1. apk触发录音启动或录音停止按键：
public void onClick(View v) {
    switch (v.getId()) {
        case R.id.btn_Record:  //启动录音
            startRecording();
            break;
        case R.id.btn_stop:  //停止录音
            stopRecording();
            break;

        default:
            break;
    }
}

2. 创建MediaRecorder对象并初始化，启动录音： 
private void startRecording() {
        recorder = new MediaRecorder();  // 创建MediaRecorder对象
        recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
        recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
        recorder.setOutputFile(fileName);
        recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);

        try {
            recorder.prepare();
        } catch (IOException e) {
            Log.e(LOG_TAG, "prepare() failed");
        }
        //  启动录音   
        recorder.start();
 }

 private void stopRecording() {
        recorder.stop();
        recorder.release();
        recorder = null;
 }

 @Override
 public void onCreate(Bundle icicle) {
        super.onCreate(icicle);

    // 录音文件保存路径
    fileName = getExternalCacheDir().getAbsolutePath();
    fileName += "/audiorecordtest.3gp";

// 权限请求
ActivityCompat.requestPermissions(this, permissions, REQUEST_RECORD_AUDIO_PERMISSION);
}

//  权限请求
private static final int REQUEST_RECORD_AUDIO_PERMISSION = 200;    
// Requesting permission to RECORD_AUDIO
private boolean permissionToRecordAccepted = false;
private String [] permissions = {Manifest.permission.RECORD_AUDIO};

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
 switch (requestCode){
   case REQUEST_RECORD_AUDIO_PERMISSION:
   permissionToRecordAccepted  = grantResults[0] == PackageManager.PERMISSION_GRANTED;
   break;
  }
  if (!permissionToRecordAccepted ) finish();
}

manifest xml权限声明： 
<uses-permission android:name="android.permission.RECORD_AUDIO" />

3. 按照，如上步骤进行配置，可通过MediapPlayer对象api拉起音频录音。