Flutter，如何刷新Navigator.pop上的最后一页状态

class AppState extends ChangeNotifier {
  int counter = 0;

  void incrementCounter() {
    counter++;
    notifyListeners();
  }
}

class LastPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ChangeNotifierProvider<AppState>(
      create: (_) => AppState(),
      child: Consumer<AppState>(
        builder: (context, appState, _) {
          return Scaffold(
            appBar: AppBar(
              title: Text('Last Page'),
            ),
            body: Center(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Text('Counter: ${appState.counter}'),
                  RaisedButton(
                    child: Text('Increment'),
                    onPressed: () {
                      appState.incrementCounter();
                    },
                  ),
                ],
              ),
            ),
          );
        },
      ),
    );
  }
}

class PreviousPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Previous Page'),
      ),
      body: Center(
        child: RaisedButton(
          child: Text('Go to Last Page'),
          onPressed: () async {
            final appState = Provider.of<AppState>(context, listen: false);
            await Navigator.push(
              context,
              MaterialPageRoute(builder: (context) => LastPage()),
            );
            // 在Navigator.pop之后，可以通过appState获取最后一页的状态
            print('Counter from Last Page: ${appState.counter}');
          },
        ),
      ),
    );
  }
}