import 'dart:math'; import 'package:flutter/material.dart'; import '../components/coordinate.dart'; /// create by 张风捷特烈 on 2020-03-19 /// contact me by email 1981462002@qq.com /// 说明: 纸 class Paper extends StatelessWidget { const Paper({super.key}); @override Widget build(BuildContext context) { return Container( color: Colors.white, child: CustomPaint( // 使用CustomPaint painter: PaperPainter(), ), ); } } class PaperPainter extends CustomPainter { final Coordinate coordinate = Coordinate(); @override void paint(Canvas canvas, Size size) { coordinate.paint(canvas, size); canvas.translate(size.width / 2, size.height / 2); Path path = Path(); Paint paint = Paint() ..color = Colors.purpleAccent ..strokeWidth = 2 ..style = PaintingStyle.stroke; var rect = Rect.fromCenter(center: Offset(0, 0), width: 160, height: 100); path.lineTo(30, 30); path..arcTo(rect, 0, pi * 1.5, true); canvas.drawPath(path, paint); path.reset(); canvas.translate(200, 0); path.lineTo(30, 30); path..arcTo(rect, 0, pi * 1.5, false); canvas.drawPath(path, paint); } @override bool shouldRepaint(CustomPainter oldDelegate) => false; }