I'm trying to get output like so:
1 (then a one second delay)
Hello
2 (then a one second delay)
Hello
3 (then a one second delay)
Hello
But instead I get
1
2
3 (then a one second delay)
Hello
Hello
Hello
Here's my for loop invoking the NSTimer
var timer = NSTimer()
for i in 1...3 {
print("\(i)");
timer = NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: #selector(MainVPScreenViewController.printTest), userInfo: nil, repeats: false)
}
And here's the selector method:
func printTest() {
print("Hello")
}
Thanks in advance for any help you can provide
Try this solution without NSTimer:
var i = 1
func printHello() {
print(i)
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, Int64(1 * Double(NSEC_PER_SEC))), dispatch_get_main_queue()) {
print("Hello")
i +=1
if i <= 3 {
printHello()
}
}
}
override func viewDidLoad() {
super.viewDidLoad()
printHello()
}
I need 2 NSTimers to do this, this is my approach
class ViewController: UIViewController {
var i = 1
override func viewDidLoad() {
super.viewDidLoad()
beginPrinting()
}
func beginPrinting() {
var timer2 = NSTimer()
if(i <= 100)
{
timer2 = NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: #selector(self.printWithDelay), userInfo: nil, repeats: false)
}
}
func printWithDelay()
{
var timer = NSTimer()
print("\(i)");
i += 1
timer = NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: #selector(self.printTest), userInfo: nil, repeats: false)
}
func printTest() {
print("Hello")
beginPrinting()
}
}
Hope this helps you
Use timer with repeat to true. So in your view controller would be like this
var timer = NSTimer()
var counter = 0
var max = 10
let delay = 1 // in second
override func viewDidLoad() {
super.viewDidLoad()
timer = NSTimer.scheduledTimerWithTimeInterval(delay, target: self,
selector: #selector(self.printTest), userInfo: nil, repeats: true)
}
func printTest() {
counter += 1
print(counter)
print(hello)
if counter == maxNumber {
timer.invalidate()
}
}
This does it with repeat false, and is set up to be in a playground:
import XCPlayground
XCPlaygroundPage.currentPage.needsIndefiniteExecution = true
#objc class Foo: NSObject {
static var timer = NSTimer()
var i:Int
override init() {
Foo.timer = NSTimer()
i = 1
}
func schedule() {
print("\n\(i)");
i += 1
Foo.timer = NSTimer.scheduledTimerWithTimeInterval(1.0,
target: self,
selector: #selector(printTest),
userInfo: nil,
repeats: false)
}
#objc func printTest() {
print("Hello")
if i < 5 {
schedule()
}
}
}
let bar = Foo()
bar.schedule()
Related
import UIKit
class ViewController: UIViewController {
let eggTimes = ["Soft": 60,"Medium": 72,"Hard": 95]
var secondsRemaining = 20
var timer = Timer()
#IBAction func hardnessSelected(_ sender: UIButton) {
let hardness = sender.currentTitle!
var secondsRemaining = eggTimes[hardness]!
timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(timerAction), userInfo: nil, repeats: true)
}
#objc func timerAction()
{
if secondsRemaining > 0 {
print("\(secondsRemaining) seconds")
secondsRemaining -= 1
}
}
}
Unexpected Output: I am using the below code to print out the timer according to the button pressed but timer is starting with 20 only. what's wrong?
You are creating a new variable inside your Button function:
var secondsRemaining = eggTimes[hardness]!
instead you should assing your value. It should be:
self.secondsRemaining = eggTimes[hardness]!
I can not stop the timer NSTimer created to perform secondary operations.
