bekomme ein Array von einem Web-Service in eine Pickerview

Question

Ich habe derzeit einen Webservice-Link, der eine Frage und eine Reihe von Antworten hat. Ich brauche meine Pickerview, um diese Antworten zu laden, aber dies lädt das Array überhaupt nicht oder irgendwelche Daten. Der Name des Arrays „Antworten“ genannt

class QuestionsViewController: UIViewController, UIPickerViewDelegate { 

@IBOutlet weak var usernamelabel: UILabel! //sets username label 
@IBOutlet weak var Next: UIButton! //next button 
@IBOutlet weak var itemLabel: UILabel! //item user has selected 
@IBOutlet weak var Question: UILabel! //sets question label 
@IBOutlet weak var pickerview: UIPickerView! //sets picker view 

public var totalQuestions: Int = 0 //sets total question to 0 
public var currentQuestion = 0 //sets current question to 0 
public var totalCorrect: Int = 0 //sets totalcorrect to 0 
var itemSelected: String = "" //item selected 
var LabelText = String() 
//let Exam = QuestionList() //uses the questions class for instances 
//var Questions = QuestionList.getDummyQuestions() 
@IBOutlet weak var share: UIButton! 


//var listQuestions = [[String: AnyObject]]() 

var listQuestions = [[String: AnyObject]]() 
var titles: [String] = [] 



var quiz = QuestionList() 

var ref: FIRDatabaseReference! 
var refHandle: UInt! 


override func viewDidLoad() { 


    super.viewDidLoad() //when the app is loaded 
    //authPlayer() 

    let url:String = "https://api.mlab.com/api/1/databases/quiz/collections/question?apiKey=NT28RNl6jX3Ys0x5GJZ6mMSRQEcb_6KA" 

    let urlRequest = URL(string: url) 

    URLSession.shared.dataTask(with: urlRequest!, completionHandler: { 
     (data, response, error) in 
     if(error != nil){ 
      print(error.debugDescription) 
     } 
     else{ 
      do{ 
       self.listQuestions = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as! [[String:AnyObject]] 

       //self.tableview.reloadData() 

      }catch let error as NSError{ 
       print(error) 
      } 
     } 
    }).resume() 


    share.isHidden = true 

    ref = FIRDatabase.database().reference() //reference 
    refHandle = ref.child("Questions").observe(.value, with: { (snapshot)in 
     let dataDict = snapshot.value as! [String: AnyObject] 
     print (dataDict) 
    }) 
    usernamelabel.text = LabelText //username 

    pickerview.delegate = self 

    itemLabel.text = "" //loads the item label of whats selected 
    totalQuestions = QuestionList.getDummyQuestions().count 
    itemSelected = QuestionList.getDummyQuestions()[currentQuestion].answers[currentQuestion] //initially when loaded first item is selected 
    itemSelected = QuestionList.getDummyQuestions()[currentQuestion].answers[1] 
    //Question.text = QuestionList.getDummyQuestions()[currentQuestion].quest 
    //Question.text = Exam.quiz[currentQuestion][0] //first element in first row of array 
    Question.text = QuestionList.getDummyQuestions()[currentQuestion].quest 
    //cell.EventImgView.image = event["Image"] as? UIImage 

    //Question.text = q["Title"] as? String 




} 


func numberOfComponents(in pickerView: UIPickerView) -> Int { 

    return 1 //return one component from the picker 
} 

func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int{ 
    //return QuestionList.getDummyQuestions()[currentQuestion].answers.count 
    //let q = listQuestions[row] 
    //return listQuestions[currentQuestion].count[row] 
    //return listQuestions.count[row] 
    return listQuestions.count 
} 

func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String?{ 


    //return QuestionList.getDummyQuestions()[currentQuestion].answers[row] 
    let q = listQuestions[row] 
    return q["Answers"] as? String 

    //cell.EventImgView.image = event["Image"] as? UIImage 

} 

func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int){ 

    itemSelected = QuestionList.getDummyQuestions()[currentQuestion].answers[row] 

