Hello à tous,
Je suis confronté à un soucis sur ma première app que je suis en train de créer pour une webradio. Tout semble bien fonctionner dans le global sauf le petit Switch qui va activer ou pas un autoplay au lancement de l’app, mais je suis confronté à une erreur fatale. 
//
// ViewController.swift
// xx
//
// Created by Didier on 15/08/2017.
// Copyright © 2017 xxxxxxxxxxxx. All rights reserved.
//
import UIKit
import AVKit
import AVFoundation
import Alamofire
var player : AVPlayer!
var playerRunning = false
let SWITCH_USER_DEFAULTS_KEY:String = "AUTOPLAY"
class ViewController: UIViewController {
@IBOutlet weak var playButton: UIButton!
@IBOutlet weak var ui_currentArtist: UILabel!
@IBOutlet weak var ui_currentSong: UILabel!
@IBOutlet weak var ui_currentJacket: UIImageView!
@IBOutlet weak var ui_autoplaySwitch: UISwitch!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
getcurrentSong()
Timer.scheduledTimer(timeInterval: 3.0, target: self, selector: #selector(getcurrentSong), userInfo: nil, repeats: true)
playButton.backgroundColor = .clear
playButton.layer.cornerRadius = playButton.frame.height / 2
playButton.layer.borderWidth = 1
playButton.layer.borderColor = UIColor.black.cgColor
//playButton.contentEdgeInsets = UIEdgeInsets(top: 8, left: 8, bottom: 8, right: 8)
do {
try AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback)
print("AVAudioSession Category Playback OK")
do {
try AVAudioSession.sharedInstance().setActive(true)
print("AVAudioSession is Active")
} catch let error as NSError {
print("------>" + error.localizedDescription)
}
} catch let error as NSError {
print("------>" + error.localizedDescription)
}
// LANCEMENT DE LA RADIO AU DEMARRAGE DE L'APP EN FONCTION DE LA PREFERENCE UTILISATEUR
if UserDefaults.standard.bool(forKey: SWITCH_USER_DEFAULTS_KEY) == true {
playPlayer()
ui_autoplaySwitch.setOn(true, animated: false)
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
@IBAction func autoplaySwitch(_ sender: UISwitch) {
let userDefaults = UserDefaults.standard
userDefaults.set(sender.isOn, forKey: SWITCH_USER_DEFAULTS_KEY)
}
@IBAction func playRadio() {
if (playerRunning) {
stopPlayer()
} else {
playPlayer()
}
}
func playPlayer() {
let url = "http://xxxxxxxxxxxxxxxxxx.net/xxxxxxxxxxx-128.mp3"
player = AVPlayer(url: URL(string: url)!)
player.volume = 1.0
player.rate = 1.0
player.play()
playButton.setImage(UIImage(named: "stop"), for: .normal)
playButton.setTitleColor(UIColor.blue, for: .selected)
playerRunning = !playerRunning
}
func stopPlayer() {
player.pause()
playButton.setImage(UIImage(named: "play"), for: .normal)
playerRunning = !playerRunning
}
@objc func getcurrentSong() {
Alamofire.request("http://xxxxxxxxxxxx.fr/ajax/current").validate().responseJSON {
(response: DataResponse<Any>) in
if response.result.isSuccess {
if let songs = response.result.value as? [String:AnyObject] {
if (songs["current"] != nil) {
let currentArtist = songs["current"]!["artist"] as? String
let currentTrack = songs["current"]!["track"] as? String
let urlOfCurrentJacket = songs["current"]!["cover"] as? String
self.ui_currentArtist.text = String(currentArtist!)
self.ui_currentSong.text = String(currentTrack!)
self.ui_currentJacket.downloadedFrom(link: urlOfCurrentJacket!)
}
}
}
}
}
}
extension UIImageView {
func downloadedFrom(url: URL, contentMode mode: UIViewContentMode = .scaleAspectFit) {
contentMode = mode
URLSession.shared.dataTask(with: url) { (data, response, error) in
guard
let httpURLResponse = response as? HTTPURLResponse, httpURLResponse.statusCode == 200,
let mimeType = response?.mimeType, mimeType.hasPrefix("image"),
let data = data, error == nil,
let image = UIImage(data: data)
else { return }
DispatchQueue.main.async() { () -> Void in
self.image = image
}
}.resume()
}
func downloadedFrom(link: String, contentMode mode: UIViewContentMode = .scaleAspectFit) {
guard let url = URL(string: link) else { return }
downloadedFrom(url: url, contentMode: mode)
}
}
Le soucis que je rencontre semble venir de la ligne :
ui_autoplaySwitch.setOn(true, animated: false)
L’erreur :
fatal error: unexpectedly found nil while unwrapping an Optional value
Je ne comprend pas pourquoi j’obtiens cette erreur. Si quelqu’un voulait éclairer ma lanterne… 
N’hésitez pas à me donner vos commentaires sur le code si besoin, si j’aurais pu faire plus efficace ou je ne sais pas 
