直接上源代码,直观可运行
import 'package:flutter/material.dart';
class FadeTransitionDemo extends StatefulWidget {
const FadeTransitionDemo({Key? key}) : super(key: key);
@override
_FadeTransitionDemoState createState() => _FadeTransitionDemoState();
}
class _FadeTransitionDemoState extends State<FadeTransitionDemo>
with SingleTickerProviderStateMixin {
late final AnimationController _controller = AnimationController(
duration: const Duration(seconds: 2),
vsync: this,
)..repeat(reverse: true);
late final Animation<double> _animation = CurvedAnimation(
parent: _controller,
curve: Curves.easeIn,
);
@override
void dispose() {
_controller.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
return Container(
color: Colors.white,
child: FadeTransition(
opacity: _animation,
child: const Padding(padding: EdgeInsets.all(8), child: FlutterLogo()),
),
);
}
}