tab_bar_demo_with_keep_alive.dart

import 'package:flutter/material.dart';

class TabBarDemo extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: DefaultTabController(
        length: 2,
        child: Scaffold(
          appBar: AppBar(
            title: const Text('TabBar Demo'),
            bottom: const TabBar(tabs: [Tab(text: 'Tab Item'), Tab(text: 'Tab Item')]),
          ),
          body: TabBarView(
            children: [
              TabBarViewItem(),
              TabBarViewItem(),
            ],
          ),
        ),
      ),
    );
  }
}

class TabBarViewItem extends StatefulWidget {
  @override
  _TabBarViewItemState createState() => _TabBarViewItemState();
}

class _TabBarViewItemState extends State<TabBarViewItem> with AutomaticKeepAliveClientMixin {
  @override
  Widget build(BuildContext context) {
    super.build(context);
    return const Center(child: Text('Tab Bar View Item Content'));
  }

  @override
  bool get wantKeepAlive => true;
}