I have read and tried all sorts of possible Web guides but none have worked and the timer continues to run even when the Controller is destroyed. Below is the code in question:
/* Copy banner in a temp array and change order to random value */
private func getBanners(){
let realm = try! Realm()
let banners = self.synchronizer.getAllBanners()?.sorted("ordine")
if let banners = banners {
for banner in banners {
let random = Double.random(0.0, 1.0)
let currentOrderValue = banner.ordine
self.banners.append(banner)
do {
try realm.write({
self.banners.last!.ordine = currentOrderValue + random
})
} catch let error as NSError {
print(error)
}
}
}
}
/*Update index of banner to show */
func updateIndex(timer : NSTimer) {
if self.index+1 < self.banners.count {
for banner in self.banners{
print(banner.name + " \(banner.ordine)")
}
self.index+=1
} else {
self.index = 0
}
self.setImageBanner()
}
/* Set image of banner to show*/
private func setImageBanner() {
if self.banners.count > 0 {
self.bannerImage.hidden = false
let banner = self.banners[self.index]
let file = banner.images[0]
self.synchronizer.loadImageURL(file.link, imageView: self.bannerImage)
} else {
self.bannerImage.hidden = true
}
}
/* Start Timer */
func startTimerForBanners() {
dispatch_async(dispatch_get_main_queue(), { () -> Void in
self.getBanners()
})
self.timer = NSTimer(timeInterval: 5, target: self, selector: #selector(self.updateIndex(_:)), userInfo: nil, repeats: true)
NSRunLoop.currentRunLoop().addTimer(self.timer!, forMode: NSRunLoopCommonModes)
}
/* Open link on banner click */
func openLink(sender : UITapGestureRecognizer){
if self.index >= 0 && self.index < self.banners.count {
let banner = self.banners[self.index]
print(banner.name)
self.synchronizer.openLink(banner.url)
}
}
func trialLesson(sender : UITapGestureRecognizer){
performSegueWithIdentifier("trial_lesson_segue", sender: nil)
}
override func viewWillDisappear(animated: Bool) {
super.viewWillDisappear(animated)
if let timer = self.timer {
timer.invalidate()
}
}
you need to invalidate the timer before starting a new timer. Currently I believe you are calling "startTimerForBanners" many times may be, so many timer thread has been initiated. One approach is to invlidate all timer one by one or just invalidate before starting new one like this
/* Start Timer */
func startTimerForBanners() {
dispatch_async(dispatch_get_main_queue(), { () -> Void in
self.getBanners()
})
**self.timer.invalidate()**
self.timer = NSTimer(timeInterval: 5, target: self, selector: #selector(self.updateIndex(_:)), userInfo: nil, repeats: true)
NSRunLoop.currentRunLoop().addTimer(self.timer!, forMode: NSRunLoopCommonModes)
}
Are you sure that your controller is really deallocated?
There is one thing you should be always aware about NSTimer: it retains it's target.
I would suggest to:
Start your timer in viewWillAppear
Invalidate and set timer to nil in viewDidDisappear
Also try replacing your start timer code with this (Swift 3):
timer = Timer.scheduledTimer(timeInterval: 5, target: self, selector: #selector(self.updateIndex(_:)), userInfo: nil, repeats: true)
I am attempting to make a countdown timer that counts down from 60 seconds and then stops when it gets to 0. But for the timer keeps going into negative seconds. Any advice is appreciated. Code:
#IBOutlet var timeCounter: UILabel!
var second = 60
var timer = NSTimer()
var timerRunning = true
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
setTimer()
timerCounting()
}
func setTimer(){
second -= 1
timeCounter.text = "\(second)"
}
func timerCounting(){
if(timerRunning == true){
timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: Selector("setTimer"), userInfo: nil, repeats: true)
timerRunning = true
if second == 0 {
timerRunning = false
timer.invalidate()
}
}
}
You have to move the invalidation into the setTimer function since at its current location will never be triggered because timerCounting is only called once - in the beginning.
func setTimer(){
second -= 1
timeCounter.text = "\(second)"
if second == 0 {
timerRunning = false
timer.invalidate()
}
}
play with this in playground
import XCPlayground
XCPlaygroundPage.currentPage.needsIndefiniteExecution = true
import Foundation
#objc class C:NSObject {
var timer: NSTimer?
var second = 5
func setTimer(){
if c.second < 0 {
print("the timer fires the last time here ...")
timer?.invalidate()
} else {
print(second)
second -= 1
}
}
}
let c = C()
func timerCounting(){
c.timer = NSTimer.scheduledTimerWithTimeInterval(1, target: c, selector: Selector("setTimer"), userInfo: nil, repeats: true)
}
timerCounting()
I need launch the timer few times in sequence (one after another). And of course I need update Label with timer results.
