MyArc
的StatelessWidget
,它接受一个diameter
参数。import 'dart:math' as math;
class MyArc extends StatelessWidget {
final double diameter;
const MyArc({super.key, this.diameter = 200});
@override
Widget build(BuildContext context) {
return CustomPaint(
painter: MyPainter(),
size: Size(diameter, diameter),
);
}
}
// This is the Painter class
class MyPainter extends CustomPainter {
@override
void paint(Canvas canvas, Size size) {
Paint paint = Paint()..color = Colors.blue;
canvas.drawArc(
Rect.fromCenter(
center: Offset(size.height / 2, size.width / 2),
height: size.height,
width: size.width,
),
math.pi,
math.pi,
false,
paint,
);
}
@override
bool shouldRepaint(CustomPainter oldDelegate) => false;
}
用法:
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(),
body: MyArc(diameter: 300),
);
}
Container(
decoration: const BoxDecoration(
color: Colors.black,
borderRadius: BorderRadius.only(
bottomLeft: Radius.circular(100),
bottomRight: Radius.circular(100),
),
使用此代码可以制作半圆形。
ClipPath(
clipper: CustomClip(),
child: Container(
width: 200,
height: 100,
color: Colors.blue,
),
),
class CustomClip extends CustomClipper<Path> {
@override
Path getClip(Size size) {
double radius = 100;
Path path = Path();
path
..moveTo(size.width / 2, 0)
..arcToPoint(Offset(size.width, size.height),
radius: Radius.circular(radius))
..lineTo(0, size.height)
..arcToPoint(
Offset(size.width / 2, 0),
radius: Radius.circular(radius),
)
..close();
return path;
}
@override
bool shouldReclip(covariant CustomClipper<Path> oldClipper) {
return true;
}
}
更新:你只需要一个容器
,非常简单:
Container(
decoration: BoxDecoration(
borderRadius: BorderRadius.only(
bottomLeft: Radius.circular(100),
topLeft: Radius.circular(100)),
color: Colors.red,
shape: BoxShape.rectangle,
),
height: 35,
width: 35,
),
这里是一个使用 Stack
的简单代码。您可以使用矩形和圆形轻松生成半圆。使用 BoxDecoration(shape:)
重新塑造容器。
Stack(
children: [
Align(
alignment: Alignment.center,
child: Container(
height: 35,
width: 35,
decoration: BoxDecoration(
color: Colors.red,
shape: BoxShape.circle,
),
),
),
Align(
alignment: Alignment.centerLeft,
child: Container(
decoration: BoxDecoration(
color: Colors.red,
shape: BoxShape.rectangle,
),
height: 35,
width: 35,
),
),
],
),
使用简单的实现方式(不是最佳实践),您可以在一行中绘制两个具有相同宽度和高度的容器, 并为每个容器提供 BoxDectoration => BorderRadius,如下所示:
这不是最佳实现方法,但它可以正常工作。
Row(children: [
Container(
decoration: BoxDecoration(
borderRadius: BorderRadius.only(topRight: Radius.circular(200),),
color: Colors.blue[300],
),
width: 200,
height: 200,
),
Container(
decoration: BoxDecoration(
borderRadius: BorderRadius.only(topLeft: Radius.circular(200),),
color: Colors.blue[300],
),
width: 200,
height: 200,
)
], ),
这个会有效,你可以更改尺寸,但确保高度为borderRadius的一半,宽度等于borderRadius。
Container(
height: 50,
width:100,
decoration: const BoxDecoration(
color: Colors.black,
borderRadius: BorderRadius.only(
bottomLeft: Radius.circular(100),
bottomRight: Radius.circular(100),
))),
LinearGradient
作为颜色添加到绘图类中? - user2511882Paint
对象上使用Shader
。 - CopsOnRoaddrawArc
的第三个参数中使用-math.pi
。 - CopsOnRoad