Swift: utilisation de 'self' dans l'appel de méthode avant que super.init initialise l'erreur d'auto-compilation

Question

J'ai créé une classe personnalisée qui gère l'enregistrement/la lecture audio et j'ai mis un Protocol dans cette classe. J'ai implémenté la Protocol dans une classe UIViewController et j'ai appelé ma méthode setDelegate pour ma classe AudioHelper.

Je reçois une erreur de compilation liée à ma init(). Vous ne savez pas exactement comment vous débarrasser de l'erreur:

use of 'self' in method call 'setupAudioSession' before super.init initializes self

override init() {
        setupAudioSession()
        super.init()
    }

Comment résoudre cette erreur? Et pourquoi dois-je remplacer init ()?

Ma classe AudioHelper

import Foundation
import AVFoundation

class AudioHelper: NSObject, AVAudioRecorderDelegate {

    var audioSession: AVAudioSession?
    var audioRecorder: AVAudioRecorder?
    var delegate: AudioRecorderProtocol?

    class var sharedInstance: AudioHelper {

        struct Static {
            static var instance: AudioHelper?
            static var token: dispatch_once_t = 0
        }

        dispatch_once(&Static.token) {
            Static.instance = AudioHelper()
        }

        return Static.instance!
    }

    override init() {
        setupAudioSession()
        super.init()
    }

    func setDelegate(delegate: AudioRecorderProtocol) {
        self.delegate = delegate
    }

    func setupAudioSession() {
        audioSession = AVAudioSession.sharedInstance()
        audioSession?.setCategory(AVAudioSessionCategoryPlayAndRecord, error: nil)
        audioSession?.setActive(true, error: nil)
    }

    func createAudioMessageDirectory() {
        let fm = NSFileManager.defaultManager()
        if !fm.fileExistsAtPath(GlobalVars.kAudioMessageDirectory) {
            var error: NSError?
            if !fm.createDirectoryAtPath(GlobalVars.kAudioMessageDirectory, withIntermediateDirectories: true, attributes: nil, error: &error) {
                println("Unable to create audio message directory: \(error)")
            }
        }
    }

    // MARK: Recording

    func beginRecordingAudio() {
        createAudioMessageDirectory()
        var filepath =  GlobalVars.kAudioMessageDirectory.stringByAppendingPathComponent("audiofile.aac")
        var url = NSURL(fileURLWithPath: filepath)

        var recordSettings = [
            AVFormatIDKey: kAudioFormatMPEG4AAC,
            AVSampleRateKey: 8000.0,
            AVNumberOfChannelsKey: 1,
            AVEncoderBitRateKey: 12800,
            AVLinearPCMBitDepthKey: 16,
            AVEncoderAudioQualityKey: AVAudioQuality.Max.rawValue
        ]

        println("Recorded Audio Message Saved: \(url!)")

        var error: NSError?
        audioRecorder = AVAudioRecorder(URL: url, settings: recordSettings as [NSObject : AnyObject], error: &error)

        if error == nil {
            if audioRecorder != nil {
                audioRecorder!.delegate = self
                audioRecorder!.record()
            }
        }
        else {
            println(error!.localizedDescription)
        }
    }

    func stopRecordingAudio() {
        if audioRecorder != nil {
            audioRecorder!.stop()
        }
    }

    func handleRecordAudioButtonLongPressGestureForState(state: UIGestureRecognizerState) {
        if state == UIGestureRecognizerState.Ended {
            stopRecordingAudio()
            delegate?.onRecordAudioStop()
        }
        else if state == UIGestureRecognizerState.Began {
            beginRecordingAudio()
            delegate?.onRecordAudioStop()
        }
    }

    func audioRecorderDidFinishRecording(recorder: AVAudioRecorder!, successfully flag: Bool) {
        println("Record Audio Success: \(flag)")
        delegate?.onRecordAudioFinished()
    }

    func audioRecorderEncodeErrorDidOccur(recorder: AVAudioRecorder!, error: NSError!) {
        println("Record Audio Encode Error: \(error.localizedDescription)")
    }

    // MARK: Playback

    func playAudioMessageFromUrl(messageId: String) {
        if let url = NSURL(string: GlobalVars.kUrlAudioMessage + messageId) {
            if let data = NSData(contentsOfURL: url) {
                var error: NSError? = nil
                let audioPlayer = AVAudioPlayer(data: data, error: &error)

                if error == nil {
                    if audioPlayer != nil {
                        audioPlayer.numberOfLoops = 0
                        audioPlayer.volume = 1.0
                        audioPlayer.prepareToPlay()
                        audioPlayer.play()
                    }
                }
                else {
                    println("Audio playback error: \(error?.localizedDescription)")
                }
            }
        }
    }

}

protocol AudioRecorderProtocol {
    func onRecordAudioStart()
    func onRecordAudioStop()
    func onRecordAudioFinished()
}

Mon UIViewController qui implémente le protocole (découpez le code superflu)

class ChatViewController: UIViewController, UITableViewDelegate, UITableViewDataSource, AudioRecorderProtocol {

    let audioHelper = AudioHelper.sharedInstance

    let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate

    override func viewDidLoad() {
        super.viewDidLoad()

//        addDemoMessages()

        setupGestureRecognizer()
        setupKeyboardObserver()
        setupViews()
        setupTableView()
        audioHelper.setDelegate(self)
    }

    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)
        getUsersFromDb()
        getMessagesFromDb()
    }

    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)
        setCurrentVC()
        tableView.reloadData()

        if partnerUserId != nil && !db.doesUserExist(partnerUserId!) {
            HttpPostHelper.profileGet(userId: partnerUserId!)
        }

        requestMessagesFromServer()
    }

    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        ViewHelper.scrollTableViewToBottom(tableView)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func handleRecordAudioButtonHold(sender: UILongPressGestureRecognizer) {
        audioHelper.handleRecordAudioButtonLongPressGestureForState(sender.state)
    }

    func onRecordAudioStart() {
        dispatch_async(dispatch_get_main_queue(), {
            ViewHelper.showToast(NSLocalizedString("RECORDING", comment: ""))
            self.recordAudioButton.imageView!.image = UIImage(named: "RecordAudioClicked")
        })
    }

    func onRecordAudioStop() {
        dispatch_async(dispatch_get_main_queue(), {
            self.recordAudioButton.imageView!.image = UIImage(named: "RecordAudio")
        })
    }

    func onRecordAudioFinished() {
        HttpPostHelper.messageAudio(partnerUserId: partnerUserId)
    }

    func playAudioFromUrl(sender: UIButton) {
        let messageId = messages[sender.tag].id
        audioHelper.playAudioMessageFromUrl(messageId)
    }

}

Answer 1

Il suffit de le placer sous super.init ()

L'objet doit d'abord être initialisé par super classe, puis vous pouvez effectuer votre initialisation personnalisée.

Alors comme:

override init() {
    super.init()
    setupAudioSession()
}