How to pass a list from second screen to first screen in flutter?-CodePudding

I have a stateful widget in my first and second screen. I have a list in my second screen and want to pass it to my first screen.

How to do it ?

I know how to pass a single data between screens but it didn't work for a list.

CodePudding user response：

Navigator.push( is a future method, you can wait until it pop.

On First page

final result = await Navigator.push(
    context,
    MaterialPageRoute(
      builder: (context) => const SecondScreen(),
    ));
  data = result;
setState(() {});

And on second page while pop.

final data = List.generate(33, (index) => index);
Navigator.of(context).pop(data);

Example snippet

void main() => runApp(
      MaterialApp(
        debugShowCheckedModeBanner: false,
        title: 'Flutter Demo',
        theme: ThemeData(
          primarySwatch: Colors.blue,
        ),
        home: FirstScreen(),
      ),
    );

class FirstScreen extends StatefulWidget {
  const FirstScreen({super.key});

  @override
  State<FirstScreen> createState() => _FirstScreenState();
}

class _FirstScreenState extends State<FirstScreen> {
  List<int> data = [];
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: ListView.builder(
        itemCount: data.length,
        itemBuilder: (context, index) {
          return ListTile(
            title: Text(data[index].toString()),
          );
        },
      ),
      floatingActionButton: FloatingActionButton(onPressed: () async {
        final result = await Navigator.push(
            context,
            MaterialPageRoute(
              builder: (context) => const SecondScreen(),
            ));
        data = result;
        setState(() {});
      }),
    );
  }
}

class SecondScreen extends StatelessWidget {
  const SecondScreen({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: ElevatedButton(
          onPressed: () {
            final data = List.generate(33, (index) => index);
            Navigator.of(context).pop(data);
          },
          child: Text("pop")),
    );
  }
}

CodePudding user response：

In first screen to navigate to second:

final response await Navigator.push(context, MaterialPageRoute(builder: (context) => const SecondScreen()));

if (response is myObjectOrList) {
   //use it
}

In second screen

Navigator.pop(context, myObjectOrList);