ValueListenableBuilder

Like set state, it changes a widget every time a variable is updated

First, we will declare a variable of type ValueNotifier which is a special type of class.

ValueNotifier<int> _counter = ValueNotifier<int>(0);

Now in the next step let’s see the widget code.

ValueListenableBuilder(
    valueListenable: _counter,
    builder: (context, value, child) {
       return Text('$value', style: Theme.of(context).textTheme.headline4,);
    },
)

To update the variable, you can do:

_varIndex.value++;