Ios 如何仅填充CAShapeLayer上形状的一部分
我用UIBezierPath创建以下形状,然后用CAShapeLayer绘制它,如下所示Ios 如何仅填充CAShapeLayer上形状的一部分,ios,swift,uibezierpath,swift5,cashapelayer,Ios,Swift,Uibezierpath,Swift5,Cashapelayer,我用UIBezierPath创建以下形状,然后用CAShapeLayer绘制它,如下所示 // left Circle shapeLayer1.path = bezierPath1.cgPath shapeLayer1.fillColor = UIColor.blue.cgColor // line shapeLayer2.path = bezierPath2.cgPath // right Circle shapeLayer3.path = bezierPath3.cgPath shape
// left Circle
shapeLayer1.path = bezierPath1.cgPath
shapeLayer1.fillColor = UIColor.blue.cgColor
// line
shapeLayer2.path = bezierPath2.cgPath
// right Circle
shapeLayer3.path = bezierPath3.cgPath
shapeLayer3.fillColor = UIColor.clear.cgColor
self.view.layer.addSublayer(shapeLayer1)
self.view.layer.addSublayer(shapeLayer2)
self.view.layer.addSublayer(shapeLayer3)
然后我可以将CAShapeLayer fillColor属性从shapeLayer.fillColor=UIColor.clear.cgColor
更改为shapeLayer.fillColor=UIColor.blue.cgColor
,并获得以下形状
代码如下:
import UIKit
class ViewController: UIViewController {
var line = [CGPoint]()
let bezierPath: UIBezierPath = UIBezierPath()
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .white
let point1 = CGPoint(x: 100, y: 100)
let point2 = CGPoint(x: 400, y: 100)
line.append(point1)
line.append(point2)
addCircle(toRight: false)
addLine()
addCircle(toRight: true)
let shapeLayer = CAShapeLayer()
shapeLayer.path = bezierPath.cgPath
shapeLayer.strokeColor = UIColor.blue.cgColor
shapeLayer.fillColor = UIColor.clear.cgColor
self.view.layer.addSublayer(shapeLayer)
}
func addLine() -> Void {
bezierPath.move(to: line.first!)
bezierPath.addLine(to: line.last!)
}
func addCircle(toRight: Bool) -> Void {
let angle = CGFloat( Double.pi / 180 )
let r = CGFloat(20.0)
let x0 = toRight ? line.first!.x : line.last!.x
let y0 = toRight ? line.first!.y : line.last!.y
let x1 = toRight ? line.last!.x : line.first!.x
let y1 = toRight ? line.last!.y : line.first!.y
let x = x1 - x0
let y = y1 - y0
let h = (x*x + y*y).squareRoot()
let x2 = x0 + (x * (h + r) / h)
let y2 = y0 + (y * (h + r) / h)
// Add the arc, starting at that same point
let point2 = CGPoint(x: x2, y: y2)
let pointZeroDeg = CGPoint(x: x2 + r, y: y2)
self.bezierPath.move(to: pointZeroDeg)
self.bezierPath.addArc(withCenter: point2, radius: r,
startAngle: 0*angle, endAngle: 360*angle,
clockwise: true)
self.bezierPath.close()
}
}
但我真正想要的是下面的形状(左侧圆是填充的,右侧圆不是填充的)
所以我的问题是,如何只填充CAShapeLayer上的一部分形状?
可能吗?有什么诀窍可以做到这一点吗
PS:我可以通过创建3个不同的UIBezierPath(用于leftCircle、line和rightCircle)并使用3个不同的CashapeLayer绘制它们来实现这一点,如下所示
// left Circle
shapeLayer1.path = bezierPath1.cgPath
shapeLayer1.fillColor = UIColor.blue.cgColor
// line
shapeLayer2.path = bezierPath2.cgPath
// right Circle
shapeLayer3.path = bezierPath3.cgPath
shapeLayer3.fillColor = UIColor.clear.cgColor
self.view.layer.addSublayer(shapeLayer1)
self.view.layer.addSublayer(shapeLayer2)
self.view.layer.addSublayer(shapeLayer3)
但我更喜欢用一个CAShapeLayer来实现这一点 我认为更好的方法是使用多种形状 但是,您可以使用
evenOdd
形状填充规则来实现一个形状
只需在方法addCircle
中的右圆圈中添加一个额外的圆圈:
if toRight {
self.bezierPath.addArc(withCenter: point2, radius: r,
startAngle: 0*angle, endAngle: 2*360*angle,
clockwise: true)
} else {
self.bezierPath.addArc(withCenter: point2, radius: r,
startAngle: 0*angle, endAngle: 360*angle,
clockwise: true)
}
并将fillRule
设置为evenOdd
:
shapeLayer.fillColor = UIColor.blue.cgColor
shapeLayer.fillRule = .evenOdd
因此,您将得到左边的圆将有一个绘图圆,并将由evenOdd
规则填充。但右边的圆圈将有两个画圈,并且将不填充
evenOdd
规则():
指定奇偶缠绕规则。计算路径的总数
过境点。如果交叉口的数量为偶数,则该点位于外侧
这条路。如果交叉点的数量为奇数,则该点位于
路径和包含它的区域应该被填充