The timer starts and countdowns while updating the title of the button when the view is loaded. I've called startTimer in viewDidLoad. This works fine as expected.
However, the problem I faced is when I call startTimer from the IBAction. I've verified the timer is working and the selector is being called. The button title doesn't change tho. What could be wrong in this case?
class ViewController: UIViewController {
#IBOutlet weak var button: UIButton?
var timer: Timer?
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
startTimer()
}
func startTimer() {
countdownSeconds = 60
timer?.invalidate()
timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(updateTimer), userInfo: nil, repeats: true)
}
#objc func updateTimer() {
countdownSeconds -= 1
let countdown = countdownFormatter.string(from: TimeInterval(countdownSeconds))!
if countdownSeconds > 0 {
UIView.performWithoutAnimation {
button?.setTitle(countdown, for: .normal)
}
} else {
timer?.invalidate()
}
}
#IBAction func buttonTapped(_ sender: UIButton) {
startTimer()
}
}
Related
I am a complete beginner and am starting to learn the Swift programming language. I'm following a tutorial on Udemy and am having some problems with setting up a timer.
class ViewController: UIViewController {
#IBOutlet weak var label: UILabel!
var timer1 = Timer()
var counter = 0
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
label.text = String(counter)
}
#IBAction func start(_ sender: Any) {
timer1 = Timer(timeInterval: 1, target: self, selector: #selector(tim), userInfo: nil, repeats: true)
}
#IBAction func pause(_ sender: Any) {
timer1.invalidate()
}
#IBAction func restart(_ sender: Any) {
timer1.invalidate()
counter = 0
label.text = String(counter)
}
#objc func tim() {
counter += 1
label.text = String(counter)
}
}
This is my code but the timer is not working. Please tell me where im going wrong.
You need to add timer to RunLoop
RunLoop.current.add(timer1, forMode: .commonModes)
Or use scheduledTimer
timer1 = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(tim), userInfo: nil, repeats: true)
Also in your restart function you need to do it again, because now you are just invalidating it and not starting again.
When 10 seconds hit the timer. I would like the background color to be change. Right now my code is not working. Nothing is being changed when the code hits 10 seconds. I also dont think the timer is working.
#IBOutlet var espn: UILabel!
var TIMER = Timer()
var seconds = 0
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
if seconds == 10{self.view.backgroundColor = UIColor.red
}
}
#IBAction func startTimer() {
TIMER = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(threeVC.clocker), userInfo: nil, repeats: true)
}
#objc func clocker() {
seconds += 1
espn.text = String( seconds)
}
}
Try this code:
#IBOutlet var espn: UILabel!
var TIMER = Timer()
var seconds = 0
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
}
#IBAction func startTimer() {
TIMER = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(threeVC.clocker), userInfo: nil, repeats: true)
}
#objc func clocker() {
seconds += 1
espn.text = String( seconds)
if seconds == 10{
self.view.backgroundColor = UIColor.red
print("soda")
}
}
if statement should be written in #objc func clocker() not in viewDidAppear
I am making timer. I cannot figure out how to make start button tapped only once as it is starting to count. And at stop button timer.invalidate() does not work
#IBAction func start(_ sender: Any) {
timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(W1ViewController.counter), userInfo: nil, repeats: true)
}
#IBOutlet weak var stopOutlet: UIButton!
#IBAction func stop(_ sender: Any) {
seconds = 30
label.text = "\(seconds)"
timer.invalidate()
audioPlayer.stop()
}
Just disable the button
#IBAction func start(_ sender: Any) {
stopOutlet.isEnabled = false
timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(W1ViewController.counter), userInfo: nil, repeats: true)
}
Then re-enable when needed:
stopOutlet.isEnabled = true
UIButton extends UIControl. UIControl provides this and alot more functionality to all controls.
I'm currently learning Swift and iOS programming. I want to make a timer that starts with a long press on the button. At the same time I want to change the UIButton image. I leave button, I want the button revert back. Is this possible?
