No TabController for TabBar - flutter

Question

I'm trying to add a tabBar to my app, but I'm having some issues getting it to build. I've followed the documentation and added a tabController, but I'm getting an error saying I don't have one. My code is below.
class _MyAppState extends State<MyApp> with TickerProviderStateMixin {
TabController _controller;
final List<Tab> topTabs = <Tab>[
new Tab(text: 'Profile'),
new Tab(text: 'Match'),
new Tab(text: 'Chat'),
];
#override
void initState() {
super.initState();
_controller = TabController(vsync: this, length: 3);
}
#override
void dispose() {
_controller.dispose();
super.dispose();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('MyApp'),
bottom: TabBar(
controller: _controller,
tabs: topTabs,
),
),
body: TabBarView(
controller: _controller,
children: [
new Container(
color: Colors.lightBlueAccent,
child: Center(child: Text('Profile', style: TextStyle(color: Colors.white),),),
),
new Container(
color: Colors.purpleAccent,
child: Center(child: Text('Match', style: TextStyle(color: Colors.white),),),
),
new Container(
color: Colors.lightGreenAccent,
child: Center(child: Text('Chat', style: TextStyle(color: Colors.white),),),
)
]),
);
}
}
The exact error is flutter: ══╡ EXCEPTION CAUGHT BY WIDGETS LIBRARY ╞═══════════════════════════════════════════════════════════
flutter: The following assertion was thrown building MediaQuery(MediaQueryData(size: Size(375.0, 667.0),
flutter: devicePixelRatio: 2.0, textScaleFactor: 1.0, platformBrightness: Brightness.light, padding:
flutter: EdgeInsets.zero, viewPadding: EdgeInsets.zero, viewInsets: EdgeInsets.zero, physicalDepth:
flutter: 1.7976931348623157e+308, alwaysUse24HourFormat: false, accessibleNavigation: false, highContrast:
flutter: false, disableAnimations: false, invertColors: false, boldText: false)):
flutter: No TabController for TabBar.
flutter: When creating a TabBar, you must either provide an explicit TabController using the "controller"
flutter: property, or you must ensure that there is a DefaultTabController above the TabBar.
flutter: In this case, there was neither an explicit controller nor a default controller.

Answer 1

I could run it without a problem, did you overwrote MyApp example when creating your project that has the MaterialApp with your code or something before the main?
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
home: MyAppState()
);
}
}
class MyAppState extends StatefulWidget{
#override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyAppState> with TickerProviderStateMixin {
TabController _controller;
final List<Tab> topTabs = <Tab>[
new Tab(text: 'Profile'),
new Tab(text: 'Match'),
new Tab(text: 'Chat'),
];
#override
void initState() {
super.initState();
_controller = TabController(vsync: this, length: 3);
}
#override
void dispose() {
_controller.dispose();
super.dispose();
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('MyApp'),
bottom: TabBar(
controller: _controller,
tabs: topTabs,
),
),
body: TabBarView(
controller: _controller,
children: [
new Container(
color: Colors.lightBlueAccent,
child: Center(child: Text('Profile', style: TextStyle(color: Colors.white),),),
),
new Container(
color: Colors.purpleAccent,
child: Center(child: Text('Match', style: TextStyle(color: Colors.white),),),
),
new Container(
color: Colors.lightGreenAccent,
child: Center(child: Text('Chat', style: TextStyle(color: Colors.white),),),
)
]),
);
}
}