如何在 flutter 中创建具有圆边的自定义容器？

Question

I am trying to create a custom container with round edges but not able to make the corners round. I just want to make the corners of green container round.

class MyPainter extends CustomPainter {
  @override
  void paint(Canvas canvas, Size size) {
    var paint = Paint()
      ..color = Colors.green.withOpacity(0.8)
      ..strokeWidth = 5
      ..strokeCap = StrokeCap.round;

    final shapeBounds = Rect.fromLTRB(0, 0, size.width, size.height);

    final path = Path()
      ..moveTo(shapeBounds.left + 10, shapeBounds.top) //3
      ..lineTo(shapeBounds.bottomLeft.dx + 10,shapeBounds.bottomLeft.dy) 
      ..lineTo(shapeBounds.bottomRight.dx,shapeBounds.bottomRight.dy - size.height * 0.12)
      ..lineTo(shapeBounds.topRight.dx - 20,
          shapeBounds.topRight.dy + size.height * 0.12) //7
      ..close();

    canvas.drawPath(path, paint);

  }

  @override
  bool shouldRepaint(CustomPainter oldDelegate) {
    // TODO: implement shouldRepaint
    return false;
  }
}

Answer 1

You can use ClipPath . Use a Custom Clipper in it. In the Custom Clipper, while drawing the path use quadraticBezierTo.

class MyContainer extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ClipPath(
      clipper: MyClipper(),
      child: Container(
        child: Text("Dummy Text"),
        alignment: Alignment.center,
        color: Colors.green,
        width: 200,
        height: 200,
      ),
    );
  }
}

class MyClipper extends CustomClipper<Path> {
  Path getClip(Size size) {
    final path = Path();
    path
      ..lineTo(0.0, size.height * 0.1)
      ..quadraticBezierTo(0, 0, size.width * 0.1, 0)
      ..lineTo(size.width * 0.8, size.height * 0.12)
      ..quadraticBezierTo(size.width * 0.9, size.height * 0.15,
          size.width * 0.9, size.height * 0.2)
      ..lineTo(size.width, size.height * 0.9)
      ..quadraticBezierTo(
          size.width, size.height, size.width * 0.9, size.height)
      ..lineTo(size.width * 0.2, size.height * 0.9)
      ..quadraticBezierTo(size.width * 0.1, size.height * 0.9, size.width * 0.1,
          size.height * 0.8)
      ..close();
    return path;
  }

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

Answer 2

Rather than using Rect which gives you a normal rectangle use RRect which will give the desired rounded rectangle, comment if you need a demo code.

Answer 3

if you want a rounded edge in all corners.

Container(
  decoration:BoxDecoration(
     borderRadius:BorderRadius.circular(double radius)
   )
)

if you want a rounded edge in a particular corner.

 Container(
  decoration:BoxDecoration(
     borderRadius:BorderRadius.only(
       topLeft:Radius.circular()
       topRight :Radius.circular()
       bottomLeft :Radius.circular()
       bottomRight :Radius.circular()

      )
   )
)

For more details check out this link: https://api.flutter.dev/flutter/painting/BorderRadius-class.html