具有自定义形状的颤振按钮-（三角形）

Question

我已经创建了一个圆形按钮，在这种情况下RawMaterialButton，我正尝试使用CustomPaint它在其中心创建一个三角形，但这ShapesPainter并不是为ClearButton'. I tried other buttons but couldn't get any of them to acceptShapesPainter 类定义的。

RawMaterialButton(
          child: CustomPaint(
            painter: ShapesPainter(),
            child: Container(
              height: 40,
            ),
          ),
          onPressed: onPressed,
          constraints: BoxConstraints.tightFor(
            width: 90.0,
            height: 90.0,
          ),
          shape: RoundedRectangleBorder(),
          fillColor: Colors.transparent,
        )

应该使用哪种按钮类型？ShapesPainter或者如何创建一个中心为三角形或其他形状的圆形按钮？

这是我尝试创建的按钮，如您所见，它基本上是一个带有三角形的圆形按钮。

Answer 1

创建自定义剪辑器

class CustomTriangleClipper extends CustomClipper<Path> {
  @override
  Path getClip(Size size) {
    final path = Path();
    path.lineTo(size.width, 0);
    path.lineTo(size.width, size.height);
    path.lineTo(0, 0);
    return path;
  }

  @override
  bool shouldReclip(CustomClipper<Path> oldClipper) {
    return false;
  }
}

然后用法：

ClipPath(
    clipper: CustomTriangleClipper(),
    child: Container(
      width: 50,
      height: 50,
      decoration: BoxDecoration(
        gradient: LinearGradient(
          begin: Alignment.bottomLeft,
          end: Alignment.topRight,
          colors: [Color(0xffF25D50), Color(0xffF2BB77)],
        ),
      ),
    ),
  );

Answer 2

您可以通过创建自己的自定义绘画工具实现来实现。

三角画家

class TrianglePainter extends CustomPainter {
  final Color strokeColor;
  final PaintingStyle paintingStyle;
  final double strokeWidth;

  TrianglePainter({this.strokeColor = Colors.black, this.strokeWidth = 3, this.paintingStyle = PaintingStyle.stroke});

  @override
  void paint(Canvas canvas, Size size) {
    Paint paint = Paint()
      ..color = strokeColor
      ..strokeWidth = strokeWidth
      ..style = paintingStyle;

    canvas.drawPath(getTrianglePath(size.width, size.height), paint);
  }

  Path getTrianglePath(double x, double y) {
    return Path()
      ..moveTo(0, y)
      ..lineTo(x / 2, 0)
      ..lineTo(x, y)
      ..lineTo(0, y);
  }

  @override
  bool shouldRepaint(TrianglePainter oldDelegate) {
    return oldDelegate.strokeColor != strokeColor ||
        oldDelegate.paintingStyle != paintingStyle ||
        oldDelegate.strokeWidth != strokeWidth;
  }
}

用法

class HomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: RawMaterialButton(
          onPressed: () {},
          child: CustomPaint(
            painter: TrianglePainter(
              strokeColor: Colors.blue,
              strokeWidth: 10,
              paintingStyle: PaintingStyle.fill,
            ),
            child: Container(
              height: 180,
              width: 200,
            ),
          ),
        ),
      ),
    );
  }
}