how to add multiple ChangeNotifierProvider in same type in Flutter

Question

Is it possible to add same type multiple ChangeNotifierProvider?

return MultiProvider(
  providers: [
      ChangeNotifierProvider<ValueNotifier<double>>(
        create: (_) => ValueNotifier<double>(0.0),
      ),
      ChangeNotifierProvider<ValueNotifier<double>>(
        create: (_) => ValueNotifier<double>(0.0),
      ),
  ],

In my build method

 @override
  Widget build(BuildContext context) {
    ValueNotifier<double> firstNotifier = Provider.of(context, listen: true);
    ValueNotifier<double> secondNotifier = Provider.of(context, listen: true);

  print('First value ${firstNotifier.value} Second value ${secondNotifier.value}');

 ...
 onTap:(){
   firstNotifier.value = 10.0;
   secondNotifier.value = 30.0;
 }

both printed values are same First value is 10 Second value is 10

Answer 1

There is an elegant way to do it, but we will have to create two separate class which extend changeNotifierProvider

class FirstNotifier with ChangeNotifier{
  double value=0; //default
  void ChangeValue(double newValue){
    value=newValue
    notifyListeners();
  }
}

And second notifier as ;

class SecondNotifier with ChangeNotifier{
  double value=0; //default
  void ChangeValue(double newValue){
    value=newValue
    notifyListeners();
  }
}

Then in inside your build method you can access them as

final firstNotifier = Provider.of<FirstNotifier>(context, listen:true)
final secondNotifier = Provider.of<SecondNotifier>(context, listen:true)

Then you can make changes in them as

firstNotifier.ChangeValue(30); 

In the MultiProvider Code, then you can wrap Providers as

return MultiProvider(
  providers: [
      ChangeNotifierProvider<FirstNotifier>(
        create: (_) => FirstNotifier,
      ),
      ChangeNotifierProvider<SecondNotifier >(
        create: (_) => SecondNotifier ,
      ),
  ],

That will do the trick