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import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Code In The Video'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
// 今回はcontrollerはひとつなので、SingleTickerProviderStateMixinを使用する
class _MyHomePageState extends State<MyHomePage> with TickerProviderStateMixin {
AnimationController _controller;
Animation<double> _animation;
// initState内で_controllerと_animationの初期化を行う
@override
void initState() {
// TODO: implement initState
super.initState();
// controllerの初期化
_controller = AnimationController(
duration: Duration(seconds: 2),
vsync: this,
);
// animationの初期化
_animation = Tween(
begin: 0.0,
end: 1.0,
).animate(_controller);
}
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: Text(widget.title)),
floatingActionButton: FloatingActionButton(
// ボタン押下時にアニメーション実行
onPressed: () => _controller.forward(),
child: Text('B'),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
Container(
height: 100,
width: 100,
color: Colors.red,
),
FadeTransition(
// opacityプロパティに_animationを設定
opacity: _animation,
// Containerをフェードインさせる
child: Container(
height: 100,
width: 100,
color: Colors.blue,
),
),
Container(
height: 100,
width: 100,
color: Colors.green,
),
],
),
),
);
}
}
Also see: Tab Triggers