import 'dart:ui'; import 'package:flutter/material.dart'; import '../components/coordinate_pro.dart'; /// create by 张风捷特烈 on 2020/5/1 /// contact me by email 1981462002@qq.com /// 说明: 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(); Offset p1 = Offset(100, 100); Offset p2 = Offset(120, -60); Paint _helpPaint = Paint(); @override void paint(Canvas canvas, Size size) { coordinate.paint(canvas, size); canvas.translate(size.width / 2, size.height / 2); Paint paint = Paint() ..color = Colors.orange ..style = PaintingStyle.stroke ..strokeWidth = 2; Path path = Path(); path.quadraticBezierTo(p1.dx, p1.dy, p2.dx, p2.dy); canvas.drawPath(path, paint); _drawHelp(canvas); } void _drawHelp(Canvas canvas) { _helpPaint ..color = Colors.purple ..style = PaintingStyle.stroke ..strokeCap = StrokeCap.round; canvas.drawPoints(PointMode.lines,[Offset.zero, p1, p1,p2], _helpPaint..strokeWidth=1); canvas.drawPoints(PointMode.points, [Offset.zero, p1, p1, p2], _helpPaint..strokeWidth = 8); } @override bool shouldRepaint(CustomPainter oldDelegate) => false; }