全局监听路由堆栈变化

void main() {
  runApp(MyApp());
}

RouteObserver<PageRoute> routeObserver = RouteObserver<PageRoute>();

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      ...
      navigatorObservers: [routeObserver],home: HomePage(),);
  }
}

class ARouteObserverDemo extends StatefulWidget {
  @override
  _RouteObserverDemoState createState() => _RouteObserverDemoState();
}

class _RouteObserverDemoState extends State<ARouteObserverDemo> with RouteAware {

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    routeObserver.subscribe(this,ModalRoute.of(context));
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Container(
        alignment: Alignment.center,child: RaisedButton(
          child: Text('A RouteObserver'),onPressed: () {
            Navigator.of(context).pushNamed('/BRouteObserver');
          },),);
  }

  @override
  void dispose() {
    super.dispose();
    routeObserver.unsubscribe(this);
  }

  @override
  void didPush() {
    final route = ModalRoute.of(context).settings.name;
    print('A-didPush route: $route');
  }

  @override
  void didPopNext() {
    final route = ModalRoute.of(context).settings.name;
    print('A-didPopNext route: $route');
  }

  @override
  void didPushNext() {
    final route = ModalRoute.of(context).settings.name;
    print('A-didPushNext route: $route');
  }

  @override
  void didPop() {
    final route = ModalRoute.of(context).settings.name;
    print('A-didPop route: $route');
  }

}

flutter: A-didPush route: /ARouteObserver

flutter: A-didPushNext route: /ARouteObserver
flutter: B-didPush route: /BRouteObserver

flutter: A-didPopNext route: /ARouteObserver
flutter: B-didPop route: /BRouteObserver

class MyRouteObserver<R extends Route<dynamic>> extends RouteObserver<R> {
  @override
  void didPush(Route route,Route previousRoute) {
    super.didPush(route,previousRoute);
    print('didPush route: $route,previousRoute:$previousRoute');
  }

  @override
  void didPop(Route route,Route previousRoute) {
    super.didPop(route,previousRoute);
    print('didPop route: $route,previousRoute:$previousRoute');
  }

  @override
  void didReplace({Route newRoute,Route oldRoute}) {
    super.didReplace(newRoute: newRoute,oldRoute: oldRoute);
    print('didReplace newRoute: $newRoute,oldRoute:$oldRoute');
  }

  @override
  void didRemove(Route route,Route previousRoute) {
    super.didRemove(route,previousRoute);
    print('didRemove route: $route,previousRoute:$previousRoute');
  }

  @override
  void didStartUserGesture(Route route,Route previousRoute) {
    super.didStartUserGesture(route,previousRoute);
    print('didStartUserGesture route: $route,previousRoute:$previousRoute');
  }

  @override
  void didStopUserGesture() {
    super.didStopUserGesture();
    print('didStopUserGesture');
  }
}

void main() {
  runApp(MyApp());
}

MyRouteObserver<PageRoute> myRouteObserver = MyRouteObserver<PageRoute>();

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',navigatorObservers: [myRouteObserver],initialRoute: '/A',home: APage(),);
  }
}

flutter: didPush route: MaterialPageRoute<dynamic>(RouteSettings("/B",来自A),animation: AnimationController#6d429(▶ 0.000; for MaterialPageRoute<dynamic>(/B))),previousRoute:MaterialPageRoute<dynamic>(RouteSettings("/A",null),animation: AnimationController#e60f7(⏭ 1.000; paused; for MaterialPageRoute<dynamic>(/A)))