Im trying to draw the ticket model using dart canvas.

But I just can't draw those semi-circles. path.arcToPoint seems not to work.

CodePudding user response：

Try this demo:

import 'package:flutter/material.dart';

class Ticket extends CustomPainter {

  @override
  void paint(Canvas canvas, Size size) {
    final paint = Paint()
      ..color = Colors.orange
      ..strokeWidth = 2
      ..style = PaintingStyle.stroke
      ..strokeCap = StrokeCap.round;
    Path path = Path();
    //top
    path.moveTo(50, 0);
    path.lineTo(50, 150);
    path.arcToPoint(const Offset(70, 170), radius: const Radius.circular(20));
    path.lineTo(300, 170);
    path.arcToPoint(const Offset(320, 150), radius: const Radius.circular(20));
    path.lineTo(320, 0);

    //bottom
    path.moveTo(70, 170);
    path.lineTo(300, 190);
    path.arcToPoint(const Offset(320, 210), radius: const Radius.circular(20), clockwise: false);
    path.lineTo(310, 290);
    path.arcToPoint(const Offset(290, 300), radius: const Radius.circular(20));
    path.lineTo(60, 280);
    path.arcToPoint(const Offset(40, 260), radius: const Radius.circular(20));
    path.lineTo(50, 190);
    path.arcToPoint(const Offset(70, 170), radius: const Radius.circular(20), clockwise: false);
    canvas.drawPath(path, paint);
  }

  @override
  bool shouldRepaint(Ticket oldDelegate) => false;

  @override
  bool shouldRebuildSemantics(Ticket oldDelegate) => false;
}

use:

@override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.white,
      body: Center(
        child: CustomPaint(
          painter: Ticket(),
          child: SizedBox(
            width: MediaQuery.of(context).size.width,
            height: MediaQuery.of(context).size.height,
          ),
        ),
      ),
    );
  }