/** 初始化百度的配置 */
 private void initBaiduConfiguration(Context con) {
   if (recognitionClient == null) {
     recognitionClient = VoiceRecognitionClient.getInstance(con);
     recognitionClient.setTokenApis(
         BaiDuVoiceConfiguration.API_KEY, BaiDuVoiceConfiguration.SECRET_KEY);
   }
 }