code: public void start() {
          if (null != recorder && prepared && !recording) {
              initWakeLock();
              wannaCancel = false;
              try {
                  recorder.start();
                  recording = true;
                  if (null != mOnRecordPreparedListener) {
                      mOnRecordPreparedListener.onStartRecording();
                  }
              } catch (Exception e) {
                  e.printStackTrace();
                  if (null != mOnRecordPreparedListener) {
                      mOnRecordPreparedListener.onStartFailed();
                  }
              }
          }
      }
docs: 开始录制