How to run NSTimer in background and sleep in iOS?

Question

I found a lot of post in stackoverflow about NSTimer run in background.

However I didn\'t find any solution.

In my app , I play sound in background

Answer 1

I know this post is relatively old but I recently ran into this problem and was having some trouble figuring it out. This is the solution I came up with as of Swift 5. It uses a combination of the RunLoop and Timer classes, with information about them in the provided links below.

Using timers

• https://developer.apple.com/documentation/foundation/timer

Using run loops


• https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/Multithreading/RunLoopManagement/RunLoopManagement.html#//apple_ref/doc/uid/10000057i-CH16-SW1

• https://developer.apple.com/documentation/foundation/runloop

Sample code:

class AMSleepTimerUtil: NSObject {
    static let shared = AMSleepTimerUtil()
    fileprivate var sleepTimer: Timer?
    
    /// Initialize the timer to trigger a function to execute after a duration of time
    /// - Parameter seconds: the time delay until the selector function executes
    /// - Returns: true if sleep timer were successfully initialized
    func createTimerToStopMusic(at seconds: TimeInterval) -> Bool {
        let fireAtDate = Date(timeIntervalSinceNow: seconds)
        stopSleepTimer()
        
        self.sleepTimer = Timer(fireAt: fireAtDate,
                                interval: 0,
                                target: self,
                                selector: #selector(pauseMusic),
                                userInfo: nil,
                                repeats: false)
        guard let sleepTimer = sleepTimer else { return false }
        RunLoop.main.add(sleepTimer, forMode: .common)
        
        return true
    }
    
    func pauseMusic() {
        guard let audioPlayer = AMNowPlayingViewController.sharedInstance()?.audioPlayer else { return }
        
        audioPlayer.pause()
    }
    
    /// Used to reset the sleep timer before initializing a new timer if the user clicks the "Set Timer" multiple times
    func stopSleepTimer() {
        if sleepTimer != nil {
            sleepTimer?.invalidate()
            sleepTimer = nil
        }
    }
    
    func sleepTimerIsActive() -> Bool {
        return self.sleepTimer != nil
    }
}