child passing data to parent and parent send something back to child. (ver 1)

child passing data to parent and parent send something back to child. (ver 1) · GitHub

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget { const MyApp({Key? key}) : super(key: key);

@override Widget build(BuildContext context) { return MaterialApp( title: 'Flutter Demo', theme: ThemeData( primarySwatch: Colors.blue, ), home: ParentWidget(), ); } }

class ParentWidget extends StatelessWidget { const ParentWidget({Key? key}) : super(key: key); final _secretValue = 'This is Top Secret Data';

void _handleRequestFromChild( {required Function onFailed, required Function(String) onSuccess, required String valueFromChild}) { if (valueFromChild == '1234') { onSuccess(_secretValue); } else { onFailed(); } }

@override Widget build(BuildContext context) { return Scaffold( appBar: AppBar( title: Text('ParentWidget'), ), body: Center( child: Column( mainAxisAlignment: MainAxisAlignment.center, children: [ TextButton( onPressed: () { Navigator.push( context, MaterialPageRoute( builder: (context) => ChildWidget(onGetSecretData: (valueFromChild) { if (valueFromChild == '1234') return _secretValue; else return '404'; }))); }, child: Text('Go to child'), ), ], ), ), ); } }

class ChildWidget extends StatelessWidget { final Function(String) onGetSecretData; const ChildWidget({Key? key, required this.onGetSecretData}) : super(key: key);

@override Widget build(BuildContext context) { return Scaffold( appBar: AppBar( title: Text('ChildWidget'), ), body: Center( child: Column( mainAxisAlignment: MainAxisAlignment.center, children: [ TextButton( onPressed: () { String valueFromParent = onGetSecretData('1234'); print(valueFromParent); }, child: Text('Get secret Data from Parent')) ], ), ), ); } }