如何在Flutter中创建一个分成4个部分的圆？

class FourPartCirclePainter extends CustomPainter {
  @override
  void paint(Canvas canvas, Size size) {
    double radius = size.width / 2;
    double centerX = size.width / 2;
    double centerY = size.height / 2;

    // 绘制第一个部分
    canvas.drawArc(
      Rect.fromCircle(center: Offset(centerX, centerY), radius: radius),
      0,
      pi / 2,
      true,
      Paint()..color = Colors.blue,
    );

    // 绘制第二个部分
    canvas.drawArc(
      Rect.fromCircle(center: Offset(centerX, centerY), radius: radius),
      pi / 2,
      pi / 2,
      true,
      Paint()..color = Colors.green,
    );

    // 绘制第三个部分
    canvas.drawArc(
      Rect.fromCircle(center: Offset(centerX, centerY), radius: radius),
      pi,
      pi / 2,
      true,
      Paint()..color = Colors.yellow,
    );

    // 绘制第四个部分
    canvas.drawArc(
      Rect.fromCircle(center: Offset(centerX, centerY), radius: radius),
      3 * pi / 2,
      pi / 2,
      true,
      Paint()..color = Colors.red,
    );
  }

  @override
  bool shouldRepaint(CustomPainter oldDelegate) {
    return false;
  }
}

class FourPartCirclePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Four Part Circle'),
      ),
      body: Center(
        child: CustomPaint(
          painter: FourPartCirclePainter(),
          size: Size(200, 200),
        ),
      ),
    );
  }
}