To be able to access providers accross navigations, you need to provide it before MaterialApp as follows
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return ChangeNotifierProvider(
create: (_) => ViewModel(),
child: MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(),
),
);
}
}
class MyHomePage extends StatelessWidget {
const MyHomePage({Key key}) : super(key: key);
@override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: RaisedButton(
child: Text("DetailView"),
onPressed: () => Navigator.of(context).push(
MaterialPageRoute(
builder: (context) => DetailScreen(),
),
),
)));
}
}
class DetailScreen extends StatelessWidget {
const DetailScreen({Key key}) : super(key: key);
@override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: RaisedButton(
child: Text("EditScreen"),
onPressed: () => Navigator.of(context)
.push(MaterialPageRoute(builder: (context) => EditScreen())),
),
));
}
}
class EditScreen extends StatelessWidget {
const EditScreen({Key key}) : super(key: key);
@override
Widget build(BuildContext context) {
return Scaffold(
body: Center(
child: RaisedButton(
child: Text("Print"),
onPressed: () =>
Provider.of<ViewModel>(context, listen: false).printNumber()),
),
);
}
}
class ViewModel extends ChangeNotifier {
printNumber() {
print(2);
}
}