Прошу прощения, что с вашим кодом или недостающим ключом ничего не случилось
Вот пример, который отлично работает
void main() => runApp(new MyApp());
class MyApp extends StatefulWidget {
@override
MyAppState createState() => new MyAppState();
}
class MyAppState extends State<MyApp> {
@override
Widget build(BuildContext context) {
final title = 'Animated Container on Build';
return new MaterialApp(
title: title,
home: Scaffold(
appBar: AppBar(
title: Text(title),
),
body: Row(
children: <Widget>[
AniContainer(),
new Container(width: 10.0,),
AniContainer()
],
),
floatingActionButton: new FloatingActionButton(
onPressed: () => setState(() {}),
),
),
);
}
}
class AniContainer extends StatefulWidget {
@override
_AniContainerState createState() => _AniContainerState();
}
class _AniContainerState extends State<AniContainer> with TickerProviderStateMixin{
AnimationController _animationController2;
@override
void initState() {
super.initState();
_animationController= AnimationController(vsync: this, duration: Duration(milliseconds: 3000),value: 1)..reverse();
}
@override
void dispose() {
_animationController.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
// here are the animationController to can see the animation every tab on FloatingActionButton
_animationController= AnimationController(vsync: this, duration: Duration(milliseconds: 3000),value: 1)..reverse();
return Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
SizeTransition(
axis: Axis.vertical,
sizeFactor: _animationController,
child: Container(
height: 100,
width: 100,
color: Colors.red,
),
),
Container(
width: 100,
height: 100,
color: Colors.grey,
)
],
);
}
}