Swift 错误：类 RecordSoundsViewController 没有初始化器答案

【问题标题】：Swift error : class RecordSoundsViewController has no initializersSwift 错误：类 RecordSoundsViewController 没有初始化器
【发布时间】：2015-02-25 20:14:59
【问题描述】：

class RecordSoundsViewController: UIViewController, AVAudioRecorderDelegate{

@IBOutlet weak var recordButton: UIButton!
@IBOutlet weak var recodinginProgress: UILabel!
@IBOutlet weak var stopButton: UIButton!

var audioPlayer: AVAudioPlayer!
var recordAudio: RecordedAudio!
var audioRecorder:AVAudioRecorder

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}
override func viewWillAppear(animated: Bool) {
    //hide the stop button
    stopButton.hidden = true
    recordButton.enabled = true
}

@IBAction func recordAudio(sender: UIButton) {
    recordButton.enabled = false
    stopButton.hidden = false
    recodinginProgress.hidden = false
    //TODO: Record the user"s voice
    let dirPath = NSSearchPathForDirectoriesInDomains(.DocumentDirectory,
                                                .UserDomainMask, true)[0] as String
    let currentDateTime = NSDate()
    let formatter = NSDateFormatter()
    formatter.dateFormat = "ddMMyyyy-HHmmss"
    let recordingName = formatter.stringFromDate(currentDateTime)+".wav"
    let pathArray = [dirPath, recordingName]
    let filePath = NSURL.fileURLWithPathComponents(pathArray)
    println(filePath)

    var session = AVAudioSession.sharedInstance()
    session.setCategory(AVAudioSessionCategoryPlayAndRecord, error: nil)
    audioRecorder = AVAudioRecorder(URL: filePath, settings: nil, error: nil)
    audioRecorder.delegate = self
    audioRecorder.meteringEnabled = true
    audioRecorder.prepareToRecord()
    audioRecorder.record()

}

我不知道我做错了什么。我的错误即将出现在我的课堂上。

它说

类 RecordSoundsViewController 在 RecordSoundsViewController 上没有初始化器：UIViewController, AVAudioRecorderDelegate{

【问题讨论】：

标签： xcode multithreading swift exc-bad-instruction

【解决方案1】：

编译器的错误消息有点糟糕。您看到错误的原因是您有一个没有默认值的属性。

在 Swift 中，所有值都需要有一个默认值，除非它是可选的。在你的情况下，它是这个属性：var audioRecorder:AVAudioRecorder

在您的情况下，我会将这个属性设为可选：var audioRecorder:AVAudioRecorder? 并确保在使用时检查 nil。或者让它成为一个隐式展开的可选（如果你知道总会有一个值）：var audioRecorder:AVAudioRecorder!

【讨论】：