“尝试 AVAudioSession.sharedInstance().setCategory”仅在设备上返回 nil

Question

try AVAudioSession.sharedInstance()
                  .setCategory(AVAudioSessionCategoryPlayback,
                               with: AVAudioSessionCategoryOptions(rawValue: UInt(UInt8(AVAudioSessionCategoryOptions.defaultToSpeaker.rawValue)
                                                                                | UInt8(AVAudioSessionCategoryOptions.allowAirPlay.rawValue)
                                                                                | UInt8(AVAudioSessionCategoryOptions.allowBluetooth.rawValue)
                                                                                | UInt8(AVAudioSessionCategoryOptions.allowBluetoothA2DP.rawValue))))

返回错误：

域=NSOSStatusErrorDomain 代码=-50“（空）”

Answer 1

对于将来发现此问题的任何人来说，这里就是解决方案。如果您更改AVAudioSessionCategoryPlayback为AVAudioSessionCategoryPlayAndRecord这样，它仅适用于设备：

try AVAudioSession.sharedInstance()
                  .setCategory(AVAudioSessionCategoryPlayAndRecord,
                               with: AVAudioSessionCategoryOptions(rawValue: UInt(UInt8(AVAudioSessionCategoryOptions.defaultToSpeaker.rawValue)
                                                                                | UInt8(AVAudioSessionCategoryOptions.allowAirPlay.rawValue)
                                                                                | UInt8(AVAudioSessionCategoryOptions.allowBluetooth.rawValue)
                                                                                | UInt8(AVAudioSessionCategoryOptions.allowBluetoothA2DP.rawValue))))