迅速绘制视图背景的弧线

Question

我想在这样的视图的底部绘制一个弧形：

背景图案是另一回事，但是我认为可以通过uibezierpath之类的东西来完成吗？我没有太多经验，任何入门点吗？谢谢

Answer 1

将此自定义类分配给IB中的视图

class CurveView:UIView {

    var once = true

    override func layoutSubviews() {
        super.layoutSubviews()

        if once {

            let bb = UIBezierPath()

            bb.move(to: CGPoint(x: 0, y: self.frame.height))

            // the offset here is 40 you can play with it to increase / decrease the curve height

            bb.addQuadCurve(to: CGPoint(x: self.frame.width, y: self.frame.height), controlPoint: CGPoint(x: self.frame.width / 2 , y: self.frame.height + 40 ))

            bb.close()

            let l = CAShapeLayer()

            l.path = bb.cgPath

            l.fillColor =  self.backgroundColor!.cgColor

            self.layer.insertSublayer(l,at:0)

            once = false
        }

    }

}

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