问如何中断设备音频以播放声音，然后让设备音频在iOS上继续播放

EN

func playFile(atPath path:String) {
    self.player?.delegate = nil
    self.player?.stop()
    let fileURL = URL(fileURLWithPath: path)
    guard let p = try? AVAudioPlayer(contentsOf: fileURL) else {return} // nicer
    self.player = p
    // error-checking omitted
    
    // switch to playback category while playing, interrupt background audio
    try? AVAudioSession.sharedInstance().setCategory(.playback, mode:.default)
    try? AVAudioSession.sharedInstance().setActive(true)
    
    self.player.prepareToPlay()
    self.player.delegate = self
    let ok = self.player.play()
    print("interrupter trying to play \(path): \(ok)")
}

func audioPlayerDidFinishPlaying(_ player: AVAudioPlayer, successfully flag: Bool) { // *
    let sess = AVAudioSession.sharedInstance()
    // this is the key move
    try? sess.setActive(false, options: .notifyOthersOnDeactivation)
    // now go back to ambient
    try? sess.setCategory(.ambient, mode:.default)
    try? sess.setActive(true)
    delegate?.soundFinished(self)
}

self.observer = NotificationCenter.default.addObserver(forName:
    AVAudioSession.interruptionNotification, object: nil, queue: nil) {
        [weak self] n in
        guard let self = self else { return } // legal in Swift 4.2
        let why = n.userInfo![AVAudioSessionInterruptionTypeKey] as! UInt
        let type = AVAudioSession.InterruptionType(rawValue: why)!
        switch type {
        case .began:
            print("interruption began:\n\(n.userInfo!)")
        case .ended:
            print("interruption ended:\n\(n.userInfo!)")
            guard let opt = n.userInfo![AVAudioSessionInterruptionOptionKey] as? UInt else {return}
            let opts = AVAudioSession.InterruptionOptions(rawValue: opt)
            if opts.contains(.shouldResume) {
                print("should resume")
                self.player.prepareToPlay()
                let ok = self.player.play()
                print("bp tried to resume play: did I? \(ok as Any)")
            } else {
                print("not should resume")
            }
        @unknown default:
            fatalError()
        }
}

try! audioSession.setActive(false, options: .notifyOthersOnDeactivation)

// I play the audio using this AVAudioPlayer
var player: AVAudioPlayer?

// Implement playing a sound
func playSound() {
    
    // Local url for me, but you could configure as you need
    guard let url = Bundle.main.url(forResource: "se_1",
                                    withExtension: "wav")
    else { return }
    
    do {
        // Set the category to playback to interrupt the current audio
        try AVAudioSession.sharedInstance().setCategory(.playback,
                                                        mode: .default)
        
        try AVAudioSession.sharedInstance().setActive(true)
        
        player = try AVAudioPlayer(contentsOf: url)
        
        // This is to know when the sound has ended
        player?.delegate = self
        
        player?.play()
        
    } catch let error {
        print(error.localizedDescription)
    }
}

extension AVAudioInterruptVC: AVAudioPlayerDelegate {
    
    func audioPlayerDidFinishPlaying(_ player: AVAudioPlayer,
                                     successfully flag: Bool) {
        
        do {
            
            // When the sound has ended, notify other apps
            // You can do this where ever you want, I just show the
            // example of doing it when the audio has ended
            try AVAudioSession.sharedInstance()
                .setActive(false, options: [.notifyOthersOnDeactivation])
        }
        catch {
            print(error)
        }
        
    }
}