ios - 耳机插入时如何录制卡拉OK？

Question

我想做一个卡拉OK应用程序，一切都很完美，没有耳机插件。[.MixWithOthers, .DefaultToSpeaker])

我想将其设置为 [.MixWithOthers, .DefaultToHeadPhones])

但没有这样的功能。但是，插入耳机后，混音录音不起作用。这是我的示例代码：https ://github.com/genedelisa/AVFoundationRecorder/blob/master/AVFoundation%20Recorder/RecorderViewController.swift

func setSessionPlayback() { 让会话：AVAudioSession = AVAudioSession.sharedInstance()

    do {
        try session.setCategory(AVAudioSessionCategoryPlayAndRecord)
    } catch let error as NSError {
        print("could not set session category")
        print(error.localizedDescription)
    }
    do {
       // try session.setActive(true)
    } catch let error as NSError {
        print("could not make session active")
        print(error.localizedDescription)
    }
}

func setSessionPlayAndRecord()
{
    let session = AVAudioSession.sharedInstance()
    do {

      //  var setCategoryErr: NSError? = nil
      //  var activationErr: NSError? = nil
        //Set the general audio session category
        try session.setCategory(AVAudioSessionCategoryPlayAndRecord)
        var doChangeDefaultRoute: UInt32 = 1
        do {
            try session.setCategory(AVAudioSessionCategoryPlayAndRecord,
                                    withOptions:AVAudioSessionCategoryOptions.DefaultToSpeaker)
        }
        catch let error {

        }

        //Activate the customized audio session
         try session.setActive(true)

    } catch let error as NSError {
        print("could not set session category")
        print(error.localizedDescription)
    }
    do {
       // try session.setActive(true)
    } catch let error as NSError {
        print("could not make session active")
        print(error.localizedDescription)
    }
}