Swift NSAttributedStringKey not applying foreground color correctly

Question

I am trying to create a meme generator app to better my understanding of Swift, Xdode, delegates, and UIKit. I am attempting to set the color of the meme text to white with a black stroke using NSAttributedStringKey. The black stroke is working, but the foreground color is not being applied when the user selects an image from the camera roll. I have searched through StackOverflow, but all of the solutions are applicable to Swift 3, not Swift 4. Where am I going wrong?

I have included my source code below.

import UIKit

class ViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate {

    @IBOutlet weak var imagePickerView: UIImageView!
    @IBOutlet weak var cameraButton: UIBarButtonItem!
    @IBOutlet weak var topText: UITextField!
    @IBOutlet weak var bottomText: UITextField!

    let memeTextAttributes:[String:Any] = [
        NSAttributedStringKey.strokeColor.rawValue: UIColor.black,
        NSAttributedStringKey.foregroundColor.rawValue: UIColor.white,
        NSAttributedStringKey.font.rawValue: UIFont(name: "HelveticaNeue-CondensedBlack", size: 40)!,
        NSAttributedStringKey.strokeWidth.rawValue: 3.0]

    override func viewDidLoad() {
        super.viewDidLoad()
        // Diable camer a button if camera ource isn't available
        cameraButton.isEnabled = UIImagePickerController.isSourceTypeAvailable(.camera)
        topText.defaultTextAttributes = memeTextAttributes
        bottomText.defaultTextAttributes = memeTextAttributes
    }

    // MARK: Delegate Methods

    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {
        if let image = info[UIImagePickerControllerOriginalImage] as? UIImage {
            imagePickerView.image = image
            self.dismiss(animated: true, completion: nil)
        }
    }

    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
        self.dismiss(animated: true, completion: nil)
    }

    @IBAction func pickAnImageFromAlbum(_ sender: Any) {
        let pickerController = UIImagePickerController()
        pickerController.delegate = self
        pickerController.sourceType = .photoLibrary
        present(pickerController, animated: true, completion: nil)
    }

    @IBAction func pickAnImageFromCamera(_ sender: Any) {
        let imagePicker = UIImagePickerController()
        imagePicker.delegate = self
        imagePicker.sourceType = .camera
        present(imagePicker, animated: true, completion: nil)
    }
}

Answer 1

Use negative strokeWidth if you'll set foregroundColor as well. Otherwise, only the stroke is seen.

let attributes = [
        NSAttributedStringKey.strokeColor.rawValue: UIColor.black,
        NSAttributedStringKey.backgroundColor.rawValue: UIColor.red,
        NSAttributedStringKey.foregroundColor.rawValue: UIColor.white,
        NSAttributedStringKey.font.rawValue: UIFont(name: "HelveticaNeue-CondensedBlack", size: 40)!,
        NSAttributedStringKey.strokeWidth.rawValue: -4.5]

Swift 5

let attributes = [
        NSAttributedString.Key.strokeColor: UIColor.black,
        NSAttributedString.Key.backgroundColor: UIColor.red,
        NSAttributedString.Key.foregroundColor: UIColor.white,
        NSAttributedString.Key.font: UIFont(name: "HelveticaNeue-CondensedBlack", size: 40)!,
        NSAttributedString.Key.strokeWidth: -3.0]

Edit: See rmaddy's comment about why we need the rawValue in this case below.