Q:

Image selected from iOS PhotoLibrary doesn't show in UIImageView

I'm trying to use a UIImagePickerController to show a image picked from the Photo Library, but when I select the image, nothing happens.
All I'm doing is from Apple's Swift tutorial, so the code shouldn't be wrong, I guess. It doesn't work neither in simulator nor on a real device. I've tried all suggestions I found while googling. My code:
import UIKit

class ViewController: UIViewController, UITextFieldDelegate, UIImagePickerControllerDelegate, UINavigationControllerDelegate {

//MARK: Properties
@IBOutlet weak var nameTextField: UITextField!
@IBOutlet weak var mealNameLabel: UILabel!
@IBOutlet weak var photoImageView: UIImageView!

override func viewDidLoad() {
    super.viewDidLoad()
    nameTextField.delegate = self
}

//MARK: Actions

@IBAction func selectImageFromPhotoLibrary(sender: UITapGestureRecognizer) {

    // Hide the keyboard.
    nameTextField.resignFirstResponder()

    // UIImagePickerController is a view controller that lets a user pick media from their photo library.
    let imagePickerController = UIImagePickerController()

    // Only allow photos to be picked, not taken.
    imagePickerController.sourceType = .photoLibrary

    // Make sure ViewController is notified when the user picks an image.
    imagePickerController.delegate = self
    present(imagePickerController, animated: true, completion: nil)

    func imagePickerControllerDidCancel(picker: UIImagePickerController) {
        // Dismiss the picker if the user canceled.
        dismiss(animated: true, completion: nil)
    }

    func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {

        // The info dictionary may contain multiple representations of the image. You want to use the original.
        guard let selectedImage = info[UIImagePickerControllerOriginalImage] as? UIImage else {
            fatalError("Expected a dictionary containing an image, but was provided the following: \(info)")
        }

        // Set photoImageView to display the selected image.
        photoImageView.image = selectedImage

        // Dismiss the picker.
        dismiss(animated: true, completion: nil)
    }
}

@IBAction func setDefaultLabelText(sender: UIButton) {
    mealNameLabel.text = "Default Text"
}

//MARK: UITextFieldDelegate

func textFieldShouldReturn(_ textField: UITextField) -> Bool {
    textField.resignFirstResponder()
    return true
}

func textFieldDidEndEditing(_ textField: UITextField) {
    mealNameLabel.text = textField.text
}
}

I can provide more information if necessary. Thanks in advance.

A:

Your delegate method is in the button action scope.
You have to write UIImagePickerControllerDelegate method out of the selectImageFromPhotoLibrary action scope and write with the proper signature.
Just like that:
@IBAction func selectImageFromPhotoLibrary(sender: UITapGestureRecognizer) {

    // Hide the keyboard.
    nameTextField.resignFirstResponder()

    // UIImagePickerController is a view controller that lets a user pick media from their photo library.
    let imagePickerController = UIImagePickerController()

    // Only allow photos to be picked, not taken.
    imagePickerController.sourceType = .photoLibrary

    // Make sure ViewController is notified when the user picks an image.
    imagePickerController.delegate = self
    present(imagePickerController, animated: true, completion: nil)

    }
func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
            // Dismiss the picker if the user canceled.
            dismiss(animated: true, completion: nil)
        }

    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {

        // The info dictionary may contain multiple representations of the image. You want to use the original.
        guard let selectedImage = info[UIImagePickerControllerOriginalImage] as? UIImage else {
            fatalError("Expected a dictionary containing an image, but was provided the following: \(info)")
        }

        // Set photoImageView to display the selected image.
        photoImageView.image = selectedImage

        // Dismiss the picker.
        dismiss(animated: true, completion: nil)
    }

