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.
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.
this is i seting a timer function, the code like this:
#IBAction func start(_ sender: UIButton) {
Timer.scheduledTimer(timeInterval: 1,
target: self,
selector:#selector(ViewController.action),
userInfo: nil,
repeats: true)
}
#objc func action() {
hoursMinutesSeconds()
if stop == true{
start = false
timer.invalidate()
timer.invalidate()
time = 0
}
}
#IBAction func stop(_ sender: UIButton){
start = false
timer.invalidate()
timer.invalidate()
time = 0
}
but, when i click the stop func, this function not work. mean is the timer not stop. timer stil working…… why？ thank you for your time!!
I think you didn't set timer value
timer = Timer.scheduledTimer(timeInterval: 1,
target: self,
selector:#selector(ViewController.action),
userInfo: nil,
repeats: true)
First you have to declare it as fileprivate as below:
fileprivate var timer = Timer()
#IBAction func start(_ sender: UIButton) {
self.timer = Timer.scheduledTimer(timeInterval: 4,
target: self,
selector: #selector(self.updateTimerForLocation),
userInfo: nil,
repeats: true)
}
#IBAction func stop(_ sender: UIButton) {
timer.invalidate()
}
Ensure that you are invalidating correct instance of Timer.
Like in start function, you didn't assign timer instance to any object, but in stop function,you are using timer vaiable to stop that timer.
Which means you try to invalidate a variable, which never instantiated.
Still try below function to stop timer, after assigning timer variable.
#IBAction func stop(_ sender: UIButton) {
start = false
timer.invalidate()
timer = nil
time = 0
}
Hope this work
you are confusing between variable stop and func stop.
also you dont need 2 parameter to manage stop/start status
--
for your question,
you should retain the timer variable to able to use it in other func
declare a global timer
var timer: Timer!
then
timer = Timer.scheduledTimer(timeInterval: 1,
target: self,
selector:#selector(ViewController.action),
userInfo: nil,
repeats: true)
now you can invalidate it anywhere
I want to access myTimer variable from startTimer() function inside my backBtnPressed() function. Basically i want to add this code myTimer.invalidate() inside my backBtnPressed() function. How can i achieve that?
func startTimer() {
var myTimer = Timer.scheduledTimer(timeInterval: 3.0,
target: self,
selector: #selector(scrollToNextCell),
userInfo: nil,
repeats: true)
}
#IBAction func backBtnPressed(_ sender: UIButton) {
audioPlayer.stop()
}
As it stands now, you cannot access myTimer variable outside startTimer(), because it is outside the scope. For that, you need to declare myTimer as a Class variable. Them, you need to initialize it, as you are doing, and them you can access whatever you want inside the Class. Also don't forget to call startTimer, or it will return nil.
It looks more or less like this:
class YourViewController: ViewController {
var myTimer: Timer?
//some of your functions here
//...
override func viewDidLoad() {
super.viewDidLoad()
//...
startTimer()
}
func startTimer() {
myTimer = Timer.scheduledTimer(timeInterval: 3.0,
target: self,
selector: #selector(yourFunction),
userInfo: nil,
repeats: true)
}
#IBAction func backBtnPressed(_ sender: UIButton) {
//do whatever you want
myTimer.invalidate()
}
}
Simple make your timer a property:
class MyClass {
var timer: Timer?
func startTimer() {
timer = Timer.scheduledTimer(timeInterval: 3.0, target: self, selector: #selector(scrollToNextCell), userInfo: nil, repeats: true)
}
#IBAction func backBtnPressed(_ sender: UIButton) {
audioPlayer.stop()
timer.//do something with timer
}
}
I am a beginner so I may not see obvious things at this point. So please, help. I need my startButton enabled again when pauseButton is pressed and vice versa. I cannot create a var that can be accessed by both UIButton functions though. What should I do? Here's part of my code:
#IBAction func Start(_ sender: AnyObject) {
let disableMyStartButton = sender as? UIButton
disableMyStartButton?.isEnabled = false
timer = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(ViewController.update), userInfo: nil, repeats: true)
}
#IBAction func pauseTimer(_ sender: AnyObject) {
timer.invalidate()
WarningLabel.text = "Paused"
}
You need to create Outlet of your buttons and use them in your methods.
#IBOutlet var btnStart: UIButton!
#IBOutlet var btnPause: UIButton!
#IBAction func start(_ sender: UIButton) {
sender.isEnabled = false
btnPause.isEnabled = true
timer = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(ViewController.update), userInfo: nil, repeats: true)
}
#IBAction func pauseTimer(_ sender: UIButton) {
sender.isEnabled = false
btnStart.isEnabled = true
timer.invalidate()
WarningLabel.text = "Paused"
}
You can also done this thing using single action for buttons like this.
#IBAction func onStartOrPause(_ sender: UIButton) {
if (sender == btnStart) {
sender.isEnabled = false
btnPause.isEnabled = true
timer = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(ViewController.update), userInfo: nil, repeats: true)
}
else {
sender.isEnabled = false
btnStart.isEnabled = true
timer.invalidate()
WarningLabel.text = "Paused"
}
}
Note: You can also make same thing using single button by changing title or image of it in the action.
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.