An example of routing

routes.dart

import 'dart:async';
import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Flutter Demo',
      theme: new ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: new MyHomePage(),
      routes: <String, WidgetBuilder>{
        '/ScreenA': (BuildContext context) => new ScreenA(),
        '/ScreenB': (BuildContext context) => new ScreenB(),
        '/ScreenC': (BuildContext context) => new ScreenC(),
      },
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key}) : super(key: key);

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

class _MyHomePageState extends State<MyHomePage> {
  bool _loading;

  Future<String> checkPreferences() async {
    await new Future.delayed(new Duration(seconds: 1));
    return '/ScreenA';
    // return null; // Test what happens if no state is found
  }

  @override
  void initState() {
    super.initState();

    _loading = true;
    checkPreferences().then((route) {
      setState(() {
        _loading = false;
        if (route?.isNotEmpty == true) {
          Navigator.of(context).pushReplacementNamed(route);
        }
      });
    });
  }

  @override
  Widget build(BuildContext context) {
    final NavigatorState nav = Navigator.of(context);

    final List<Widget> children = [];
    if (_loading) {
      children.add(new Center(child: new Text("Loading")));
    } else {
      children.addAll(<Widget>[
        new MaterialButton(
          child: new Center(child: new Text('Screen A')),
          onPressed: () => nav.pushReplacementNamed('/ScreenA'),
        ),
        new MaterialButton(
          child: new Center(child: new Text('Screen B')),
          onPressed: () => nav.pushReplacementNamed('/ScreenB'),
        ),
        new MaterialButton(
          child: new Center(child: new Text('Screen C')),
          onPressed: () => nav.pushReplacementNamed('/ScreenC'),
        ),
      ]);
    }

    return new Scaffold(
      appBar: new AppBar(
        title: new Text('Routes test'),
      ),
      body: new Column(
        crossAxisAlignment: CrossAxisAlignment.center,
        children: children,
      ),
    );
  }
}

class ScreenA extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      body: new Center(
        child: new Text('Screen A'),
      ),
    );
  }
}

class ScreenB extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      body: new Center(
        child: new Text('Screen B'),
      ),
    );
  }
}

class ScreenC extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      body: new Center(
        child: new Text('Screen C'),
      ),
    );
  }
}

yes in ios work , in android not....

i create another project and it s working..... how can be?