For example, I have two periods (50 sec and 10 sec) and I need to make a series of periods: 50-10-50-10-50-10.
How can I do it?
import UIKit
class StartTimerViewController: UIViewController {
let firstPeriodTime = 50
let secondPeriodTime = 10
var currentPeriodTime: Int!
let repetitionTime = 3
var timer: NSTimer!
var timeCount = 0
#IBOutlet weak var timerLabel: UILabel!
// MARK: - IBAction method implementation
#IBAction func start(sender: AnyObject) {
// I know it's wrong... This is my question!!!!!
var i = 1
while i <= repetitionTime {
currentPeriodTime = firstPeriodTime
startTimer()
currentPeriodTime = secondPeriodTime
startTimer()
i = i + 1
}
}
// MARK: - Timer method implementation
func startTimer() {
timer = NSTimer.scheduledTimerWithTimeInterval(1, target:self, selector: "updateCounter", userInfo: nil, repeats: true)
print("timer start")
}
func updateCounter() {
if timeCount < currentPeriodTime {
timeCount++
let currentTime = Double(currentPeriodTime - timeCount)
timerLabel.text = timeString(currentTime)
}
else {
timer.invalidate()
timeCount = 0
}
}
func timeString(time:NSTimeInterval) -> String {
let minutes = Int(time) / 60
let seconds = time - Double(minutes) * 60
return String(format:"%02i:%02i",minutes,Int(seconds))
}
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
Please use the code below
#IBOutlet weak var _lblTimer: UILabel!
var timer = NSTimer()
var intValue = 0
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: "update50:", userInfo: nil, repeats: true)
}
func update50(timer : NSTimer){
intValue += 1
_lblTimer.text = intValue.description
if(intValue == 50){
intValue = 0
timer.invalidate()
self.timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: "update10:", userInfo: nil, repeats: true)
}
}
func update10(timer : NSTimer){
intValue += 1
_lblTimer.text = intValue.description
if(intValue == 10){
intValue = 0
timer.invalidate()
self.timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: "update50:", userInfo: nil, repeats: true)
}
}
My game is supposed to be stopped after 60s. But nothing happens with my timer code.
var timer = NSTimer()
var counter:Int = 60
var labelCounter:SKLabelNode = SKLabelNode()
Here is the code in my GameScene class :
func startTimer()
{
timer = NSTimer.scheduledTimerWithTimeInterval(1.0
, target: self, selector: Selector("updateTimer:"), userInfo: nil, repeats: true)
}
func updateTimer(dt:NSTimer)
{
counter--
if counter == 0 {
timer.invalidate()
removeCountDownTimerView()
} else{
labelCounter.text = "\(counter)"
}
}
func removeCountDownTimerView()
{
scene.view.paused = true
}
thank you for your insight :-)
Try something like this....
override func viewDidLoad() {
super.viewDidLoad()
//calling the wait function
self.callForWait()
}
func callForWait(){
//setting the delay time 60secs.
let delay = 60 * Double(NSEC_PER_SEC)
let time = dispatch_time(DISPATCH_TIME_NOW, Int64(delay))
dispatch_after(time, dispatch_get_main_queue()) {
//call the method which have the steps after delay.
self.stepsAfterDelay()
}
}
func stepsAfterDelay(){
//your code after delay takes place here...
}
I had this in a game. Hope it helps:
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
startGame()
}
var startTime = NSTimeInterval()
var timer = NSTimer()
var gameTime:Double = 10
func startGame() {
let aSelector : Selector = "updateTime"
timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: aSelector, userInfo: nil, repeats: true)
startTime = NSDate.timeIntervalSinceReferenceDate()
}
func updateTime() {
var currentTime = NSDate.timeIntervalSinceReferenceDate()
var elapsedTime = currentTime - startTime
var seconds = gameTime-elapsedTime
if seconds > 0 {
elapsedTime -= NSTimeInterval(seconds)
println("\(Int(seconds))")
} else {
timer.invalidate()
}
}
}