iOS Development - Timer App

Click Main.StoryBoard.

Add a label to display the seconds (We are going to set 240 as default ). Resize it in Properties menu.

Add a navigation bar to the top and change the title of Timer.

Add two Bar buttons on the top navigation bar and change the System Item into play and pause.

Add a Toolbar to the bottom and rename the item to “-10”.

Add two bar button items and name them “Reset “and “+10”.

Click ViewController.Swift.

Now, control + drag label to the program and name it “timerLabel”.

Control + drag each button to the code and name them “play”,”pause”,”minusTen”,”plusTen”,”resetTimer”(Connection type must be Button).

Edit the code, as given below.

1. import UIKit
2. class ViewController: UIViewController {
3. var timer = Timer()
4. var time = 240
5. func decreaseTimer() {
6. if time > 0 {
7. time = time - 1
8. timerLabel.text = String(time)
9. } else {
10. timer.invalidate()
11. }
12. }
13. @IBOutlet weak
14. var timerLabel: UILabel!@IBAction func play(_ sender: Any) {
15. timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(ViewController.decreaseTimer), userInfo: nil, repeats: true)
16. }
17. @IBAction func pause(_ sender: Any) {
18. timer.invalidate()
19. }
20. @IBAction func minusTen(_ sender: Any) {
21. if time > 10 {
22. time -= 10
23. timerLabel.text = String(time)
24. }
25. }
26. @IBAction func plusTen(_ sender: Any) {
27. time += 10
28. timerLabel.text = String(time)
29. }
30. @IBAction func resetTimer(_ sender: Any) {
31. time = 240
32. timerLabel.text = String(time)
33. }
34. override func viewDidLoad() {
35. super.viewDidLoad()
36. // Do any additional setup after loading the view, typically from a nib.
37. }
38. override func didReceiveMemoryWarning() {
39. super.didReceiveMemoryWarning()
40. // Dispose of any resources that can be recreated.
41. }
42. }

Now, run the app.