timer inside init method calling itself twice after its interval of 10seconds.Can anybody please tell me how to stop this ? Thanks in advance.
- (id)init {
if (self = [super init]) {
timer=[NSTimer scheduledTimerWithTimeInterval:10 target:self selector:#selector(serviceCalling) userInfo:nil repeats:YES];
//[timer fire];
//NSDefaultRunLoopMode
//[[NSRunLoop currentRunLoop] addTimer:timer forMode:NSRunLoopCommonModes];
}
return self;
}
-(void)serviceCalling{
NSLog(#"Inside");
}
Are you constructing this object more than once? Given the code you have posted, that's the only explanation (unless you are confusing the repeated one 10 seconds later).
Put an NSLog in the init.
Related
I have an NSTimer that I want to be stopped when I leave my vViewVontroller:
The timer is in a method that I call from viewWillAppear :
- (void) myMehtod
{
//timer = [[NSTimer alloc] init];
// appel de la methode chaque 10 secondes.
timer = [NSTimer scheduledTimerWithTimeInterval:10.0f
target:self selector:#selector(AnotherMethod) userInfo:nil repeats:YES];
//self.timerUsed = timer;
}
I call the method stopTimer in viewWillDisappear
- (void) stopTimer
{
[timer invalidate];
timer = nil;
}
PS: I tried the answer of user1045302 in this question but it didn't work:
How to stop NSTimer
The source of the problem probably is that myMehtod is called twice or more times.
Since the method does not invalidate existing timers before setting up the new one you actually have several timers ticking at the same time.
Fix is easy: invalidate old timers before setting up a new one:
- (void)myMehtod
{
[timer invalidate];
timer = [NSTimer scheduledTimerWithTimeInterval:10.0f
target:self
selector:#selector(anotherMethod)
userInfo:nil
repeats:YES];
}
I have gone through many sites but still no answer.
I have a method suppose void xyz(), which will get called automatically from a View Controller after every 3 seconds.
I have no idea what to use, do I have to use NSThread or PerformSelector.
Call this method from ViewDidLoad method.ViewDidLoad will when your view will be appear in iPhone device or Simulator.
[NSTimer scheduledTimerWithTimeInterval:3.0f target:self selector:#selector(runMethod) userInfo:nil repeats:YES];
-(void)runMethod
{
}
Something like this
-(void)xyz{
[self performSelectorInBackground:#selector(xyz) withObject:nil];
}
- (void)viewDidLoad {
[self performSelector:#selector(xyz) withObject:nil afterDelay:0.3];
}
Use NSTimer
NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:3.0f target:self selector:#selector(xyz) userInfo:nil repeats:YES];
You should use NSTimer as mentioned by #mokujin.
Please visit https://developer.apple.com/library/mac/documentation/Cocoa/Reference/Foundation/Classes/NSTimer_Class/Reference/NSTimer.html
[self performSelectorInBackground:#selector(method) withObject:nil];
-(void)method
{
timer1 = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:#selector(getLastImageName1) userInfo:nil repeats:YES];
runLoop = [NSRunLoop currentRunLoop];
[runLoop addTimer:timer1 forMode:NSRunLoopCommonModes];
[runLoop run];
}
-(void)viewdidunload
{
[timer1 invalidate];
timer1=nil;
}
I start Timer in HomeViewController even I invalidate, it keeps running in OtherViewController. What is wrong with my code?
First of all, when you're overriding life cycle methods, you should include a call to the super version of that method.
Second of all, Objective-C is case sensitive, so even if your app would try to call the life-cycle even, viewDidUnload, your method would simply never be called because that's what you titled your method.
Third of all, viewDidUnload was deprecated in iOS 6.0 and shouldn't be used at all by this point unless you're going way out of your way to support backward compatibility. It will never be called in iOS 6.0 and greater.
If you want the timer to stop when the user navigates away from the current view, you'll want something like this:
- (void)viewDidDisappear:(BOOL)animated {
[super viewDidDisappear:animated];
if (timer1.isValid) {
[timer1 invalidate];
}
timer1 = nil;
}
If you're looking for something else, you'll need to elaborate on what it is you want to accomplish exactly.
If you ARE working on a pre-iOS 6.0 project, for whatever reason, the reason your method isn't being called is at least in part because it is spelled wrong. Again, Objective-C is case sensitive. Your method name should be spelled viewDidUnload.
