NSTimer not calling Method

Question

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
 .......

This is not even remotely related to Xcode. – Mar 20 '13 at 16:43 — , Mar 20 '13 at 16:43

score 23 · Accepted Answer · edited Jun 20 '20 at 09:12

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)

Ohhh... I must have selected the wrong method in the xcode suggestion thingawhatever. I meant to call the second one. — sinθ, Mar 20 '13 at 16:44
I've done it too, and I've seen this same question several times. — progrmr, Mar 20 '13 at 17:06

FreeAsInBeer · Answer 2 · 2013-03-20T16:51:23.927

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];

score 2 · Answer 3 · answered Mar 20 '13 at 16:44

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];

score 1 · Answer 4 · answered Mar 20 '13 at 16:44

1

You can use:

[[NSRunLoop mainRunLoop] addTimer:timer forMode:NSDefaultRunLoopMode];

answered Mar 20 '13 at 16:44

Anoop Vaidya

46,283
15
111
140

NSTimer not calling Method

4 Answers4

From the docs Scheduling Timers in Run Loops

Swift Code