UISlider to control AVAudioPlayer

Shouldn’t be a problem – just set the slider to continuous and set the max value to your player’s duration after loading your sound file.

Edit

I just did this and it works for me…

- (IBAction)slide {
    player.currentTime = slider.value;
}

- (void)updateTime:(NSTimer *)timer {
    slider.value = player.currentTime;
}

- (IBAction)play:(id)sender {
    NSURL *url = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"sound.caf" ofType:nil]];
    NSError *error;
    player = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:&error];
    if (!player) NSLog(@"Error: %@", error);
    [player prepareToPlay];
    slider.maximumValue = [player duration];
    slider.value = 0.0;
    
    [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(updateTime:) userInfo:nil repeats:YES];  
    [player play];
}

The slider is configured in IB, as is a button to start playing.

Swift 3.0 Update:

var player: AVAudioPlayer!
var sliderr: UISlider!

@IBAction func play(_ sender: Any) {
    var url = URL(fileURLWithPath: Bundle.main.path(forResource: "sound.caf", ofType: nil)!)
    var error: Error?
    do {
        player = try AVAudioPlayer(contentsOf: url)
    }
    catch let error {
    }
    if player == nil {
        print("Error: \(error)")
    }
    player.prepareToPlay()
    sliderr.maximumValue = Float(player.duration)
    sliderr.value = 0.0
    Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(self.updateTime), userInfo: nil, repeats: true)
    player.play()
}

func updateTime(_ timer: Timer) {
    sliderr.value = Float(player.currentTime)
}

@IBAction func slide(_ slider: UISlider) {
    player.currentTime = TimeInterval(slider.value)
}