`NSDictionary`不能隱式轉換爲`[NSObject的：AnyObject]`

Question

我有這樣的功能：

func audioRecordingSettings() -> NSDictionary { 

     return [ 
      AVFormatIDKey : kAudioFormatMPEG4AAC as NSNumber, 
      AVSampleRateKey : 16000.0 as NSNumber, 
      AVNumberOfChannelsKey : 1 as NSNumber, 
      AVEncoderAudioQualityKey : AVAudioQuality.Medium.rawValue as NSNumber 
     ] 
    } 

然後我定義的另一個：

func startRecordingAudio() { 

    var error: NSError? 

    let audioRecordingURL = self.audioRecordingPath() 

    audioRecorder = AVAudioRecorder(URL: audioRecordingURL, settings: audioRecordingSettings(), error: &error) 
    //Here the error comes. 
} 

它要求我以後添加爲[NSObject: AnyObject]audioRecordingSetthings()，我不認爲這是正確的解決方案。 因爲當我在另一個class中調用startRecordingAudio()時，它與Unexpectedly found nil崩潰。

Answer 1

你只需要在AVAudioRecorderDelegate添加audioRecordingSettings() as [NSObject : AnyObject]：

AVAudioRecorder(URL: audioRecordingURL, settings: audioRecordingSettings() as [NSObject : AnyObject], error: &error) 

另外我想你的方法更改爲：

func audioRecordingSettings() -> [NSObject : AnyObject] { 

    return [ 
     AVFormatIDKey : kAudioFormatMPEG4AAC, 
     AVSampleRateKey : 16000.0, 
     AVNumberOfChannelsKey : 1, 
     AVEncoderAudioQualityKey : AVAudioQuality.Medium.rawValue 
    ] 
} 

Answer 2

您需要檢查"AVAudioRecorder"初始化它規定：

init!(URL url: NSURL!, settings: [NSObject : AnyObject]!, error outError: NSErrorPointer) 

所以，你需要轉換設置爲[NSObject : AnyObject]。