Xylophone App

• To play music using swift:

import AVFoundation

var player: AVAudioPlayer?

func playSound() {
    guard let url = Bundle.main.url(forResource: "soundName", withExtension: "mp3") else { return }

    do {
        try AVAudioSession.sharedInstance().setCategory(.playback, mode: .default)            
        try AVAudioSession.sharedInstance().setActive(true)

        /* The following line is required for the player to work on iOS 11. Change the file type accordingly*/
        player = try AVAudioPlayer(contentsOf: url, fileTypeHint: AVFileType.mp3.rawValue)

        /* iOS 10 and earlier require the following line:
        player = try AVAudioPlayer(contentsOf: url, fileTypeHint: AVFileTypeMPEGLayer3) */

        guard let player = player else { return }

        player.play()

    } catch let error {
        print(error.localizedDescription)
    }
}

• Code found on stack overflow
• Simpler code:

import UIKit
import AVFoundation

class ViewController: UIViewController {
    
    var player: AVAudioPlayer!

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    @IBAction func keyPressed(_ sender: UIButton) {
        playSound()
    }
    
    func playSound() {
        let url = Bundle.main.url(forResource: "C", withExtension: "wav")
        player = try! AVAudioPlayer(contentsOf: url!)
        player.play()
                
    }
}

Attaching Multiple Buttons to the same Action

• Once you have linked one of the button to your code, then where your function starts there is a + when you hover over the line number.
• Click and drag it to the other buttons

How to distinguish which button was pressed?

• sender.currentTitle can be used to get the title of the button

Delay?

DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) { // number of seconds
    // your code here
}