gistfile1.txt

import 'package:flutter/material.dart';

class HomePage extends StatefulWidget {
  @override
  _HomePageState createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> with TickerProviderStateMixin {
  TabController _tabController;
  final GlobalKey<State> _item0Key = new GlobalKey<State>(debugLabel: 'item0Key');

  @override
  void initState() {
    super.initState();
    _tabController = new TabController(length: 3, vsync: this);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        child: Column(
          children: <Widget>[
            TabBar(
              controller: _tabController,
              labelColor: Colors.blue,
              tabs: [
                Tab(text: "Tab0"),
                Tab(text: "Tab1"),
                Tab(text: "Tab2"),
              ],
            ),
            Expanded(
              child: TabBarView(
                controller: _tabController,
                children: <Widget>[
                  Center(key: _item0Key, child: Text('Tab0')),
                  Center(child: Text('Tab1')),
                  Center(child: Text('Tab2')),
                ],
              ),
            )
          ],
        ),
      ),
    );
  }
}

void main() {
  runApp(MaterialApp(home: HomePage()));
}