问重置AVAudioEngine

EN

class ViewController: UIViewController {

@IBOutlet weak var sassSwitch: UISwitch!
@IBOutlet weak var chipSwitch: UISwitch!

@IBAction func sassAction(_ sender: UISwitch) {
    chipSwitch.setOn(false, animated: true)
}
@IBAction func chipSwitch(_ sender: UISwitch) {
    sassSwitch.setOn(false, animated: true)
}


///Playback Engine
private let audioEngine = AVAudioEngine()

///Player's Nodes
private let pitchPlayer = AVAudioPlayerNode()
private let timePitch = AVAudioUnitTimePitch()

///Audio Files to be played
private var audioFile1 = AVAudioFile()
private var audioFile2 = AVAudioFile()

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    if let filePath = Bundle.main.path(forResource: "PeteNope", ofType:
        "mp3") {
        let filePathURL = URL(fileURLWithPath: filePath)

        setPlayerFile(filePathURL)

    }

    if let filePath2 = Bundle.main.path(forResource: "Law_WOW", ofType:
        "mp3") {
        let filePath2URL = URL(fileURLWithPath: filePath2)

        setPlayerFile2(filePath2URL)

    }
}

private func setPlayerFile(_ fileURL: URL) {
    do {
        let file = try AVAudioFile(forReading: fileURL)

        self.audioFile1 = file


    } catch {
        fatalError("Could not create AVAudioFile instance. error: \(error).")
    }
}

private func setPlayerFile2(_ fileURL: URL) {
    do {
        let file = try AVAudioFile(forReading: fileURL)

        self.audioFile2 = file


    } catch {
        fatalError("Could not create AVAudioFile instance. error: \(error).")
    }
}


@IBAction func sound1Play(_ sender: UIButton) {
    if sassSwitch.isOn {
        timePitch.pitch = -300
        timePitch.rate = 0.5
        audioEngine.attach(pitchPlayer)
        audioEngine.attach(timePitch)

        audioEngine.connect(pitchPlayer, to: timePitch, format: audioFile1.processingFormat)
        audioEngine.connect(timePitch, to: audioEngine.outputNode, format: audioFile1.processingFormat)
        pitchPlayer.scheduleFile(audioFile1, at: nil, completionHandler: nil)

        // Start the engine.
        do {
            try audioEngine.start()
        } catch {
            fatalError("Could not start engine. error: \(error).")
        }

        pitchPlayer.play()

    } else if chipSwitch.isOn {
        timePitch.pitch = +500
        timePitch.rate = 2.0
        audioEngine.attach(pitchPlayer)
        audioEngine.attach(timePitch)

        audioEngine.connect(pitchPlayer, to: timePitch, format: audioFile1.processingFormat)
        audioEngine.connect(timePitch, to: audioEngine.outputNode, format: audioFile1.processingFormat)
        pitchPlayer.scheduleFile(audioFile1, at: nil, completionHandler: nil)

        // Start the engine.
        do {
            try audioEngine.start()
        } catch {
            fatalError("Could not start engine. error: \(error).")
        }

        pitchPlayer.play()

    } else {
        timePitch.pitch = +0
        timePitch.rate = 1.0
        audioEngine.attach(pitchPlayer)
        audioEngine.attach(timePitch)

        audioEngine.connect(pitchPlayer, to: timePitch, format: audioFile1.processingFormat)
        audioEngine.connect(timePitch, to: audioEngine.outputNode, format: audioFile1.processingFormat)
        pitchPlayer.scheduleFile(audioFile1, at: nil, completionHandler: nil)

        // Start the engine.
        do {
            try audioEngine.start()
        } catch {
            fatalError("Could not start engine. error: \(error).")
        }
        pitchPlayer.play()
    }

}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}


}