(iOS) Action when music file stops - ios

Question

When I open a view the music starts playing using AVFoundation and then when it finishes, how do I create an action when it stops? So when the music file finishes, I want the "Pause" button turn into "Play". I know already how to change the text programmatically by using btnPausePlay.setTitle("Pause", forState: UIControlState.Normal)but how do I create the function when the music stops playing?
Note: I'm using swift

Answer 1

You can use delegate functions for that and here is your complete code:
import UIKit
import AVFoundation
class ViewController: UIViewController, AVAudioPlayerDelegate {
var player = AVAudioPlayer()
#IBOutlet weak var musicSlider: UISlider!
#IBOutlet weak var btnPausePlay: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
musicSlider.value = 0.0
music()
}
func updateMusicSlider(){
musicSlider.value = Float(player.currentTime)
}
#IBAction func sliderAction(sender: AnyObject) {
player.stop()
player.currentTime = NSTimeInterval(musicSlider.value)
player.play()
}
func music(){
var audioPath = NSBundle.mainBundle().pathForResource("1", ofType: "mp3")!
var error : NSError? = nil
player = AVAudioPlayer(contentsOfURL: NSURL(string: audioPath), error: &error)
musicSlider.maximumValue = Float(player.duration)
var timer = NSTimer.scheduledTimerWithTimeInterval(0.05, target: self, selector: Selector("updateMusicSlider"), userInfo: nil, repeats: true)
player.delegate = self
if error == nil {
player.delegate = self
player.prepareToPlay()
player.play()
}
}
//This delegate method will call when your player finish playing.
func audioPlayerDidFinishPlaying(player: AVAudioPlayer!, successfully flag: Bool)
{
btnPausePlay.setTitle("Play", forState: .Normal)
}
}
And HERE is your sample project for more Info.