd: UILabel!
    @IBOutlet var scorelabel: UILabel!
    var score = Int()
    var CorrectAnswer = String()

    override func viewDidLoad() {
        super.viewDidLoad()

        RandomQuestions()
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func RandomQuestions(){

        var RandomNumber = arc4random() % 1
        RandomNumber += 1

        switch(RandomNumber){
        case 1:
            question.text = "Who is the current Deputy Chairman of People's Association?"
            button1.setTitle("Lee Hsien Loong", for: .normal)
            button2.setTitle("Chan Chun Sing", for: .normal)
            button3.setTitle("Goh Chok Tong", for: .normal)
            button4.setTitle("Goh Khen Swee", for: .normal)
            CorrectAnswer = "2"
            Hide()
            break
        default:
            break
        }
    }

    func Hide(){
        LabelEnd.isHidden = true
    }
    func UnHide(){
        LabelEnd.isHidden = false
    }

    @IBAction func Button1(_ sender: Any) {
        UnHide()

        if (CorrectAnswer == "1"){
            self.performSegue(withIdentifier: "correct", sender: self)
        }
        else {
            LabelEnd.text = "Incorrect Answer! Try again"
        }
    }

    @IBAction func Button2(_ sender: Any) {
        UnHide()

        if (CorrectAnswer == "2"){
            score = score + 1
            scorelabel.text = "Score:\(score)"
            self.performSegue(withIdentifier: "correct", sender: self)            
        }
        else {
            LabelEnd.text = "Incorrect Answer! Try again"
        }
    }

    @IBAction func Button3(_ sender: Any) {
        UnHide()

        if (CorrectAnswer == "3"){
            self.performSegue(withIdentifier: "correct", sender: self)
        }
        else {
            LabelEnd.text = "Incorrect Answer! Try again"
        }
    }

    @IBAction func Button4(_ sender: Any) {
        UnHide()

        if (CorrectAnswer == "4"){
            self.performSegue(withIdentifier: "correct", sender: self)
        }
        else {
            LabelEnd.text = "Incorrect Answer! Try again"
        }
    }

}

And this is my qn2 controller

import UIKit

class Quiz2Controller: UIViewController {

    @IBOutlet var question: UILabel!
    @IBOutlet var button1: UIButton!
    @IBOutlet var button2: UIButton!
    @IBOutlet var button3: UIButton!
    @IBOutlet var button4: UIButton!
    @IBOutlet var LabelEnd: UILabel!
    @IBOutlet var scorelabel: UILabel!
    var score = Int()
    var CorrectAnswer = String()

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.
        RandomQuestions()
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
            // Dispose of any resources that can be recreated.
        }

    func RandomQuestions(){

        var RandomNumber = arc4random() % 1
        RandomNumber += 1

        switch(RandomNumber){
        case 1:
            question.text = "Who is the founder of People's Association?"
            button1.setTitle("Lee Hsien Loong", for: .normal)
            button2.setTitle("Lee Kuan Yew", for: .normal)
            button3.setTitle("Goh Chok Tong", for: .normal)
            button4.setTitle("Goh Khen Swee", for: .normal)
            CorrectAnswer = "1"
            Hide()
            break
        default:
            break
        }
    }

    func Hide(){
        LabelEnd.isHidden = true
    }
    func UnHide(){
        LabelEnd.isHidden = false
    }

    @IBAction func Button1(_ sender: Any) {
        UnHide()

        if (CorrectAnswer == "1"){
            score = score + 1
            scorelabel.text = "Score:\(score)"
            self.performSegue(withIdentifier: "correct", sender: self)
        }
        else {
            LabelEnd.text = "Incorrect Answer! Try again"
        }
    }

    @IBAction func Button2(_ sender: Any) {
        UnHide()

        if (CorrectAnswer == "2"){
            self.performSegue(withIdentifier: "correct", sender: self)
        }
        else {
            LabelEnd.text = "Incorrect Answer! Try again"
        }
    }

    @IBAction func Button3(_ sender: Any) {
        UnHide()

        if (CorrectAnswer == "3"){
            self.performSegue(withIdentifier: "correct", sender: self)
        }
        else {
            LabelEnd.text = "Incorrect Answer! Try again"
        }
    }

    @IBAction func Button4(_ sender: Any) {
        UnHide()

        if (CorrectAnswer == "4"){
            self.performSegue(withIdentifier: "correct", sender: self)
        }
        else {
            LabelEnd.text = "Incorrect Answer! Try again"
        }
    }

}

Story Board :

