Use the below code. It will work But keep in mind that it must only be called if our timer is in running mode else the application will get crashed. – (void)viewWillDisappear:(BOOL)animated { //BEFORE DOING SO CHECK THAT TIMER MUST NOT BE ALREADY INVALIDATED //Always nil your timer after invalidating so that //it does not … Read more
You could avoid the retain cycle to begin with by, e.g., aiming the timer at a StatusUpdate object that holds a non-retained (weak) reference to your controller, or by having a StatusUpdater that is initialized with a pointer your controller, holds a weak reference to that, and sets up the timer for you. You could … Read more
You need to invalidate it and recreate it. You can then use an isPaused bool to keep track of the state if you have the same button to pause and resume the timer: var isPaused = true var timer = NSTimer() @IBAction func pauseResume(sender: AnyObject) { if isPaused{ timer = NSTimer.scheduledTimerWithTimeInterval(0.1, target: self, selector: Selector(“somAction”), … Read more
Use NSTimer NSTimer* myTimer = [NSTimer scheduledTimerWithTimeInterval: 60.0 target: self selector: @selector(callAfterSixtySecond:) userInfo: nil repeats: YES]; After each 60.0 second , iOS will call the below function -(void) callAfterSixtySecond:(NSTimer*) t { NSLog(@”red”); }
For anyone else that ends up here: To determine if a UIView is onscreen somewhere, rather than checking superview != nil, it is better to check if window != nil. In the former case, it is possible that the view has a superview but that the superview is not on screen: if (view.window != nil) … Read more
The NSTimer class is a bit awkward to use; rather than separating the creation/destruction from the start/stop, it’s all rolled together. In other words the timer starts as soon as it’s created and stops as soon as it’s destroyed. You therefore need to use the existence of the NSTimer object as a flag to indicate … Read more
Could also be a threading problem: if [NSThread isMainThread] is false then start the timer like this: dispatch_async(dispatch_get_main_queue(), ^{ timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(tick:) userInfo:nil repeats:YES]; })
You don’t have to use Selector: @IBAction func startButton(sender: AnyObject) { myTimer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: “updateTimer:”, userInfo: nil, repeats: true) } Also, the timer passes itself to the selected method, so you can invalidate it inside the method if you need: func updateTimer(timer: NSTimer) { timeLabel.text = String(Counter++) timer.invalidate() } Or if the … Read more