How to kill a navigation stack? Pop all previous screens in Flutter? [duplicate]

Question

So I have this kind of walkthrough that pushes the user from one screen to another (Six screens in total). In the last page, I would like the user to press "Done" and take him back to the first screen without being able to pop back to any of the previous screens.

Right now it will pop the last screen but not any of the other ones so it take me back to my original screen with the ability to pop back to the screen before the last screen (hopefully that last sentence makes sense to you, because the last screen was popped it takes me back to the screen before that one).

Any idea how to get around that?

Thanks!

Answer 1

To pop multiple screens from the navigation stack, like in your given scenario we can use Navigator.popUntil. It takes a BuildContextand a RoutePredicate as parameters. The Navigator calls pop until the returned value by the given RoutePredicate is true.

Here is very basic example. It uses ModalRoute.withName to create the RoutePredicate:

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      routes: {
        '/': (BuildContext context) => Home(),
        '/another': (BuildContext context) => Another()
      },
    );
  }
}

class Home extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text('Home'),
            RaisedButton(
              child: Text('Take me to another screen!'),
              onPressed: () => Navigator.pushNamed(context, '/another'),
            )
          ],
        ),
      ),
    );
  }
}

class Another extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            RaisedButton(
              child: Text('Next screen.'),
              onPressed: () => Navigator.pushNamed(context, '/another'),
            ),
            RaisedButton(
              child: Text('Pop em all.'),
              onPressed: () => Navigator.popUntil(
                    context,
                    ModalRoute.withName('/'),
                  ),
            ),
          ],
        ),
      ),
    );
  }
}

Answer 2

The method you are looking for is popUntil(), take a look at the implementation https://api.flutter.dev/flutter/widgets/Navigator/popUntil.html or https://api.flutter.dev/flutter/widgets/NavigatorState/popUntil.html

You will have to do probably something like

Navigator.of(context).popUntil(ModalRoute.withName('/my-target-screen'));

(take a look at https://api.flutter.dev/flutter/widgets/ModalRoute/withName.html)

or use some custom function (https://api.flutter.dev/flutter/widgets/RoutePredicate.html).