How can I make a Swift 3.0 timer that calculates in hh:mm:ss:ms

Question

I followed DuncanC's solution in Swift timer in milliseconds. Code below:

startTime = NSDate.timeIntervalSinceReferenceDate
Timer.scheduledTimer(timeInterval: 0.02,
                                           target: self,
                                           selector: Selector(("advanceTimer:")),
                                           userInfo: nil,
                                           repeats: true)


func advanceTimer(timer: Timer)
{
    //Total time since timer started, in seconds
    self.time = NSDate.timeIntervalSinceReferenceDate - startTime
    //The rest of your code goes here
}

Xcode recommended I change NSDate.timeIntervalSinceReferenceDate() to NSDate.timeIntervalSinceReferenceDate and startTime: NSTimeInterval to startTime: TimeInterval for Swift 3.0. My code produces the error:

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[MyGame.GameScene advanceTimer:]: unrecognized selector sent to instance

thanks for the correction. I managed to get the formatting from http://stackoverflow.com/questions/28872450/conversion-from-nstimeinterval-to-hour-minutes-seconds-milliseconds-in-swift — iGetIt, Nov 11 '16 at 15:21

Nirav D · Accepted Answer · 2016-11-11T14:57:08.790

3

In Swift 3 Selector syntax is changed, now you need to pass first parameter label with your action, your selector should be like #selector(self.advanceTimer(timer:)).

Timer.scheduledTimer(timeInterval: 0.02,
                     target: self,
                     selector: #selector(self.advanceTimer(timer:)),
                     userInfo: nil,
                     repeats: true)

edited Nov 11 '16 at 14:57

answered Nov 11 '16 at 14:51

Nirav D

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5

You've posted a similar answer several times. You really should be closing these questions as duplicates. – rmaddy Nov 11 '16 at 15:00
@rmaddy Next time i will sure raise flag.:) – Nirav D Nov 11 '16 at 15:28

score 1 · Answer 2 · answered Nov 11 '16 at 14:58

advanceTimer(timer:) should be declared differently according to Swift API Design Guidelines, You should use Swift's native Date instead of NSDate and selector syntax has changed so your code would now be written like this:

startTime = NSDate.timeIntervalSinceReferenceDate
Timer.scheduledTimer(timeInterval: 0.02,
                     target: self,
                     selector: #selector(advanceTimer),
                     userInfo: nil,
                     repeats: true)

func advanceTimer(_ timer: Timer)
{
    //Total time since timer started, in seconds
    self.time = NSDate.timeIntervalSinceReferenceDate - startTime
    //The rest of your code goes here
}

Also, Timer has new closure based methods, so your the whole thing can now be reduced to:

startTime = NSDate.timeIntervalSinceReferenceDate
Timer.scheduledTimer(withTimeInterval: 0.02, repeats: true) { timer in
    //Total time since timer started, in seconds
    self.time = NSDate.timeIntervalSinceReferenceDate - startTime
    //The rest of your code goes here
}

+1 for the new closure-based timers. I wish Apple had added that in iOS 4, when they first introduced blocks. Not sure why it took so long. I didn't discover this addition until a few days ago. (Note that if your app needs to run on iOS versions before iOS 10 then you can't use closure-based timers. :( — Duncan C, Nov 11 '16 at 19:52

How can I make a Swift 3.0 timer that calculates in hh:mm:ss:ms

2 Answers2