一统天下 flutter https://github.com/webabcd/flutter_demo
作者 webabcd
一统天下 flutter - 动画: Tween - 补间动画(曲线型动画)
示例如下:
lib\animation\tween2.dart
/*
* Tween - 补间动画(曲线型动画)
*
* CurvedAnimation 继承自 Animation<double>,其可以支持曲线型动画(缓动动画)
*/
import 'package:flutter/material.dart';
import 'package:flutter_demo/helper.dart';
class Tween2Demo extends StatefulWidget {
const Tween2Demo({Key? key}) : super(key: key);
@override
_Tween2DemoState createState() => _Tween2DemoState();
}
class _Tween2DemoState extends State<Tween2Demo> with SingleTickerProviderStateMixin {
late Animation<double> _animation;
late AnimationController _controller;
@override
void initState() {
super.initState();
_controller = AnimationController(vsync: this, duration: const Duration(seconds: 3),);
/// 实例化 CurvedAnimation(曲线型动画)
/// parent - 关联的 Animation<double> 对象,这个 Animation<double> 的 double 的范围必须在 0.0 到 1.0 之间
/// curve - 缓动类型
CurvedAnimation curvedAnimation = CurvedAnimation(parent: _controller, curve: Curves.bounceInOut);
/// 通过 Tween<T> 的构造函数指定需要做补间动画的类型为 double 类型,范围是 100 到 300 之间
/// 通过 animate() 将指定的 Animation<double> 对象(0.0 - 1.0 之间)转换为需要的 Animation<double> 对象(100.0 - 300.0 之间)
_animation = Tween<double>(begin: 100, end: 300).animate(curvedAnimation)
..addListener(() {
log("value: ${_animation.value}");
setState(() {
});
});
/// 注:tween.animate(animation) 和 animation.drive(tween) 是一样,比如下面两句的结果是一样的
// _animation = Tween<double>(begin: 100, end: 300).animate(curvedAnimation);
// _animation = curvedAnimation.drive(Tween<double>(begin: 100, end: 300));
}
@override
Widget build(BuildContext context) {
return Container(
color: Colors.orange,
child: Column(
children: [
Flexible(
child: Center(
child: Container(
color: Colors.blue,
height: _animation.value,
width: _animation.value,
),
),
),
Container(
height: 40,
color: Colors.red,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
ElevatedButton(
child: const Text('repeat'),
onPressed: () {
_controller.repeat(reverse: true);
},
),
],
),
),
],
),
);
}
@override
void dispose() {
/// 清理 AnimationController
_controller.dispose();
super.dispose();
}
}
标签:动画,Tween,animation,补间,Animation,flutter From: https://www.cnblogs.com/webabcd/p/flutter_lib_animation_tween2.html一统天下 flutter https://github.com/webabcd/flutter_demo
作者 webabcd