} 

@IBAction func btnShareClicked(_ sender: UIButton) { 

    if SLComposeViewController.isAvailable(forServiceType: SLServiceTypeFacebook) { 

     let fbShare:SLComposeViewController = SLComposeViewController(forServiceType:SLServiceTypeFacebook) 
     //fbShare.setInitialText("You Scored on the IT Quiz:" + itemLabel.text!) 
     fbShare.setInitialText("You Scored " + itemLabel.text! + " on the IT Quiz") 
     self.present(fbShare, animated:true, completion:nil) 

    } else { 
     let alert = UIAlertController(title: "Account", message: "Please login to Facebook", 
     preferredStyle: UIAlertControllerStyle.alert) 

     alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler:nil)) 
     self.present(alert, animated: true, completion: nil) 

    } 

} 

func addGC(_ sender: Any) { 


} 

/*func authPlayer() { 
    let localPlayer = GKLocalPlayer.localPlayer() 
    localPlayer.authenticateHandler = { 
     (view, error) in 

     if view != nil { 
      self.present(view!, animated:true, completion: nil) 
     } 
     else { 
      print(GKLocalPlayer.localPlayer().isAuthenticated) 
     } 
    } 

} 

func saveHighScore(score: String) { 
    if GKLocalPlayer.localPlayer().isAuthenticated { 

    } 
}*/ 





@IBAction func NextAction(_ sender: Any){ 


    if (QuestionList.getDummyQuestions()[currentQuestion].isCorrectQuestion(itemSelected: itemSelected)) { 
     totalCorrect += 1 
     itemLabel.text = String(totalCorrect) + "/" + String(totalQuestions) 
    } 

    if(currentQuestion < totalQuestions - 1) { 
     pickerview.reloadAllComponents() 
     itemSelected = QuestionList.getDummyQuestions()[currentQuestion].answers[1] 
     Question.text = QuestionList.getDummyQuestions()[currentQuestion].quest 
     currentQuestion = currentQuestion + 1 //moves onto next question and increments 


    } else { 
     pickerview.isHidden = true 
     Question.text = "You have finished" 
     Next.isHidden = true 
     share.isHidden = false; 
    } 

} 

}

Answer 1

Die Picker Ansicht ist leer, wie Sie die Picker Ansicht nachladen muß, nachdem Sie die JSON-Antwort erhalten. So nach dieser Zeile

self.listQuestions = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as! [[String:AnyObject]] 

hinzufügen in

self.pickerview.reloadAllComponents() 

------- ------ EDIT

Der Grund, warum Sie etwas nicht sehen, ist, weil Ihr JSON Parsing ist falsch. Sie JSON gibt Antworten, Fragen & _id zurück. Deine listQuestions werden diese 3 Elemente sein. Was Sie tun müssen, ist das Array der Antworten zu extrahieren.

Wie gerade jetzt, Ihre

let q = listQuestions[row] 
return q["Answers"] as? String 

q tun würde für das Element ein Array [0], eine Zeichenfolge für das Element [1] und ein Wörterbuch für Element [2]

--- EDIT ---- Ok, wie ich schon sagte, Ihr zweites Problem ist, dass Sie nicht Ihre JSON im richtigen Format analysiert haben, so dass der Titel nicht angezeigt wird. Sie bereits erklärt, ein Titel Array so Ihren Code zu diesem

URLSession.shared.dataTask(with: urlRequest!, completionHandler: { 
     (data, response, error) in 
     if(error != nil){ 
      print(error.debugDescription) 
     } 
     else{ 
      do{ 
       self.listQuestions = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as! [[String:AnyObject]] 

       for elements in self.listQuestions { 
        for object in elements { 
         if object.key == "Answers" { 
          if let answers = object.value as? [String] { 
           self.titles = answers 
          } 
         } 
        } 
       } 
       self.pickerview.reloadAllComponents() 

      }catch let error as NSError{ 
       print(error) 
      } 
     } 
    }).resume() 

Dann

ändern offensichtlich Ihre Picker Ansicht Delegatmethoden zu

func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String?{ 
    return self.titles[row] 
} 

&

func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int{ 
    return titles.count 
}