Playing Random Audio File using Swift

Question

I keep on getting the following error when I use the "Shake Gesture" in the iPhone simulator:

Fatal error: unexpectedly found nil while unwrapping an Optional value

Here is my relevant code:

import UIKit
import AVFoundation

class ViewController: UIViewController {

    var soundFiles = ["kidLaughing", "pewpew", "pingas", "runningfeet"]
    var player: AVAudioPlayer = AVAudioPlayer()

    override func motionEnded(motion: UIEventSubtype, withEvent event: UIEvent) {
        if event.subtype == .MotionShake {
            var randomSoundFile = Int(arc4random_uniform(UInt32(soundFiles.count)))
            var fileLocation = NSString(string:NSBundle.mainBundle().pathForResource("sounds/" + soundFiles[randomSoundFile], ofType: "mp3")!)

            var error: NSError? = nil

            player = AVAudioPlayer(contentsOfURL: NSURL(string: fileLocation), error: &error)

            player.play()
        }
    }
}

I have a folder named sounds with 4 mp3 files located in it. The error is happening on this line of code:

  var fileLocation = NSString(string:NSBundle.mainBundle().pathForResource("sounds/" + soundFiles[randomSoundFile], ofType: "mp3")!)

I have tried everything I can think of to get this to work but nothing I have tried has worked. Any help is appreciated!

Answer 1

This means that there is a value that is nil when you are asserting that it isn't. Separate the crashing line into its components and find out exactly what is nil:

var soundFile = soundFiles[randomSoundFile]
var path = "sounds/" + soundFile
var fullPath = NSBundle.mainBundle().pathForResource(path, ofType: "mp3")!
var fileLocation = NSString(string:fullPath) // fyi, this line is pointless, fullPath is already a string

I would guess that it is crashing on the pathForResource line because the file cannot actually be found. Make sure you are actually linking the 'sounds' directory into your bundle.

Answer 2

    let path = NSBundle.mainBundle().pathForResource("Ring", ofType: "mp3")
    let fileURL = NSURL(fileURLWithPath: path!)
    play = AVAudioPlayer(contentsOfURL: fileURL, error: nil)
    play.prepareToPlay()
    play.delegate = self
    play.play()

It is just an example

Answer 3

//You can try this one also for random sound play.

import UIKit
import AVFoundation
class GameScene: SKScene {
var pinballVoiceArray = ["BS_PinballBounce1.mp3", "BS_PinballBounce2.mp3", "BS_PinballBounce3.mp3"]
var randomIndex = 0
override func didMoveToView(view: SKView) {
    //use the random sound function
    playPinballSound()
   }
func playPinballSound () {
    randomIndex = Int(arc4random_uniform(UInt32(pinballVoiceArray.count)))
    var selectedFileName = pinballVoiceArray[randomIndex]
    runAction(SKAction.playSoundFileNamed(selectedFileName, waitForCompletion: false))
    }
}

// Call the Function playPinballSound where you would like to play random sound.

Answer 4

I had the same problem. What I did was just "Add files to MyProject..." and add the whole sounds folder. Once Swift had the reference to this folder, there was no need to include the folder in the pathForResource parameter.

Answer 5

I had the same problem.

I solved it by choosing "create folder references" instead of "Create Groups", when copying the folder with sound files to the project.

Hope this works for you too. I am very new to Swift and the whole iOS programming, so I don't know what exactly happens behind the scenes.