picker view error

Question

Ive created a ViewController and placed a Picker View on it - my app has three items in the array named First Second and Third, it also has a button on the ViewController to allow me to scroll to eith First Second or Third and a button below to select that item.

I have three other ViewControllers named FirstViewController, SecondViewController and ThirdViewController and I want to scroll the Picker and select one of these Three ViewControllers to show here is my code

import UIKit

class ViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {

@IBAction func continueButtonPressed(_ sender: AnyObject) {

self.performSegue(withIdentifier: "\(chosenState)1", sender: nil)

print("no chance")

}

@IBOutlet weak var pickerView: UIPickerView!

var pickerData = ["First","Second","Third"]

var chosenState = ""

override func viewDidLoad() {

super.viewDidLoad()

print("Help")

pickerView.delegate = self

pickerView.dataSource = self

/

}

override func didReceiveMemoryWarning() {

super.didReceiveMemoryWarning()

/

}

/

func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {

return pickerData.count

}

/

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

return pickerData[row]

}

/

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

chosenState = pickerData[row]

}

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

return 1

}

_____________________________________________________

This is my debug console output

Help

2018-03-04 09:04:27.969852+0000 Scroller[21634:3399958] Unknown class FirstViewController in Interface Builder file.

no chance

Help

2018-03-04 09:04:31.916170+0000 Scroller[21634:3399958] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Receiver (<Scroller.ViewController: 0x7f9e7e416420>) has no segue with identifier 'Second1''

*** First throw call stack:

(

the annoying thing is it works sometimes

Can anyone help me work this out

Regards

Jeremy

Xcode

770

Posted by

JeremyGriffin

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Answer 1

When you post code, please use the code formatting tool (<>) that makes reading much more comfortable.

In addition, I find it better to declare IBOutlet and properties first, before the actions ; it is good also to insert MARK pragmas, for your future search in code.

import UIKit
class ViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {

    @IBOutlet weak var pickerView: UIPickerView!

    var pickerData = ["First","Second","Third"]
    var chosenState = ""

     // MARK: - lifecycle
    override func viewDidLoad() {
        super.viewDidLoad()
        print("Help")
        pickerView.delegate = self
        pickerView.dataSource = self
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

     // MARK: - IBActions
   @IBAction func continueButtonPressed(_ sender: AnyObject) {
        self.performSegue(withIdentifier: "\(chosenState)1", sender: nil)
        print("no chance")
    }


     // MARK: - picker delegate
    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        return pickerData.count
    }

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

    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
        chosenState = pickerData[row]
    }

    func numberOfComponents(in pickerView: UIPickerView) -> Int {
        return 1
    }

}

From your log:

1. viewDidload works OK

2. Unknown class FirstViewController in Interface Builder file.

Are you sure you have declared the destination viewController in IB as a FirstViewController ?

3. Terminating app due to uncaught exception

The segue is not found. In:

    @IBAction func continueButtonPressed(_ sender: AnyObject) {
        self.performSegue(withIdentifier: "\(chosenState)1", sender: nil)
        print("no chance")
    }

Are you sure you have defined a segue in IB with identifier as Second1

Note: to help debug, give more information in the print :

print("no chance with \(chosenState)1")

Posted by

Claude31

Add a Comment

Answer 2

When you post code, please use the code formatting tool (<>) that makes reading much more comfortable.

In addition, I find it better to declare IBOutlet and properties first, before the actions ; it is good also to insert MARK pragmas, for your future search in code.

import UIKit
class ViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {

    @IBOutlet weak var pickerView: UIPickerView!

    var pickerData = ["First","Second","Third"]
    var chosenState = ""

     // MARK: - lifecycle
    override func viewDidLoad() {
        super.viewDidLoad()
        print("Help")
        pickerView.delegate = self
        pickerView.dataSource = self
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

     // MARK: - IBActions
   @IBAction func continueButtonPressed(_ sender: AnyObject) {
        self.performSegue(withIdentifier: "\(chosenState)1", sender: nil)
        print("no chance")
    }


     // MARK: - picker delegate
    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        return pickerData.count
    }

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

    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
        chosenState = pickerData[row]
    }

    func numberOfComponents(in pickerView: UIPickerView) -> Int {
        return 1
    }

}

From your log:

1. viewDidload works OK

2. Unknown class FirstViewController in Interface Builder file.

Are you sure you have declared the destination viewController in IB as a FirstViewController ?

3. Terminating app due to uncaught exception

The segue is not found. In:

    @IBAction func continueButtonPressed(_ sender: AnyObject) {
        self.performSegue(withIdentifier: "\(chosenState)1", sender: nil)
        print("no chance")
    }

Are you sure you have defined a segue in IB with identifier as Second1

Note: to help debug, give more information in the print :

print("no chance with \(chosenState)1")

Posted by

Claude31

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picker view error

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