Swift-使用UIBezierPath剪切图像 [英] Swift - Clipping image with UIBezierPath

问题描述

我想从图像中剪切贝塞尔曲线路径.由于某些原因，图像保持未剪切状态.以及如何定位路径以使其正确切割?

I would like to clip a bezier path from an image. For some reason, the image remains the unclipped. And how do I position the path so it would be properly cut?

extension UIImage {

func imageByApplyingMaskingBezierPath(_ path: UIBezierPath, _ pathFrame: CGFrame) -> UIImage {

    UIGraphicsBeginImageContext(self.size)
    let context = UIGraphicsGetCurrentContext()!
    context.saveGState()

    path.addClip()
    draw(in: CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height))

    let maskedImage = UIGraphicsGetImageFromCurrentImageContext()!

    context.restoreGState()
    UIGraphicsEndImageContext()

    return maskedImage
}

}

推荐答案

您需要将 path.cgPath 添加到当前上下文中，还需要删除 context.saveGState()和 context.restoreGState()

You need to add your path.cgPath to your current context, also you need to remove context.saveGState() and context.restoreGState()

使用此代码

func imageByApplyingMaskingBezierPath(_ path: UIBezierPath, _ pathFrame: CGRect) -> UIImage {

            UIGraphicsBeginImageContext(self.size)
            let context = UIGraphicsGetCurrentContext()!

            context.addPath(path.cgPath)
            context.clip()
            draw(in: CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height))

            let maskedImage = UIGraphicsGetImageFromCurrentImageContext()!

            UIGraphicsEndImageContext()

            return maskedImage
        }

使用

let testPath = UIBezierPath()
testPath.move(to: CGPoint(x: self.imageView.frame.width / 2, y: self.imageView.frame.height))
testPath.addLine(to: CGPoint(x: 0, y: 0))
testPath.addLine(to: CGPoint(x: self.imageView.frame.width, y: 0))
testPath.close()

self.imageView.image = UIImage(named:"Image")?.imageByApplyingMaskingBezierPath(testPath, self.imageView.frame)

结果

这篇关于Swift-使用UIBezierPath剪切图像的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！