Swift: super.init ifadesinden önce yöntem çağrısında 'self' kullanımı kendi kendine derleme hatasını başlatır

Question

Ses kaydına/oynatmaya işleyen ve bu sınıfa bir Protocol koyan özel bir sınıf yaptım. UIViewController sınıfında Protocol'u uyguladı ve AudioHelper sınıfım için setDelegate yöntemimi çağırdım.

init() ile ilgili bir derleme hatası alıyorum. Tam olarak emin nasıl hata kurtulmak için:

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

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

Nasıl bu hatayı gidermek? Ve neden init() 'i geçersiz kılmalıyım?

Benim AudioHelper sınıf

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() 
} 

protokolünü uygulayan

Benim UIViewController

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

Sadece

) (super.init altına yerleştirin (dışsal kodu kesip) Nesnenin ilk önce süper sınıf tarafından başlatılması gerekiyor ve sonra bunu yapabilirsiniz r özel başlatma.

Yani şöyle:

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