startTimer method

void startTimer()

Implementation

void startTimer() {
  stopTimer();
  startSeconds = currentSeconds;
  startTime = DateTime.now().millisecondsSinceEpoch;
  updateTime = DateTime.now().millisecondsSinceEpoch;
  timer = Timer.periodic(const Duration(seconds: 1), (timer) async {
    onChangeSecond();
  });
}