dart - How to change the state of a variable from another child Widget in Flutter

Question

I have this Align Widget where I show a list item.

class _BackgroundState extends State<Background> {
  final List<Widget> list = [
    Text("1"),
    Text("2"),
    Text("3"),
  ];

  int i = 0;

 @override
 Widget build(BuildContext context){
  return Stack(
       children:[
          Align(alignment: Alignment.center, child: list[i],
          BottomMenu()
     ]);
  }

}

BottomMenu is StatelessWidget

contains multiple CustomBottomIcon Widgets that return a GestureDetector.

class _CustomBottomIconState extends State<CustomBottomIcon> {
  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: () {
        //
        setState(() {});
      },
      child: Container(
        decoration: BoxDecoration(
          color: Colors.indigo,
          borderRadius: BorderRadius.circular(100),
        ),
        height: MediaQuery.of(context).size.height / 20,
        width: MediaQuery.of(context).size.height / 20,
        child: Icon(
          widget.icon,
          color: Colors.white,
        ),
      ),
    );
  }
}

Note that the index i is not visible in the child widget. How can I change the state of i ?

Is it enough to rebuild the list item?

Answer 1

等待大神答复