java - Android mediarecorder stop 在无效状态下调用：4

Question

大家好，我正在创建一个通话录音应用程序，当我试图停止通话录音时，Java 中的调试控制台说：“MediaRecorder stop 在无效状态下调用：4”我用谷歌搜索了很多，但我什么也找不到可以帮我 ！我已经在使用 RECORD_AUDIO 和 WRITE_EXTRENAL_STORAGE 权限！这是我的代码的一部分：

private class PhoneCallListener extends PhoneStateListener {
    private boolean isPhoneCalling = false;
    @SuppressWarnings("deprecation")
    @Override
    public void onCallStateChanged(int state, final String incomingNumber) {
        // TODO Auto-generated method stub
        super.onCallStateChanged(state, incomingNumber);
        String path = Environment.getExternalStorageDirectory()+"/callrec/";
        final MediaRecorder recorder = new MediaRecorder();
        recorder.setAudioSource(MediaRecorder.AudioSource.VOICE_CALL);
        recorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
        recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
        recorder.setOutputFile(path+"/TEST00000000011110.M4A");
        if (TelephonyManager.CALL_STATE_RINGING == state) {

        }
        if (TelephonyManager.CALL_STATE_OFFHOOK == state) {
            isPhoneCalling = true;
            try {
                recorder.prepare();
                recorder.start();
            } catch (Exception e) {
            }
            }
        if (TelephonyManager.CALL_STATE_IDLE == state) {
            if (isPhoneCalling) {
                try {
                    recorder.stop();
                    recorder.reset();
                    recorder.release();
                } catch (Exception e) {
                    // TODO: handle exception
                }
                Intent i = getBaseContext().getPackageManager()
                        .getLaunchIntentForPackage(
                                getBaseContext().getPackageName());
                i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                startActivity(i);
                isPhoneCalling = false;
                }

        }
    }
}