nstimer

I am creating and firing a NSTimer with: ncTimer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(handleTimer:) userInfo:nil repeats:YES]; [ncTimer fire]; AND - (void)handleTimer:(NSTimer *)chkTimer { // do stuff } I am retaining my timer with: @property (nonatomic, retain) NSTimer *ncTimer; For some reason the timer is not repeating. It is firing once only and than never again. You can't just assign to the timer that you have put as a property in your header. This should work: self.ncTimer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector

I have a NSTimer object that I need to invalidate if a user taps on a button or if they exit a view. So I have: [myNSTimer invalidate]; inside my button handler and inside viewWillDisappear . If user taps on a button and then exists a view the app throws an exception because myNSTimer has already been invalidated. What I need to do in the viewWillDisappear method is check if the myNSTimer has been invalidated or not. How do I do that? I've tried: if(myNSTimer != nil) [myNSTimer invalidate]; but that didn't work. Once you invalidate the timer, simply call release on it (assuming you've retained

I'm just wondering, is there a better, more efficient function to use than NSTimer? I have a NSTimer code like this on my ViewDidLoad function: [NSTimer scheduledTimerWithTimeInterval:900.0f target:self selector:@selector(methodToRun) userInfo:nil repeats:YES]; With the function methodToRun: -(void)methodToRun { if(currentTime == presetTime) { //do something } } This works fine but the problem is, this eats up a lot of memory and I am getting memory warnings. So, what's a better, more efficient and less memory consuming way of triggering my methodToRun continuously to check if the currentTime

I want to stop this timer and then restart it from where I stopped it. secondsTimer = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(addSeconds), userInfo: nil, repeats: true) Below, it was suggested I shouldn't increment a timer in my timer handler. Why not? For example, using GCD timer: func countSeconds() { secondsTimer = DispatchSource.makeTimerSource(queue: .main) secondsTimer?.schedule(deadline: .now(), repeating: 1.0) secondsTimer?.setEventHandler { [weak self] in self?.addSeconds() } } @objc func addSeconds() { seconds += 1 } func startGame() { secondsTimer?

I have some web service data in my app that needs to be updated every 3 minutes. I had tried out a few approaches but got a really good piece of advise in here last week, I should not build a new thread every 3 minutes and then subsequently try and dealloc and synchronize all the different parts so that I avoided memory bug. Instead I should have a "worker thread" that was always running, but only did actual work when I asked it too (every 3 minutes). As my small POC works now, I spawn a new thread in the applicationDidFinishLaunching method. I do this like so: [NSThread

I am trying to get a countdown timer to a specific date. I use: -(void) viewWillAppear:(BOOL)animated { NSString *str =@"12/27/2013"; NSDateFormatter *formatter = [[NSDateFormatter alloc]init]; [formatter setDateFormat:@"MM/dd/yyyy"]; NSDate *date = [formatter dateFromString:str]; NSTimeInterval numberOfSecondsUntilSelectedDate = [date timeIntervalSinceNow]; NSInteger numberOfDays = numberOfSecondsUntilSelectedDate / 86400; startTime = [[NSDate date] retain]; secondsLeft = numberOfDays; NSLog(@"number%f", numberOfSecondsUntilSelectedDate); [self countdownTimer]; } - (void)updateCounter:

I'm trying to have the UIPageViewController navigate through the pages for every 5 seconds. How to do this in Swift? Is there any way to explicitly call viewControllerAfterViewController ? var timer = NSTimer.scheduledTimerWithTimeInterval(5, target: self, selector: Selector("update"), userInfo: nil, repeats: true) func update() -> UIViewController { // can u please tell me what to add here } func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController? { var index = (viewController as

Following this question , and more specifically, this comment : because retain (aka strong reference) cycles in the common case where the timer's target is also its owner I am wondering why dealloc isn't a good place to invalidate an NSTimer . I remember profiling my app without auto-repeating NSTimer invalidation and then with invalidation in dealloc , and the memory correctly freed. Is dealloc working differently in the latest iOS? Isn't in fact your overridden dealloc called prior to any NSObject deallocation? What is dealloc even used for, then? If not manually deallocating the respective