private async void Timer_Tick(object sender, object e)
        {
            AudioRecorder _audioRecorder_old = this._audioRecorder;

            //停止后切换对象立即继续接力录音
            i_audioRecorder++;
            this._audioRecorder = pool_audioRecorder[i_audioRecorder % 2];

            this._audioRecorder.Record();
            _audioRecorder_old.StopRecording();

            pool_audioRecorder[(i_audioRecorder + 1) % 2] = new AudioRecorder();

            //保存文件
            string filename = "speechfile" + i_audioRecorder.ToString() + ".wav";
            await _audioRecorder_old.SaveAudioToFile(filename);

            _audioRecorder_old.Close();


            //timer.Stop();


            string text = "";

            try
            {
                text = await SpeechRecognizeAsync(filename);
            }
            catch (Exception ex)
            {
                string str = ex.Message;
            }

            //this.text_note.Text += text;

            OnReceiveText(this, text); //产生事件
            // 识别完成后删除文件
            DelWavFile(filename);
        }