swift - 根据 UIBezier 切割 UIImageView？

Question

我有一个 UIImageView，带有特定的图像。我还有一个形状奇怪的 UIBezierPath。我想将图像剪切成该形状并返回该形状的新图像。

形式为:

func getCut(bezier:UIBezierPath, image:UIImageView)->UIImageView

Answer 1

您可以使用掩码 来做到这一点。这是一个简单的例子。

class ViewController: UIViewController {

    var path: UIBezierPath!
    var touchPoint: CGPoint!
    var startPoint: CGPoint!

    var imageView =  UIImageView(image: #imageLiteral(resourceName: "IMG_0715"))

    override func viewDidLoad() {
        super.viewDidLoad()
        view.addSubview(imageView)
    }

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        if let touch = touches.first {
            startPoint = touch.location(in: view)
            path = UIBezierPath()
            path.move(to: startPoint)
        }
    }

    override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
        if let touch = touches.first {
            touchPoint = touch.location(in: view)
        }

        path.addLine(to: touchPoint)
        startPoint = touchPoint

    }

    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
        cut()
    }

    private func cut() {
        guard let path = path else { return }
        imageView = imageView.getCut(with: path)
    }

}

extension UIImageView {
    func getCut(with bezier: UIBezierPath) -> UIImageView {

        let shapeLayer = CAShapeLayer()
        shapeLayer.path = bezier.cgPath

        self.layer.mask = shapeLayer

        return self
    }
}