Flutter：如何使用 CustomPaint 绘制心形

在Flutter中，要使用CustomPaint来绘制一个心形图案，你需要定义一个CustomPainter类，并在该类中实现paint方法来绘制图案。以下是一个简单的例子：

import 'package:flutter/material.dart';
 
void main() => runApp(MyApp());
 
class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: Center(
          child: CustomPaint(
            size: Size(200, 200),
            painter: HeartPainter(),
          ),
        ),
      ),
    );
  }
}
 
class HeartPainter extends CustomPainter {
  @override
  void paint(Canvas canvas, Size size) {
    final paint = Paint()
      ..color = Colors.red
      ..style = PaintingStyle.fill;
 
    final offset = Offset(size.width / 2, size.height / 2);
    final scale = min(size.width, size.height) / 200;
 
    canvas.translate(offset.dx, offset.dy);
    canvas.scale(scale);
 
    // 心形路径定义
    Path path = Path()
      ..moveTo(85.873, 33.087)
      ..cubicTo(
48.503, 15.313, 29.893, 10.75, 38.613, 10.75)
      ..cubicTo(57.313, 10.75, 70.107, 22.479, 70.107, 34.113)
      ..cubicTo(70.107, 45.747, 57.313, 57.938, 43.827, 57.938)
      ..cubicTo(30.343, 57.938, 17.687, 45.747, 17.687, 34.113)
      ..cubicTo(17.687, 22.479, 30.343, 10.75, 43.827, 10.75)
      ..cubicTo(57.313, 10.75, 69.688, 22.479, 69.688, 34.113)
      ..cubicTo(69.688, 45.747, 57.313, 57.938, 43.827, 57.938)
      ..cubicTo(30.343, 57.938, 17.687, 45.747, 17.687, 34.113)
      ..cubicTo(17.687, 27.52, 30.343, 14.563, 43.827, 14.563)
      ..cubicTo(57.313, 14.563, 69.688, 27.52, 69.688, 34.113)
      ..cubicTo(69.688, 35.747, 57.313, 44.938, 43.827, 44.938)
      ..cubicTo(30.343, 44.938, 17.687, 35.747, 17.687, 34.113)
      ..cubicTo(17.687, 22.479,