samples/cupertino_gallery/lib/widgets/picker_page.dart

import 'package:flutter/cupertino.dart';

class PickerPage extends StatelessWidget {
  const PickerPage({super.key});

  @override
  Widget build(BuildContext context) {
    return CupertinoPageScaffold(
      navigationBar: const CupertinoNavigationBar(middle: Text('Picker')),
      child: Center(
        child: SizedBox(
          height: 200,
          child: CupertinoPicker(
            itemExtent: 32,
            onSelectedItemChanged: (index) {},
            children: const <Widget>[Text('One'), Text('Two'), Text('Three')],
          ),
        ),
      ),
    );
  }
}