Flutter路径动画插件path_animation的使用
Flutter路径动画插件path_animation的使用
标题
Flutter路径动画插件path_animation的使用
内容
A Flutter package, path animation - that is used to moving the widget on given path.
获取开始
Getting started #
This will add a line like this to your package's pubspec.yaml (and run an implicit flutter pub get):
dependencies:
path_animation: ^1.1.0
使用
Usage #
```dart import 'package:path_animation/widget/path_animation.dart';PathAnimation( path: Path()…addOval(const Rect.fromLTWH(0, 0, 100, 100)), // Set the path. duration: const Duration(milliseconds: 2000), repeat: true, reverse: false, curve: Curves.decelerate, startAnimatedPercent: 0.25, drawPath: true, pathColor: Colors.red, pathWidth: 11, child: const Icon( // The Widget you want to animated to cross the path. Icons.flutter_dash, size: 30, ), ),
更多关于Flutter路径动画插件path_animation的使用的实战系列教程也可以访问 https://www.itying.com/category-92-b0.html
更多关于Flutter路径动画插件path_animation的使用的实战系列教程也可以访问 https://www.itying.com/category-92-b0.html
当然,以下是一个关于如何使用Flutter中的path_animation
插件的示例代码。这个插件允许你沿着预定义的路径进行动画处理。以下是一个简单的示例,展示如何创建一个圆形路径动画。
首先,确保你已经在pubspec.yaml
文件中添加了path_provider
和fluttertoast
依赖(如果你需要显示一些提示信息)。不过,核心依赖是path_animation
:
dependencies:
flutter:
sdk: flutter
path_provider: ^2.0.8
fluttertoast: ^8.0.8
path_animation: ^0.2.0 # 请确保使用最新版本
然后,运行flutter pub get
来安装依赖。
接下来是示例代码:
import 'package:flutter/material.dart';
import 'package:path_animation/path_animation.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(
title: Text('Path Animation Example'),
),
body: Center(
child: PathAnimationExample(),
),
),
);
}
}
class PathAnimationExample extends StatefulWidget {
@override
_PathAnimationExampleState createState() => _PathAnimationExampleState();
}
class _PathAnimationExampleState extends State<PathAnimationExample> with SingleTickerProviderStateMixin {
late AnimationController _controller;
late PathAnimation _pathAnimation;
late OffsetTween _tween;
@override
void initState() {
super.initState();
_controller = AnimationController(
duration: const Duration(seconds: 2),
vsync: this,
)..repeat(reverse: true);
// 定义一个圆形路径
final Path path = Path()
..addOval(Rect.fromLTWH(0, 0, 300, 300));
// 创建 PathMetric 和 Tangent
final PathMetric metric = path.computeMetrics().first;
final Tangent? startTangent = metric.getTangentForOffset(0.0)!;
final Tangent? endTangent = metric.getTangentForOffset(metric.length)!;
// 创建 PathAnimation 和 OffsetTween
_pathAnimation = PathAnimation(
pathMetric: metric,
orientation: PathOrientation.clockwise,
duration: _controller.duration,
);
_tween = OffsetTween(
begin: Offset.fromDirection(startTangent!.direction) * 150, // 起始点
end: Offset.fromDirection(endTangent.direction) * 150, // 结束点
)
.animate(
CurvedAnimation(
parent: _controller,
curve: Curves.easeInOut,
),
)
.chain(PathTween(path: path));
// 监听动画值变化
_tween.addListener(() {
setState(() {});
});
}
@override
void dispose() {
_controller.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
return AnimatedBuilder(
animation: _tween,
child: Container(
width: 300,
height: 300,
decoration: BoxDecoration(
border: Border.all(color: Colors.grey.shade300, width: 2),
shape: BoxShape.circle,
),
child: Center(
child: CustomPaint(
size: Size(300, 300),
painter: DotPainter(_tween.value),
),
),
),
builder: (context, child) {
return Transform.translate(
offset: _tween.value,
child: child,
);
},
);
}
}
class DotPainter extends CustomPainter {
final Offset position;
DotPainter(this.position);
@override
void paint(Canvas canvas, Size size) {
final Paint paint = Paint()
..color = Colors.red
..style = PaintingStyle.fill;
canvas.drawCircle(position, 10, paint);
}
@override
bool shouldRepaint(covariant CustomPainter oldDelegate) {
return true;
}
}
在这个示例中,我们创建了一个沿圆形路径移动的动画点。主要步骤包括:
- 创建一个
AnimationController
来控制动画的持续时间和循环。 - 定义一个圆形路径。
- 使用
PathMetric
和Tangent
来确定路径的起始和结束切线。 - 使用
PathAnimation
和OffsetTween
来创建动画。 - 使用
AnimatedBuilder
和Transform.translate
来更新动画位置。 - 使用
CustomPaint
和CustomPainter
来绘制移动的点。
这个示例展示了如何使用path_animation
插件来创建一个简单的路径动画。你可以根据需要调整路径和动画属性来实现更复杂的动画效果。