Consider to present the scanner view controller modally. Then you get a reference to the presenting controller and can pass the data back. — vadian, Jul 31 '17 at 04:29
If you need pass data you can use delegate or notification. If you need share data you can use singleton. — Dimuth, Jul 31 '17 at 04:31
You can use delegate method & NSUserDefaults to share you data whole in app. — Shahbaz Akram, Jul 31 '17 at 05:54
You can use delegate method & NSUserDefaults to share you data whole in app. — Shahbaz Akram, Jul 31 '17 at 05:55
@MianShahbazAkram could u teach me on how to do that? i'm very new to swift — Kinja, Aug 01 '17 at 08:27
Yes you can save every answer data into nsuserdefault against specific question key and then get it anywhere in app. — Shahbaz Akram, Aug 01 '17 at 09:42
@MianShahbazAkram could you show me some steps/tutorial on how to do it? — Kinja, Aug 01 '17 at 13:07
http://www.ios-blog.co.uk/tutorials/objective-c/storing-data-with-nsuserdefaults/ — Shahbaz Akram, Aug 02 '17 at 06:58
https://www.hackingwithswift.com/read/12/2/reading-and-writing-basics-userdefaults — Shahbaz Akram, Aug 02 '17 at 06:58

score 0 · Answer 1 · answered Jul 31 '17 at 05:11

Delete Seague and do it like as follow. Assume you want to share NSMutableDictionary.

Just take a variable as type you want to share with viewController.

For Exa. you want to share data with ShareViewController then take a variable like

var Dict_data = NSMutableDictionary()

Now Where you want to navigate, just do like Assume It's your ShareViewController. Remember dont forget to give identifier of ShareViewController into StoryBoard.

    let PV = self.storyboard?.instantiateViewController(withIdentifier: "ShareViewController") as! ShareViewController
    PV.data = dict_share_date 
    self.navigationController?.pushViewController(PV, animated: true)

Here dict_share_data is your NSMutableDictionry. You can take any type but remember both side types must same. or you can do type casting.

luckyShubhra · Answer 2 · 2017-07-31T09:46:21.970

0

You can use AppDelegate to share data between multiple Viewcontrollers. You can always save ,update and retrieve data defined in AppDelegate of your App. Here is my previous ans to use it efficiently to use Appdelegate.Do let me know if you need Swift version .

In your AppDelegate define your variable as

class AppDelegate: UIResponder, UIApplicationDelegate {
  var window: UIWindow?
  var points : String? // Declare your object
  .... other methods
}
//You can access the property to save and retrieve your file. You can save 
let app = UIApplication.shared.delegate as! AppDelegate
app.points = "yourString"

 Yo can read properties from any viewcontroller as per your requirement as 

let app = UIApplication.shared.delegate as! AppDelegate
let points = app.points?

You can also use NSNotificationCenter to share data in multiple viewcontoller. Do let me know if you have queries regrading implementing the same.

If you need to pass data from one viewcontroller to another while navigation you can also use instantiation of viewcontoller using storyboard id as @Jeetendra explains in his ans.

edited Jul 31 '17 at 09:46

answered Jul 31 '17 at 05:45

luckyShubhra

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Hi, i would really appreciate it if you could send a swift version or maybe even a step-by-step tutorial because i'm new to Swift/Xcode and this is for my major project. :( – Kinja Jul 31 '17 at 09:30
you need swift version for Appdelegate appraoch?? – luckyShubhra Jul 31 '17 at 09:32
Yes, and i think nsnotificationcenter will also work for mine but what do you mean by queries regrading implementing the same? – Kinja Jul 31 '17 at 09:42
I have edited my ans to include Swift version.By that above comment I mean ,if any information regarding implementation of NSNotification Centre is required I would help you. – luckyShubhra Jul 31 '17 at 09:50
because my score is an int, so in the appdelegate am i supposed to put it as "var score : Int?" ? – Kinja Aug 01 '17 at 03:06
yepp you can declare score as Int. – luckyShubhra Aug 01 '17 at 03:22
so "let app = UIApplication.shared.delegate as! AppDelegate" "let score = app.score?" is supposed to be in my qn1controller and qn2controller right? – Kinja Aug 01 '17 at 03:28
yes. when you have acess you can use `let score = app.score?` when you have assign score `app.points = yourScore` – luckyShubhra Aug 01 '17 at 04:27
so what if my app suddenly crash/i close it, will my score data still remain the same? or reset to 0 again? – Kinja Aug 01 '17 at 05:11
it will reset to zero. If you need persistent data you can use NSUserDefaults of Core Data for the same. – luckyShubhra Aug 01 '17 at 05:19
do u know how to do that? because i practically have 0 knowledge on swift :( – Kinja Aug 01 '17 at 05:50
check this link to save int in NSUserDefaults in Swift3. https://stackoverflow.com/questions/29930736/making-nsuserdefault-of-type-integer-in-swift – luckyShubhra Aug 01 '17 at 05:56
so am i right to say that NSUserDefaults also can help to share the score data between multiple controllers like appdelegate? – Kinja Aug 01 '17 at 06:19
NSUserDefaults is used only when persistent data is required. – luckyShubhra Aug 01 '17 at 07:39

Sharing data between multiple view controllers without segue (Swift 3)

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