import 'package:flutter/material.dart'; Widget buildPicker(List items, Function(int idx) onSelected) { return SizedBox( height: 111, child: Stack( children: [ Positioned( top: 36, bottom: 36, left: 0, right: 0, child: Container( height: 37, decoration: const BoxDecoration( borderRadius: BorderRadius.all(Radius.circular(7)), color: Colors.black12, ), ), ), ListWheelScrollView.useDelegate( itemExtent: 37, diameterRatio: 1.2, controller: FixedExtentScrollController(initialItem: 0), onSelectedItemChanged: (idx) => onSelected(idx), physics: const FixedExtentScrollPhysics(), childDelegate: ListWheelChildBuilderDelegate( builder: (context, index) => Center( child: items[index], ), childCount: items.length, ), ) ], ), ); }