81 lines
1.7 KiB
Dart
81 lines
1.7 KiB
Dart
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import 'dart:ui';
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import 'package:flutter/material.dart';
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import '../components/coordinate.dart';
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/// create by 张风捷特烈 on 2020/5/1
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/// contact me by email 1981462002@qq.com
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/// 说明:
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class Paper extends StatelessWidget {
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const Paper({super.key});
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@override
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Widget build(BuildContext context) {
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return Container(
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color: Colors.white,
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child: CustomPaint(
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// 使用CustomPaint
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painter: PaperPainter(),
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),
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);
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}
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}
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class PaperPainter extends CustomPainter {
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final Coordinate coordinate=Coordinate();
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final Offset p1 = Offset(80, -100);
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final Offset p2 = Offset(160, 0);
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@override
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void paint(Canvas canvas, Size size) {
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coordinate.paint(canvas, size);
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canvas.translate(size.width / 2, size.height / 2);
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Path path = Path();
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Paint paint = Paint()
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..color = Colors.purpleAccent
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..strokeWidth = 2
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..style = PaintingStyle.stroke;
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//抛物线
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path.conicTo(p1.dx, p1.dy, p2.dx, p2.dy, 1);
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_drawHelper(canvas);
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canvas.drawPath(path, paint);
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//椭圆线
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path.reset();
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canvas.translate(-180, 0);
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path.conicTo(p1.dx, p1.dy, p2.dx, p2.dy, 0.5);
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canvas.drawPath(path, paint);
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_drawHelper(canvas);
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//双曲线
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path.reset();
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canvas.translate(180+180.0, 0);
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path.conicTo(p1.dx, p1.dy, p2.dx, p2.dy, 1.5);
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canvas.drawPath(path, paint);
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_drawHelper(canvas);
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}
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void _drawHelper(Canvas canvas) {
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canvas.drawPoints(
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PointMode.points,
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[
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p1,
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p2,
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],
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Paint()
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..strokeWidth = 6
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..strokeCap = StrokeCap.round
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..color = Colors.blue);
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}
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@override
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bool shouldRepaint(CustomPainter oldDelegate) => false;
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}
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