Flutter: Move to a new screen without providing navigate back to previous screen

Question

I'm implementing an authentication flow in my Flutter app.

After a sign in attempt, the CheckAuth (which checks whether a user is signed in or not and then opens home screen or sign up screen accordingly) is opened with this code:

  void _signIn() async {
    await _auth
        .signInWithEmailAndPassword(
            email: _userEmail.trim(), password: _userPassword.trim())
        .then((task) {
      // go to home screen
      if (task.getIdToken() != null) {
        setState(() {
          Navigator.pushReplacement(
              context,
              new MaterialPageRoute(
                  builder: (BuildContext context) => new CheckAuth()));
        });
      } else {
        print("Authentication failed");
      }
    });
  }

Problem: I can successfully sign in to the app, but if I tap back button after I sign in, it goes back to the sign in screen (while I expect it to exit from the app).

Question: How to move from one screen to another in Flutter without the way back?

Do I need to somehow delete the navigator history? Or don't use navigator at all? I tried Navigator.replace method, but it didn't seem to work.

Answer 1

You need to use Navigator.pushReplacement when leaving the auth screen too. Not just when redirecting to login page.

Answer 2

You can use the pushAndRemoveUntil method:

Push the given route onto the navigator that most tightly encloses the given context, and then remove all the previous routes until the predicate returns true. To remove all the routes below the pushed route, use a [RoutePredicate] that always returns false (e.g. (Route<dynamic> route) => false).

Navigator.pushAndRemoveUntil(
  context,
  MaterialPageRoute(builder: (context) => MainPage()),
  (Route<dynamic> route) => false,
);

Answer 3

You need to use

Navigator
    .of(_context)
    .pushReplacement(new MaterialPageRoute(builder: (BuildContext context) => page));

Where _context is object of BuildContext And page is which page you directed to.

Answer 4

We can use routes for the same Like:

routes: {

        LoginScreen.route_name: (_) => LoginScreen(),
        .....
      },  

And use below code whenever you want to push and remove the backstack

Navigator.of(context).pushReplacementNamed(LoginScreen.route_name);

Note: Define static String inside widget LoginScreen

Answer 5

Here is the solution -

Use pushAndRemoveUntil instead of pushReplacement

Also, can be use maintainState: true

For set root page

Navigator.pushAndRemoveUntil(
  context,
  MaterialPageRoute(
      builder: (context) => pageName, maintainState: true),
      (Route<dynamic> route) => false);

For Push Page one page to another

Navigator.push(
context,
MaterialPageRoute(
    builder: (context) => pageName,
    maintainState: false),)

**If you want to refresh always while appearing page then use: **

maintainState: false

Answer 6

I think you probably have already solved this. But you can set "automaticallyLeadingImplied: false" in the AppBar of the Scaffold you are navigating to.

Answer 7

I have resolved this by popping from current page and showing new page:

Navigator.pop(context);
Navigator.of(context).pushReplacement(MaterialPageRoute(builder: (context) => newPage));

Answer 8

Just simply add the below code:

Navigator.of(context).pushNamedAndRemoveUntil('/routeName', (route) => false);

Answer 9

For anyone wondering there is a new argument that needs to be returned false Navigator.of(context).pushNamedAndRemoveUntil('/', (route) => false);