Swift UIAlert - Daten von dataTaskWithRequest abrufen

Question

Ich brauche die Variable 'response', die aus "dataTaskWithRequest" entnommen werden kann. Momentan wird 'Antwort' nicht gefunden, da sie außerhalb der Klammern liegt. Wie kann ich sicherstellen, dass die Antwortvariable an das UIAlert übergeben wird? Dank

Hier ist mein Code:

@IBAction func buttonCreateAccount(sender: AnyObject) { 
      let request = NSMutableURLRequest(URL: NSURL(string: "http://www.example.com/createaccount.php")!) 
      request.HTTPMethod = "POST" 
      let postString = "user_name=\(username.text!)&email=\(email.text!)&password=\(password.text!)" 
      request.HTTPBody = postString.dataUsingEncoding(NSUTF8StringEncoding) 

      let task = NSURLSession.sharedSession().dataTaskWithRequest(request) { 
       data, response, error in 

       if error != nil { 
        print("error=\(error)") 
        return 
       } 

       print("response = \(response)") 

       let response = String(data: data!, encoding: NSUTF8StringEncoding) 
       print("responseString = \(response)") 

      } 

      task.resume() 

//problem is here. 'response' variable cannot be taken from above. i need it to be taken from above. 
      if response == "Username taken" { 
       if let getModernAlert: AnyClass = NSClassFromString("UIAlertController") { // iOS 8 
        let myAlert: UIAlertController = UIAlertController(title: "Registration", message: response, preferredStyle: .Alert) 
        myAlert.addAction(UIAlertAction(title: "OK", style: .Default, handler: nil)) 
        self.presentViewController(myAlert, animated: true, completion: nil) 
       } else { // iOS 7 
        let alert: UIAlertView = UIAlertView() 
        alert.delegate = self 

        alert.title = "Registration" 
        alert.message = "Testing" 
        alert.addButtonWithTitle("OK") 

        alert.show() 
       } 
      } else { 
       if let getModernAlert: AnyClass = NSClassFromString("UIAlertController") { // iOS 8 
        let myAlert: UIAlertController = UIAlertController(title: "Registration", message: response, preferredStyle: .Alert) 
        myAlert.addAction(UIAlertAction(title: "OK", style: .Default, handler: nil)) 
        self.presentViewController(myAlert, animated: true, completion: nil) 
       } else { // iOS 7 
        let alert: UIAlertView = UIAlertView() 
        alert.delegate = self 

        alert.title = "Registration" 
        alert.message = "Testing" 
        alert.addButtonWithTitle("OK") 

        alert.show() 
        self.dismissViewControllerAnimated(true, completion: {}); 
       } 
      } 
     } 

Answer 1

dataTaskWithRequest läuft asynchron. Sie werden die Antwort nicht sofort erhalten. Trennen Sie es in zwei Funktionen:.

@IBAction func buttonCreateAccount(sender: AnyObject) { 
    let request = NSMutableURLRequest(URL: NSURL(string: "http://www.example.com/createaccount.php")!) 
    request.HTTPMethod = "POST" 
    let postString = "user_name=\(username.text!)&email=\(email.text!)&password=\(password.text!)" 
    request.HTTPBody = postString.dataUsingEncoding(NSUTF8StringEncoding) 

    let task = NSURLSession.sharedSession().dataTaskWithRequest(request) { 
     data, response, error in 

     if error != nil { 
      print("error=\(error)") 
      return 
     } 

     print("response = \(response)") 

     let response = String(data: data!, encoding: NSUTF8StringEncoding) 
     print("responseString = \(response)") 

     // Now that the response is ready, call the other function to handle it 
     handleResponse(response) 
    } 

    task.resume() 
} 

func handleResponse(response: String) { 
    if response == "Username taken" { 
     if let getModernAlert: AnyClass = NSClassFromString("UIAlertController") { // iOS 8 
      let myAlert: UIAlertController = UIAlertController(title: "Registration", message: response, preferredStyle: .Alert) 
      myAlert.addAction(UIAlertAction(title: "OK", style: .Default, handler: nil)) 
      self.presentViewController(myAlert, animated: true, completion: nil) 
     } else { // iOS 7 
      let alert: UIAlertView = UIAlertView() 
      alert.delegate = self 

      alert.title = "Registration" 
      alert.message = "Testing" 
      alert.addButtonWithTitle("OK") 

      alert.show() 
     } 
    } else { 
     if let getModernAlert: AnyClass = NSClassFromString("UIAlertController") { // iOS 8 
      let myAlert: UIAlertController = UIAlertController(title: "Registration", message: response, preferredStyle: .Alert) 
      myAlert.addAction(UIAlertAction(title: "OK", style: .Default, handler: nil)) 
      self.presentViewController(myAlert, animated: true, completion: nil) 
     } else { // iOS 7 
      let alert: UIAlertView = UIAlertView() 
      alert.delegate = self 

      alert.title = "Registration" 
      alert.message = "Testing" 
      alert.addButtonWithTitle("OK") 

      alert.show() 
      self.dismissViewControllerAnimated(true, completion: {}); 
     } 
    } 
}