Flutter Animation实现缩放和滑动动画效果
时间：2022-09-29 11:05:32|栏目：Android代码|点击： 次
本文实例为大家分享了Flutter Animation实现缩放和滑动动画的具体代码，供大家参考，具体内容如下
Animation对象是Flutter动画库中的一个核心类，它生成指导动画的值。
Animation对象知道动画的当前状态（例如，它是开始、停止还是向前或向后移动），但它不知道屏幕上显示的内容。
AnimationController管理Animation。
CurvedAnimation 将过程抽象为一个非线性曲线.
Tween在正在执行动画的对象所使用的数据范围之间生成值。例如，Tween可能会生成从红到蓝之间的色值，或者从0到255。
使用Listeners和StatusListeners监听动画状态改变。
import 'package:flutter/animation.dart';
import 'package:flutter/material.dart';
void main() {
runApp(new LogoApp());
}
class LogoApp extends StatefulWidget {
_LogoAppState createState() => new _LogoAppState();
}
class _LogoAppState extends State<LogoApp> with SingleTickerProviderStateMixin {
AnimationController controller;
Animation<double> animation;
initState() {
super.initState();
controller = new AnimationController(
duration: const Duration(milliseconds: 10000), vsync: this);
animation = new Tween(begin: 0.0, end: 300.0).animate(controller);
controller.forward();
}
Widget build(BuildContext context) {
return new AnimatedLogo(animation: animation);
}
dispose() {
controller.dispose();
super.dispose();
}
}
class AnimatedLogo extends AnimatedWidget {
AnimatedLogo({Key key, Animation<double> animation})
: super(key: key, listenable: animation);
Widget build(BuildContext context) {
final Animation<double> animation = listenable;
return new Center(
child: new Container(
margin: new EdgeInsets.symmetric(vertical: 10.0),
height: animation.value,
width: animation.value,
child: new FlutterLogo(),
),
);
}
}
缩放功能
class ScaleAnimatedContent extends StatefulWidget {
final Widget child;
final bool show;
const ScaleAnimatedContent({Key key, this.child, this.show = false})
: super(key: key);
@override
ScaleAnimatedContentState createState() => ScaleAnimatedContentState();
}
class ScaleAnimatedContentState extends State<ScaleAnimatedContent>
with TickerProviderStateMixin {
AnimationController animationController;
Animation<double> animation;
@override
void initState() {
animationController = new AnimationController(
vsync: this,
duration: new Duration(milliseconds: 600),
);
// animationSlideUp = new Tween(begin: 0.0,end: 1.0).animate(animationController);
animation = Tween(begin: 0.0, end: 1.0).animate(animationController);
if (widget.show) {
animationController.forward();
}
super.initState();
}
@override
void didUpdateWidget(ScaleAnimatedContent oldWidget) {
if (widget != oldWidget) {
if (widget.show && !oldWidget.show) {
animationController.forward(from: 0.0);
} else if (!widget.show) {
animationController.reverse();
}
}
super.didUpdateWidget(oldWidget);
}
@override
Widget build(BuildContext context) {
return ScaleTransition(
scale: animation,
child: widget.child,
);
}
@override
void dispose() {
animationController.dispose();
super.dispose();
}
}
滑动效果
class SlideAnimatedContent extends StatefulWidget {
final Widget child;
final bool show;
const SlideAnimatedContent({Key key, this.child, this.show = false})
: super(key: key);
@override
SlideAnimatedContentState createState() => SlideAnimatedContentState();
}
class SlideAnimatedContentState extends State<SlideAnimatedContent>
with TickerProviderStateMixin {
AnimationController animationController;
Animation<Offset> animationSlideUp;
@override
void initState() {
animationController = new AnimationController(
vsync: this,
duration: new Duration(milliseconds: 600),
);
animationSlideUp = new Tween(
begin: Offset(0.0, 5.0),
end: Offset(0.0, 0.0),
).animate(CurvedAnimation(parent: animationController, curve: Curves.ease));
if (widget.show) {
animationController.forward();
}
super.initState();
}
@override
void didUpdateWidget(SlideAnimatedContent oldWidget) {
if (widget != oldWidget) {
if (widget.show && !oldWidget.show) {
animationController.forward(from: 0.0);
} else if (!widget.show) {
animationController.reverse();
}
}
super.didUpdateWidget(oldWidget);
}
@override
Widget build(BuildContext context) {
return SlideTransition(
position: animationSlideUp,
child: FadeTransition(
opacity: animationController,
child: widget.child,
),
);
}
@override
void dispose() {
animationController.dispose();
super.dispose();
}
}
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本文标题：Flutter Animation实现缩放和滑动动画效果
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