You absolutely can do this. You have to add LongPressGestureRecognizer:
let longPress = UILongPressGestureRecognizer(target: self, action: #selector(yourAction))
button.addGestureRecognizer(longPress)
And then in your func start the timer and change the button's image:
func yourAction(){
Timer.scheduledTimer(timeInterval: 5, target: self, selector: #selector(timerAction), userInfo: nil, repeats: false)
button.setImage(UIImage(named: "yourImage"), for: .normal)
}
func timerAction(){
//Do whatever you want
}
You need to implement your own solution for this, something along the lines
1- User touches down (UIControlEvent touchDown), you start a time that fires every x secs/millisecs
2- Timer will fire the action over and over
3- User touches up UICOntrolEvent touchUp, you cancel your timer
So you bind those 2 events to different functions, and start/kill your timers with appropriate actions
How that helps
I will add a code for demonstration:
#IBOutlet var button: UIButton!
var timer: Timer!
var speedAmmo = 100
#IBAction func buttonDown(sender: AnyObject) {
singleFire()
timer = Timer.scheduledTimer(timeInterval: 0.1, target: self, selector:#selector(rapidFire), userInfo: nil, repeats: true)
}
#IBAction func buttonUp(sender: AnyObject) {
timer.invalidate()
}
func singleFire() {
if speedAmmo > 0 {
speedAmmo -= 1
print("bang!")
} else {
print("out of speed ammo, dude!")
timer.invalidate()
}
}
func rapidFire() {
if speedAmmo > 0 {
speedAmmo -= 1
print("bang!")
} else {
print("out of speed ammo, dude!")
timer.invalidate()
}
}
override func viewDidLoad() {
super.viewDidLoad()
button.addTarget(self, action:#selector(buttonDown(sender:)), for: .touchDown)
button.addTarget(self, action:#selector(buttonUp(sender:)), for: [.touchUpInside, .touchUpOutside])
}
Please try and let me know!
I'm trying to make a simple timer in iOS using Swift.
The program is working fine but whenever my START UIButton is pressed the function of timer starts and runs multiple time as much as the button is pressed.
I want to disable the START UIButton as soon as the timer function starts so that it does not run multiple times.
Please help me for the same.
This is my code of ViewController
import UIKit
class ViewController: UIViewController {
var time = 0.0
var timer = Timer()
#IBOutlet weak var lbl: UILabel!
#IBAction func start(_ sender: UIButton)
{
timer = Timer.scheduledTimer(timeInterval: 0.1, target: self, selector: #selector(ViewController.action), userInfo: nil, repeats: true)
}
#IBAction func pause(_ sender: UIButton)
{
timer.invalidate()
}
#IBAction func reset(_ sender: UIButton)
{
timer.invalidate()
time = 0.0
lbl.text = ("0")
}
func action()
{
time += 0.1
lbl.text = String(time)
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
To disable your button you can just set it's isUserInteractionEnabled property in start function:
#IBOutlet weak var startButton: UIButton!
#IBAction func start(_ sender: UIButton) {
timer = Timer.scheduledTimer(timeInterval: 0.1, target: self, selector: #selector(ViewController.action), userInfo: nil, repeats: true)
startButton.isEnabled = false
}
Then set it back to true in pause and reset methods:
#IBAction func pause(_ sender: UIButton) {
timer.invalidate()
startButton.isEnabled = true
}
#IBAction func reset(_ sender: UIButton) {
timer.invalidate()
startButton.isEnabled = true
//the rest of your code
}
The most reliable way to ensure that the timer is only started and stopped once is writing two methods which check the current state (timer is not nil if it's currently running):
var timer : Timer?
func startTimer()
{
guard timer == nil else { return }
timer = Timer.scheduledTimer(timeInterval: 0.1, target: self, selector: #selector(ViewController.action), userInfo: nil, repeats: true)
// disable start button
}
func stopTimer()
{
guard timer != nil else { return }
timer!.invalidate()
timer = nil
// enable start button
}
In the methods you can enable/disable the button(s) accordingly.