我可以在ChangeNotifier类中使用animationController吗？

Question

现在我正在尝试重建代码。

现在的问题是动画控制器位于StatefulWidget中，因此当我转到另一页时，StatefulWidget消失了，动画控制器也无法正常工作。.

所以我想在changeNotifier类中处理动画Controller状态。

有什么解决办法吗？

----------------------------有状态类----------------- -----------

        class _PomodoroState extends State<Pomodoro> with TickerProviderStateMixin {
    
      SharedPreferences prefs;
      SettingDataHandler settingDataHandler;
      PomodoroHandler pomodoroHandler;
      AnimationController animationController;
    
      @override
      void initState() {
        super.initState();
        animationController =
            AnimationController(vsync: this, duration: Duration(milliseconds: 450));
      }
    
      @override
      void dispose() {
        super.dispose();
        animationController.dispose();
      }
    
      Future<int> _initPref() async {
        prefs = await SharedPreferences.getInstance();
        var timeData = prefs.get('timeData');
        if (timeData != null) {
          settingDataHandler.selectedTimes["Pomodoro Setting"] = timeData;
        }
    
        pomodoroHandler.pomodoroTime = settingDataHandler.selectedTimes["Pomodoro Setting"];
        pomodoroHandler.time = pomodoroHandler.pomodoroTime * 60;
    
        return 0;
      }
    
      @override
      Widget build(BuildContext context) {
        screenWidth = MediaQuery.of(context).size.width;
        settingDataHandler = Provider.of<SettingDataHandler>(context);
        pomodoroHandler = Provider.of<PomodoroHandler>(context);
    
        return Scaffold(
            body: Container(
              decoration: BoxDecoration(
                color: Colors.black54,
              ),
              width: double.infinity,
              child: Column(
                mainAxisAlignment: MainAxisAlignment.spaceBetween,
                children: <Widget>[
                  _ClockView(),
                  bottomBar()
              ],
            )
          )
        );
      }
    
      Widget bottomBar(){
        return Container(
          width: screenWidth,
          color: Colors.white,
          child: Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: <Widget>[
              Padding(
                padding: EdgeInsets.only(left: 40),
                  child: Text(pomodoroHandler.formatTime(pomodoroHandler.elapsedTime, pomodoroHandler.time), style: TextStyle(color: Colors.black54, fontSize: 30, fontWeight: FontWeight.bold),)
              ),
              _ClockButtons()
            ],
          ),
        );
      }
    
      Widget _ClockView() {
        return FutureBuilder(
          future: _initPref(),
          builder: (BuildContext context, AsyncSnapshot snapshot) {
            if (snapshot.hasData == false) {
              return CircularProgressIndicator();
            } else if (snapshot.hasError) {
              return Padding(
                  padding: const EdgeInsets.all(8.0),
                  child: Text(
                    'Error: ${snapshot.error}',
                    style: TextStyle(fontSize: 15),
                  )
              );
            }
    
            double percent = pomodoroHandler.elapsedTime / pomodoroHandler.time;
            return Padding(
              padding: EdgeInsets.only(top: 100),
              child: CircularPercentIndicator(
                  circularStrokeCap: CircularStrokeCap.round,
                  percent: percent,
                  animation: true,
                  animateFromLastPercent: true,
                  radius: 300.0,
                  lineWidth: 5.0,
                  progressColor: Colors.deepOrange,
                  center: Text(
                    pomodoroHandler.formatTime(pomodoroHandler.elapsedTime, pomodoroHandler.time),
                    style: TextStyle(
                        color: Colors.white, fontSize: 50.0, fontWeight: FontWeight.w300),
                  )
              ),
            );
          },
        );
      }
    
      Widget _ClockButtons() {
        return Row(
          children: <Widget>[StopButton(), PalyAndPauseButton()],
        );
      }
    
      Widget StopButton() {
        return IconButton(
          iconSize: 50,
          splashColor: Colors.white30,
          color: Colors.black54,
          icon: Icon(Icons.stop),
          onPressed: () => {
            pomodoroHandler.ResetTimer(),
            animationController.reverse(),
            pomodoroHandler.timer.cancel(),
            bottomSheet(),
            pomodoroHandler.endTime = formatter.format(new DateTime.now())
          },
        );
      }
    
      Widget PalyAndPauseButton() {
        return IconButton(
          iconSize: 50,
          splashColor: Colors.white30,
          icon: AnimatedIcon(
              icon: AnimatedIcons.play_pause,
              progress: animationController,
              color: Colors.black54),
          onPressed: () => {
            setState((){
              pomodoroHandler.isPlaying = !pomodoroHandler.isPlaying;
              pomodoroHandler.isPlaying ? animationController.forward() : animationController.reverse();
            }),
            HandleOnPressed()
          },
        );
      }
    
      HandleOnPressed() {
        if (pomodoroHandler.isPlaying) {
          pomodoroHandler.StartTimer(formatted, WhenTimerIsEnd);
        } else {
          pomodoroHandler.timer.cancel();
        }
      }

---------------------------- ChangeNotifier类----------------- -----------

class PomodoroHandler with ChangeNotifier {
      Timer timer;
      DateTime start;
      String startTime;
      String endTime;
      int count = 0;
      int elapsedTime = 0;
      bool isPlaying = false;
      int pomodoroTime;
      int time;
      Pomodoro pomodoro;
      TextEditingController eventController;
    
      ResetTimer() {
        time = pomodoroTime * 60;
        elapsedTime = 0;
        notifyListeners();
      }
    
      formatTime(int now, int duration) {
        String first = ((duration - now) ~/ 60).toString();
        int seconds = ((duration - now) % 60);
        String latter = (seconds < 10 ? "0" : "") + seconds.toString();
        return first + ":" + latter;
      }
    
      StartTimer(String formatted, dynamic whenTimerIsEnd()) {
        startTime = formatted;
        start = new DateTime.now();
        start = elapsedTime > 0
            ? start.subtract(Duration(seconds: elapsedTime))
            : start;
        timer = Timer.periodic(Duration(seconds: 1), (timer) {
          if (time > elapsedTime) {
            elapsedTime = DateTime.now().difference(start).inSeconds;
            print(isPlaying);
          } else {
              whenTimerIsEnd();
          }
          notifyListeners();
        });
      }
    
      StopTimer(){
        ResetTimer();
        timer.cancel();
    
      }
    
    }