For future reference, the question shouldn't really be "why isn't my timer invalidating?" You should have start by using breakpoints or NSLog statements to determine whether or not your method, viewdidunload, which tries to invalidate the timer even fires. When you find out it's not being called, do a search to ask "How come viewdidunload isn't called?" Then you'll go fix the capitalization problem and the problem will (probably) remain, so do some more research. And if at the end, you still can't figure it out, as a worst case scenario, the post question should be "how come viewdidunload isn't called?"
timer1 = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:#selector(getLastImageName1:) userInfo:nil repeats:YES];
set colon for function in selector
-(void) getLastImageName1 :(NSTimer*)timer1
{
//Do your all process and invalidate after completion
[timer1 invalidate];
}
or if you want to remove timer after moving to next view controller use how #nhgrif mentioned
- (void)viewDidDisappear:(BOOL)animated
{
[timer1 invalidate];
}
[self performSelector:#selector(method) withObject:nil afterDelay:0.0];
-(void)method
{
timer1 = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:#selector(getLastImageName1) userInfo:nil repeats:YES];
runLoop = [NSRunLoop currentRunLoop];
[runLoop addTimer:timer1 forMode:NSRunLoopCommonModes];
[runLoop run];
}
- (void)viewDidDisappear:(BOOL)animated
{
[super viewDidDisappear:animated];
[timer1 invalidate];
timer1=nil;
}
There is no need to add the timer (again) on the main run loop. Or is it necessary for You to run it also in commonModes? For me it was never necessary.
From the NSTimer Documentation:
scheduledTimerWithTimeInterval:invocation:repeats:
Creates and returns a new NSTimer object and schedules it on the
current run loop in the default mode.
Since the NSRunLoop Documentation points out that you can add timer on several run loop modes, maybe this is the problem.
addTimer:forMode:
Discussion You can add a timer to multiple input modes. While running
in the designated mode, the receiver causes the timer to fire on or
after its scheduled fire date. Upon firing, the timer invokes its
associated handler routine, which is a selector on a designated
object.
Also I don't get why you are invoking the timer creation with performSelector?
I just wrote a minimalistic sample. thats totally working!
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
self.timer = [NSTimer scheduledTimerWithTimeInterval:1.0f target:self selector:#selector(doWork:) userInfo:Nil repeats:YES];
}
- (void)viewDidDisappear:(BOOL)animated{
[self.timer invalidate];
[super viewDidDisappear:animated];
}
- (void) doWork:(id) userInfo
{
NSLog(#"Working again");
}
Hope this helps.
-(void)viewDidUnload is a delegate which fires on memory warning only and is deprecated after iOS 6. It will also never fire on the simulator.
Stop timer in
- (void)viewWillDisappear:(BOOL)animated
or in
- (void)viewDidDisappear:(BOOL)animated
This question already has answers here:
How do I use NSTimer?
(6 answers)
Closed 9 years ago.
I am making a Simon Says app to learn more about Objective C.
My SimonSaysViewController has 4 buttons. Their image needs to change accordingly when the pattern is being shown to the user.
A fixed interval timer will be absolutely fine.
I just cannot seem to find an example.
I basically would want a sort of setup like:
TimerTicked callback when I can do the image swapping logic.
Ideally, the TimerTicked method would be a method of my SimonSaysViewController.
How would this be done?
Thanks
NSTimer is your friend! Add an NSTimer property to your SimonSaysViewController.
#property (strong, nonatomic) NSTimer *tickTockTimer;
Depending on when you want the timer to start, you'll want to set up the timer then. Say you wanted the timer to start when the view first appears:
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
self.tickTockTimer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:#selector(timerFired:) userInfo:nil repeats:YES];
}
Then implement the timerFired method and do what you need there.
- (void)timerFired:(NSTimer *)timer {
//change the image.
}
Don't forget to invalidate the timer when you are done.
