Swift - Play a Sound

Beispiele

Xylophone

//
//  ViewController.swift
//  Xylophone
//
//  Created by Angela Yu on 28/06/2019.
//  Copyright © 2019 The App Brewery. All rights reserved.
//

import UIKit
import AVFoundation
import Dispatch

class ViewController: UIViewController {

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

    @IBAction func keyPressed(_ sender: UIButton) {
        
        
        let soundName:String = sender.currentTitle!
        // Note: currentTitle is defined as type optional string,
        // meaning there are cases when no title exists (value = nil)
        // by adding ! we say "don't worry - we checked that the input
        // is guaranteed a string. Another way to be safe would be a guard:
        // guard let soundName:String = sender.currentTitle else {return}
        // a guard checks the value and would go to the else function
        // and therefore return in this case if the value is nil
        
        self.playAudioFile(soundName:soundName)
        
        sender.alpha = 0.5
        
        // Delay code execution for 0.2 seconds
        DispatchQueue.main.asyncAfter(deadline: .now() + 0.2) {
            // Code to be executed after the delay
            sender.alpha = 1.0
        }
    }
    
    var audioPlayer: AVAudioPlayer?
    
    func playAudioFile(soundName:String) {
        guard let url = Bundle.main.url(forResource: soundName, withExtension: "wav") else { return }

        do {
            // Change defaults to category playback (play sound even if phone is silenced)
            try AVAudioSession.sharedInstance().setCategory(AVAudioSession.Category.playback)
            try AVAudioSession.sharedInstance().setActive(true)

            audioPlayer = try AVAudioPlayer(
                contentsOf: url,
                fileTypeHint: AVFileType.wav.rawValue
            )

            guard let audioPlayer = audioPlayer else { return }
            audioPlayer.play()

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

    

}