如何在Flutter中实现多个倒计时进度条？

import 'package:flutter/material.dart';

class Timer {
  int totalTime;
  int currentTime;
  double progress;

  Timer({this.totalTime}) {
    this.currentTime = totalTime;
    this.progress = 1.0;
  }
}

class CountdownTimerWidget extends StatefulWidget {
  final Timer timer;

  CountdownTimerWidget({this.timer});

  @override
  _CountdownTimerWidgetState createState() => _CountdownTimerWidgetState();
}

class _CountdownTimerWidgetState extends State<CountdownTimerWidget>
    with TickerProviderStateMixin {
  AnimationController _animationController;
  Animation<double> _animation;

  @override
  void initState() {
    super.initState();
    _animationController = AnimationController(
      vsync: this,
      duration: Duration(seconds: widget.timer.totalTime),
    );
    _animation = Tween<double>(begin: 1.0, end: 0.0).animate(_animationController)
      ..addListener(() {
        setState(() {
          widget.timer.progress = _animation.value;
          widget.timer.currentTime =
              (widget.timer.totalTime * widget.timer.progress).round();
        });
      });

    _animationController.reverse(from: 1.0);
  }

  @override
  void dispose() {
    _animationController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      height: 10.0,
      child: LinearProgressIndicator(
        value: widget.timer.progress,
        backgroundColor: Colors.grey[300],
        valueColor: AlwaysStoppedAnimation<Color>(Colors.blue),
      ),
    );
  }
}

class MultipleCountdownTimersWidget extends StatelessWidget {
  final List<Timer> timers;

  MultipleCountdownTimersWidget({this.timers});

  @override
  Widget build(BuildContext context) {
    return Column(
      children: timers.map((timer) {
        return CountdownTimerWidget(timer: timer);
      }).toList(),
    );
  }
}

void main() {
  List<Timer> timers = [
    Timer(totalTime: 10),
    Timer(totalTime: 20),
    Timer(totalTime: 30),
  ];

  runApp(
    MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Multiple Countdown Timers'),
        ),
        body: Center(
          child: MultipleCountdownTimersWidget(timers: timers),
        ),
      ),
    ),
  );
}