Nested Navigation Example

main.dart

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

GlobalKey<NavigatorState> navigatorKey = GlobalKey();

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

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

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text("Ok")),
    body: Navigator(
      key: navigatorKey,
      onGenerateRoute: (route) {
        return PageRouteBuilder(
          pageBuilder: (context, _, __) {
            switch(route.name) {
              case "a":
                return A();
              case "b":
                return B();
              default:
                return C();
            }
          },
        );
      }
    ),
    );
  }
}

class A extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Center(child: InkWell(onTap: () => navigatorKey.currentState.pushReplacementNamed('b'),child: Text("A, go to B")),);
  }
}


class B extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Center(child: InkWell(onTap: () => navigatorKey.currentState.pushReplacementNamed('c'),child: Text("B, go to C")),);
  }
}


class C extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Center(child: InkWell(onTap: () => navigatorKey.currentState.pushReplacementNamed('a'),child: Text("C, go to A")),);
  }
}