How to send parameters when navigating with Navigator.pushNamed

Question

I need to send some params to a named route. I would like to do something like:

Navigator.pushNamed('/route/1');

Or

Navigator.pushNamed('/route?param1=1');

I don't know if there is a way to do that, I am using MaterialApp with router.

Solution 1

The first way is what I use in my app.

Navigator.pushNamed('/route/1');

Don't forget to use onGenerateRoute and pass the value. Example from my app:

routes: {
        '/': (BuildContext context) => AuthPage(),
        '/products': (BuildContext context) => ProductsPage(''),
        '/admin': (BuildContext context) =>
            ProductsAdminPage(_addProduct, _deleteProduct),
      },
      onGenerateRoute: (RouteSettings settings) {
        final List<String> pathElements = settings.name.split('/');
        if (pathElements[0] != '') {
          return null;
        }
        if (pathElements[1] == 'product') {
          return MaterialPageRoute<bool>(
            builder: (BuildContext context) => ProductPage(pathElements[2]),
          );
        }
        return null;
      },
      onUnknownRoute: (RouteSettings settings) {
        return MaterialPageRoute(
            builder: (BuildContext context) => ProductsPage('Error'));
      },

Solution 2

For the direct answer to your question, see this duplicate question: How do I pass non-string data to a named route in Flutter?

However, most of the times the best way to do this is to not pass parameters between routes, but use app-state-management. For example Redux or Bloc. Where you generally modify the state while in the first screen, then navigate to the second screen and read the state. This has the advantage of being able to persist the state and reopen your app in the same state where it was closed. For more information on state management see the official docs.

Comments

[Michel Feinstein]

Possible duplicate of How do I pass non-string data to a named route in Flutter?