call method in one stateful widget from another stateful widget - Flutter

Question

I have a flutter project that i am working on i cant put the whole code cause its more than 500 lines of code so i will try to ask my question as simply as i acn using the i

Answer 1

Here HomePage is parent page and ChildPage is child page. There is one method called onSelectItem, which we need to call from child page.

class HomePage extends StatefulWidget {

  @override HomePageState createState() => HomePageState();
}

class HomePageState extends State {

  onSelectItem(String param) {
    print(param);
  }

  @override Widget build(BuildContext context) {

  }
}

class ChildPage extends StatefulWidget {
  final HomePageState homePageState;

  ChildPage({Key key, @required this.homePageState}) : super(key: key);

  _ChildPageState createState() => _ChildPageState();
}

class _ChildPageState extends State {
  @override Widget build(BuildContext context) {

    return RaisedButton(
      onPressed: () {
        widget.homePageState.onSelectItem("test");
      },
      child: const Text(
          'Click here',
          style: TextStyle(fontSize: 20)
      ),
    );
  }
}

So, by using the widget and parent class state we can call the parent class method.