Getting error `Do you want to add protocol stubs? [duplicate] - ios

Question

This question already has answers here:
Xcode 8 says "Do you want to add a stub?" How do I answer?
(3 answers)
Closed 4 years ago.
I added the ImageView Protocol. What can be done to remove the error
Do you want to add protocol stubs?
CardsViewController
import UIKit
protocol ImageViewProtocol{
func sendImageToViewController(theImage: UIImage)
}
class CardsViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate, ImageViewProtocol {
#IBOutlet weak var textField: UITextField!
#IBOutlet weak var nameTextField: UITextField!
#IBOutlet weak var locationTextField: UITextField!
#IBOutlet weak var imageView: UIImageView!
#IBAction func goToViewController2Action(_ sender: Any)
{
let viewcontroller2 = storyboard?.instantiateViewController(withIdentifier: "viewController2") as! ViewController2
viewcontroller2.delegate = self
self.navigationController?.pushViewController(viewcontroller2, animated: true)
}
func chooseImagePickerAction(source: UIImagePickerController.SourceType) {
if UIImagePickerController.isSourceTypeAvailable(source) {
let imagePicker = UIImagePickerController()
imagePicker.delegate = self
imagePicker.allowsEditing = true
imagePicker.sourceType = source
self.present(imagePicker, animated: true, completion: nil)
}
}
#IBAction func saveButtonPressed(_ sender: UIBarButtonItem) {
if nameTextField.text == "" || locationTextField.text == "" || textField.text == "" {
print("Not all fields are filled")
} else {
if let context = (UIApplication.shared.delegate as? AppDelegate)?.coreDataStack.persistentContainer.viewContext {
let card = Card(context: context)
card.name = nameTextField.text
card.location = locationTextField.text
card.number = textField.text
if let image = imageView.image {
card.image = image.pngData()
}
do {
try context.save()
print("Cохранение удалось!")
} catch let error as NSError {
print("Не удалось сохранить данные \(error), \(error.userInfo)")
}
}
performSegue(withIdentifier: "unwindSegueFromNewCard", sender: self)
}
}
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
imageView.image = info[UIImagePickerController.InfoKey.editedImage] as? UIImage
imageView.contentMode = .scaleAspectFill
imageView.clipsToBounds = true
dismiss(animated: true, completion: nil)
}
}
ViewController2
import UIKit
class ViewController2: UIViewController {
var filter : CIFilter!
var delegate: ImageViewProtocol!
#IBOutlet weak var select: UISegmentedControl!
#IBOutlet weak var textField: UITextField!
#IBOutlet weak var barcodeImageView: UIImageView!
override func viewDidLoad() {
super.viewDidLoad()
barcodeImageView.image = UIImage(named: "photo")
}
#IBAction func saveButtonAction(_ sender: Any) {
if textField.text == "" {
print("Not all fields are filled")
} else {
delegate.sendImageToViewController(theImage: barcodeImageView.image!)
self.navigationController?.popViewController(animated: true)
}
performSegue(withIdentifier: "unwindSegueFromViewController", sender: sender)
}
#IBAction func tappedEnter(_ sender: Any) {
if textField.text?.isEmpty ?? true {
return
} else {
if let texttxt = textField.text {
let data = texttxt.data(using: .ascii, allowLossyConversion: false)
if select.selectedSegmentIndex == 0
{
filter = CIFilter(name: "CICode128BarcodeGenerator")
} else {
filter = CIFilter(name: "CIQRCodeGenerator")
}
filter.setValue(data, forKey: "inputMessage")
let transform = CGAffineTransform(scaleX: 5, y: 5)
let image = UIImage(ciImage: filter.outputImage!.transformed(by: transform))
barcodeImageView.image = image
}
}
}
}

Answer 1

This error comes because you implemented protocol (ImageViewProtcol) but you haven't add required methods of your protocol (in your case sendImageToViewController(theImage: UIImage)). All methods of your protocol are required by default. If you want to change it, you can look here.
It's the same as when you're implementing UITableViewDataSource, you also need to add required methods like number of items etc.
To fix this, add this method to your CardsViewController:
func sendImageToViewController(theImage: UIImage) {
// do something with image
}