Delay execution iOS app

Question

I'm looking for a method that is an easy and straightforward way to delay execution for a number of frames in an iOS app, is this possible at all ?

It's not clear exactly what you are asking, but maybe `NSTimer scheduledTimerWithTimeInterval` suits your needs? — bengoesboom, Jun 06 '13 at 18:38
Careful with your terminology, I think you may be coming from another platform when you talk about "delaying for a number of **frames**". What you mean is delaying for an interval in time. — Daniel, Jun 06 '13 at 18:53

score 10 · Answer 1 · edited May 23 '17 at 12:24

Depending on the complexity of what you're doing, this small snippet could suffice:

double delayInSeconds = 2.0;
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC));
dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
    //code to be executed on the main queue after delay
});

Otherwise you could look into NSTimer to schedule some code to be executed. You can even repeat once or many times.

Can be used like this for example:

[NSTimer scheduledTimerWithTimeInterval:5.0 
                                 target:self 
                               selector:@selector(myMethod) 
                               userInfo:nil 
                                repeats:NO];

For a great answer with a lot more info on how to use it, check out this post and of course, check out the documentation.

score 2 · Answer 2 · answered Jun 06 '13 at 18:43

2

If you mean by some constant time, the common way to do this is to use a NSTimer to fire at some time in the future, or to use dispatch_after(), which can dispatch a block to either the main queue or a background one at some time in the future.

answered Jun 06 '13 at 18:43

David H

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score 2 · Answer 3 · answered Jun 06 '13 at 18:48

David is correct. Here's some code for how I use NSTimer.

-(void)startAnimating {
    [NSTimer scheduledTimerWithTimeInterval:.3 target:self selector:@selector(animateFirstSlide) userInfo:nil repeats:NO];
    self.pageTurner = [NSTimer scheduledTimerWithTimeInterval:6.0 target:self selector:@selector(turnPages) userInfo:nil repeats:YES];
}

-(void)animateFirstSlide {
    [self animateSlideAtIndex:0];
}

-(void)stopPageTurner {
    [self.pageTurner invalidate];
}

Thank you all for your reply's, i have plenty to experiment with now. — Balthatczar, Jun 06 '13 at 21:38

score 1 · Accepted Answer · edited Dec 02 '13 at 06:30

1

You can use [NSTimer scheduledTimerWithTimeInterval: target: selector:] method or also you can use inbuilt method as wait(time_in_seconds);.
Hope this will help you.

edited Dec 02 '13 at 06:30

Dilip

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answered Jun 06 '13 at 19:13

Ponting

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Delay execution iOS app

4 Answers4