Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

iOS Build an Interactive Story App with Swift Personalizing the Story Modifying Constraints

Bastian Petersson
Bastian Petersson
9,164 Points

Text field not moving

When I run the app and click on the text field it still doesn't work. I have no errors. Can anyone else spot the problem?

import UIKit

class ViewController: UIViewController {

    @IBOutlet var nameTextField: UITextField!
    @IBOutlet var textFieldBottumConstraint: NSLayoutConstraint!

    override func viewDidLoad() {

        NotificationCenter.default.addObserver(self, selector: #selector(ViewController.keyboardWillShow), name: Notification.Name.UIKeyboardWillHide, object: nil)

    override func didReceiveMemoryWarning() {
        // Dispose of any resources that can be recreated.

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if segue.identifier == "startAdventure" {

            do {
                if let name = nameTextField.text {
                    if name == "" {
                        throw AdventureError.nameNotProvided
                    } else {
                        guard let pageController = segue.destination as? PageController else {
                            return }

                        pageController.page = Adventure.story(withName: name)
        } catch AdventureError.nameNotProvided {
            let alertController = UIAlertController(title: "Name Not Provided", message: "Provide a name to start the story", preferredStyle: .alert)

            let action = UIAlertAction(title: "OK", style: .default, handler: nil)
            present(alertController, animated: true, completion: nil)
            }catch let error {

    @objc func keyboardWillShow(_ notification: Notification) {
        if let info = notification.userInfo, let keyboardFrame = info["UIKeyboardFrameEndUserInfoKey"] as? NSValue {
            let frame = keyboardFrame.cgRectValue
            textFieldBottumConstraint.constant = frame.size.height + 10

            UIView.animate(withDuration: 0.8) {

    deinit {

2 Answers

Caleb Kleveter
Caleb Kleveter
Treehouse Moderator 37,862 Points

The only difference I saw between your code and Pasan's was the #selector literal for the keyboard notification:

    selector: #selector(ViewController.keyboardWillShow), // <== This argument
    name: Notification.Name.UIKeyboardWillHide, 
    object: nil

Pasan's implementation has the parameter list of the method:


Hope that fixes it!

Bastian Petersson
Bastian Petersson
9,164 Points

This was exactly what was wrong. I was able to figure it out myself. But thanks for the help anyway!?