- (void) viewWillDisappear:(BOOL)animated {
[super viewWillDisappear:animated];
[self.timer invalidate];
self.timer = nil;
}
This kind of thing usually works for me
NSDate *fireDate = [NSDate dateWithTimeIntervalSinceNow:2.0]; // 2 sec from now
NSTimer *self.timer = [[NSTimer alloc] initWithFireDate:fireDate interval:5 target:self selector:#selector(timerDidTick) userInfo:nil repeats:YES]; // fire 5 sec apart
NSRunLoop *runLoop = [NSRunLoop currentRunLoop];
[runLoop addTimer:self.timer forMode:NSDefaultRunLoopMode];
This question already has answers here:
NSTimer timerWithTimeInterval: not working
(4 answers)
Closed 9 years ago.
I have an NSTimer that should call a method every second, but it doesn't seem to be calling it at all.
This is how I declare the timer:
[NSTimer timerWithTimeInterval:1.0 target:self selector:#selector(fadeManager:) userInfo:nil repeats:YES];
This is the method it calls:
-(void) fadeManager: (NSTimer*) timer{
NSLog(#"IT'S WORKING!");
self.playHead += .1; // keeps track of where they are in full track
if (self.playHead >= self.wait && ![player isPlaying]) { // checks if wait is over
[player play];
}
if (self.playHead >= self.duration + self.startTime && [player isPlaying]) { // checks if full duration is over
[player pause];
[self reset];
}
int fadeOutArea = self.startTime + self.duration - self.fadeOut;
int fadeInArea = self.startTime + self.fadeIn;
if (self.playHead <= fadeInArea && [player volume] < relativeVolume) { // checks if fadingIn.
[self fadeInIncriment];
}
if (self.playHead >= fadeOutArea && [player volume] > 0) {
[self fadeOutIncriment];
}
}
The code was not working so I put the NSLog in as well as a break point. It seems that it is never being called. Why is this? Does it matter that I declared the method in the .m file like this:
#import <AVFoundation/AVFoundation.h>
#interface CueMusic ()
- (void) delayFadeOut: (AVAudioPlayer*) dFade;
- (void) fadeInIncriment;
- (void) fadeOutIncriment;
- (void) fadeManager: (NSTimer*) timer; // <--------
- (void) start;
#end
#implementation CueMusic
.......
Either use
NSTimer *timer = [NSTimer timerWithTimeInterval:1.0 target:self selector:#selector(fadeManager:) userInfo:nil repeats:YES];
[[NSRunLoop mainRunLoop] addTimer:timer forMode:NSDefaultRunLoopMode];
or
//schedules the timer
[NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:#selector(fadeManager:) userInfo:nil repeats:YES];
From the docs Scheduling Timers in Run Loops
Use the scheduledTimerWithTimeInterval:invocation:repeats: or scheduledTimerWithTimeInterval:target:selector:userInfo:repeats: class method to create the timer and schedule it on the current run loop in the default mode.
Use the timerWithTimeInterval:invocation:repeats: or timerWithTimeInterval:target:selector:userInfo:repeats: class method to create the timer object without scheduling it on a run loop. (After creating it, you must add the timer to a run loop manually by calling the addTimer:forMode: method of the corresponding NSRunLoop object.)
Swift Code
Either
let timer: NSTimer = NSTimer(timeInterval: 1.0, target: self, selector: "fadeManager:", userInfo: nil, repeats: true)
NSRunLoop.mainRunLoop().addTimer(timer, forMode: NSDefaultRunLoopMode)
Or
//schedules the timer
NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: "fadeManager:", userInfo: nil, repeats: true)
Your problem is that when using timerWithTimeInterval:target:selector:userInfo:repeats:, the resulting timer does not automatically get added to the run loop. I would recommend using scheduledTimerWithTimeInterval:target:selector:userInfo:repeats: instead, which performs this step for you.
If you prefer to use timerWithTimeInterval:target:selector:userInfo:repeats: then you need to manually add the timer to the current run loop. To do this, call NSRunLoop's addTimer:forMode: method. Documentation
[[NSRunLoop currentRunLoop] addTimer:tTimer forMode: NSDefaultRunLoopMode];
You need to fire the timer.
You can do it by adding it to a thread:
NSTimer *timer = [NSTimer timerWithTimeInterval:1.0 target:self selector:#selector(fadeManager:) userInfo:nil repeats:YES];
[[NSRunLoop mainRunLoop] addTimer:timer forMode:NSDefaultRunLoopMode];
or calling
[timer fire];
You can use:
[[NSRunLoop mainRunLoop] addTimer:timer forMode:NSDefaultRunLoopMode];