Riverpod

 

1.

void main() {

  runApp(
    // For widgets to be able to read providers, we need to wrap the entire
    // application in a "ProviderScope" widget.
    // This is where the state of our providers will be stored.
       ProviderScope( //<--- required this 👈👈👈👈
      child: NewProvider(),
    ),
  );
}

2. 

import 'package:flutter/cupertino.dart';

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

// globle get method data 👇👇👇👇👇
final helloWorldProvider3 = Provider((_) => 'Hello world16 ');

// globle set method 👇👇👇👇👇
final counterStateProvider = StateProvider<int>((ref) {
  return 0;
});

class NewProvider extends ConsumerWidget {


  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final String value = ref.watch(helloWorldProvider3);
    final int value2 = ref.watch(counterStateProvider);

    return  MaterialApp(
      home: Scaffold(
        appBar: AppBar(title:  Text("$value2")),
        body: Center(
          child: GestureDetector(
            onTap: () {
              ref.read(counterStateProvider.notifier).state++;
            },
              child: Text(value)),
        ),
      ),
    );
  }
}