使用UIBezierPath点绘制矩形时如何对角进行舍入

Question

我使用UIBezierPath逐点添加一个矩形,现在我想要舍入这个矩形的角落,但似乎没有办法做到这一点.谁能帮我 ？

class RectangleLayer: CAShapeLayer {

    let animationDuration: CFTimeInterval = 0.5

    override init() {
        super.init()
        fillColor = Colors.clear.CGColor
        lineWidth = 5.0
        path = rectanglePathStart.CGPath
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
var rectanglePathStart: UIBezierPath {
        let rectanglePath = UIBezierPath()
        rectanglePath.moveToPoint(CGPoint(x: 0.0, y: 100.0))
        rectanglePath.addLineToPoint(CGPoint(x: 0.0, y: -lineWidth))
        rectanglePath.addLineToPoint(CGPoint(x: 100.0, y: -lineWidth))
        rectanglePath.addLineToPoint(CGPoint(x: 100.0, y: 100.0))
        rectanglePath.addLineToPoint(CGPoint(x: -lineWidth / 2, y: 100.0))

        rectanglePath.closePath()

//        fillColor = Colors.red.CGColor
        return rectanglePath
    }
}

Answer 1

如果你想要做的只是创建一个圆角矩形,那么你可以简单地使用

let rectangle = CGRect(x: 0, y: 0, width: 100, height: 100)
let path = UIBezierPath(roundedRect: rectangle, cornerRadius: 20)

如果你想要围绕一些角落,而不是其他角落,那么你可以使用

let rectangle = CGRect(x: 0, y: 0, width: 100, height: 100)
let path = UIBezierPath(roundedRect: rectangle, byRoundingCorners: [.TopLeft, .BottomRight], cornerRadii: CGSize(width: 35, height: 35))

如果要为每个角设置不同的角半径,则必须单独为每个圆添加弧.这归结为计算每个弧的中心和起始角和终止角.您会发现每个圆弧的中心都是从矩形的相应角落插入圆角半径.例如,左上角的中心

CGPoint(x: rectangle.minX + upperLeftRadius, y: rectangle.minY + upperLeftRadius)

每个弧的起始和结束角度可以是直线左,上,下或右.可以在UIBezierPath文档中看到与这些方向对应的角度.

如果你需要创建这样的多个矩形,你可以为它创建一个便利初始化器

extension UIBezierPath {
    convenience init(roundedRect rect: CGRect, topLeftRadius r1: CGFloat, topRightRadius r2: CGFloat, bottomRightRadius r3: CGFloat, bottomLeftRadius r4: CGFloat) {
        let left  = CGFloat(M_PI)
        let up    = CGFloat(1.5*M_PI)
        let down  = CGFloat(M_PI_2)
        let right = CGFloat(0.0)
        self.init()
        addArcWithCenter(CGPoint(x: rect.minX + r1, y: rect.minY + r1), radius: r1, startAngle: left,  endAngle: up,    clockwise: true)
        addArcWithCenter(CGPoint(x: rect.maxX - r2, y: rect.minY + r2), radius: r2, startAngle: up,    endAngle: right, clockwise: true)
        addArcWithCenter(CGPoint(x: rect.maxX - r3, y: rect.maxY - r3), radius: r3, startAngle: right, endAngle: down,  clockwise: true)
        addArcWithCenter(CGPoint(x: rect.minX + r4, y: rect.maxY - r4), radius: r4, startAngle: down,  endAngle: left,  clockwise: true)
        closePath()
    }
}

并像这样使用它

let path = UIBezierPath(roundedRect: rectangle, topLeftRadius: 30, topRightRadius: 10, bottomRightRadius: 15, bottomLeftRadius: 5)