将UIImage切成一个圆Swift（iOS）
我想把一个UIImage切成一个圆，这样我就可以用它作为注释。 我发现这个网站上的每一个答案都描述了创build一个UIImageView ，然后修改并显示它，但是你不能将一个注释的图像设置为一个UIImageView ，只有一个UIImage 。 我应该怎么做呢？
确保在需要时导入QuarzCore。
func maskRoundedImage(image: UIImage, radius: CGFloat) -> UIImage { let imageView: UIImageView = UIImageView(image: image) let layer = imageView.layer layer.masksToBounds = true layer.cornerRadius = radius UIGraphicsBeginImageContext(imageView.bounds.size) layer.render(in: UIGraphicsGetCurrentContext()!) let roundedImage = UIGraphicsGetImageFromCurrentImageContext() UIGraphicsEndImageContext() return roundedImage! }
Xcode 8.2•Swift 3.0.2
extension UIImage { var isPortrait: Bool { return size.height > size.width } var isLandscape: Bool { return size.width > size.height } var breadth: CGFloat { return min(size.width, size.height) } var breadthSize: CGSize { return CGSize(width: breadth, height: breadth) } var breadthRect: CGRect { return CGRect(origin: .zero, size: breadthSize) } var circleMasked: UIImage? { UIGraphicsBeginImageContextWithOptions(breadthSize, false, scale) defer { UIGraphicsEndImageContext() } guard let cgImage = cgImage?.cropping(to: CGRect(origin: CGPoint(x: isLandscape ? floor((size.width - size.height) / 2) : 0, y: isPortrait ? floor((size.height - size.width) / 2) : 0), size: breadthSize)) else { return nil } UIBezierPath(ovalIn: breadthRect).addClip() UIImage(cgImage: cgImage, scale: 1, orientation: imageOrientation).draw(in: breadthRect) return UIGraphicsGetImageFromCurrentImageContext() } }
游乐场testing
let profilePicture = UIImage(data: try! Data(contentsOf: URL(string:"http://i.stack.imgur.com/Xs4RX.jpg")!))! profilePicture.circleMasked
UIImage扩展：
extension UIImage { func circularImage(size size: CGSize?) -> UIImage { let newSize = size ?? self.size let minEdge = min(newSize.height, newSize.width) let size = CGSize(width: minEdge, height: minEdge) UIGraphicsBeginImageContextWithOptions(size, false, 0.0) let context = UIGraphicsGetCurrentContext() self.drawInRect(CGRect(origin: CGPoint.zero, size: size), blendMode: .Copy, alpha: 1.0) CGContextSetBlendMode(context, .Copy) CGContextSetFillColorWithColor(context, UIColor.clearColor().CGColor) let rectPath = UIBezierPath(rect: CGRect(origin: CGPoint.zero, size: size)) let circlePath = UIBezierPath(ovalInRect: CGRect(origin: CGPoint.zero, size: size)) rectPath.appendPath(circlePath) rectPath.usesEvenOddFillRule = true rectPath.fill() let result = UIGraphicsGetImageFromCurrentImageContext() UIGraphicsEndImageContext() return result } }
用法：
的UIImageView：
@IBDesignable class CircularImageView: UIImageView { override var image: UIImage? { didSet { super.image = image?.circularImage(size: nil) } } }
的UIButton：
@IBDesignable class CircularImageButton: UIButton { override func setImage(image: UIImage?, forState state: UIControlState) { let circularImage = image?.circularImage(size: nil) super.setImage(circularImage, forState: state) } }
Xcode 8.1，Swift 3.0.1
我的代码如下所示：
let image = yourImage.resize(CGSize(width: 20, height: 20))?.circled(forRadius: 20)
添加UIImage扩展，然后：
func resize(_ size: CGSize) -> UIImage? { let rect = CGRect(origin: .zero, size: size) return redraw(in: rect) } func redraw(in rect: CGRect) -> UIImage? { UIGraphicsBeginImageContextWithOptions(rect.size, false, UIScreen.main.scale) guard let context = UIGraphicsGetCurrentContext(), let cgImage = cgImage else { return nil } let rect = CGRect(origin: .zero, size: size) let flipVertical = CGAffineTransform(a: 1, b: 0, c: 0, d: -1, tx: 0, ty: rect.size.height) context.concatenate(flipVertical) context.draw(cgImage, in: rect) let image = UIGraphicsGetImageFromCurrentImageContext() UIGraphicsEndImageContext() return image } func circled(forRadius radius: CGFloat) -> UIImage? { let rediusSize = CGSize(width: radius, height: radius) let rect = CGRect(origin: .zero, size: size) UIGraphicsBeginImageContextWithOptions(size, false, UIScreen.main.scale) guard let context = UIGraphicsGetCurrentContext(), let cgImage = cgImage else { return nil } let flipVertical = CGAffineTransform(a: 1, b: 0, c: 0, d: -1, tx: 0, ty: rect.size.height) context.concatenate(flipVertical) let bezierPath = UIBezierPath(roundedRect: rect, byRoundingCorners: [.allCorners], cornerRadii: rediusSize) context.addPath(bezierPath.cgPath) context.clip() context.drawPath(using: .fillStroke) context.draw(cgImage, in: rect) let image = UIGraphicsGetImageFromCurrentImageContext() UIGraphicsEndImageContext() return image }
我设法通过findBezierPath的使用来回答我自己的问题！
if let xyz = UIImage(contentsOfFile: readPath) { var Rect: CGRect = CGRectMake(0, 0, xyz.size.width, xyz.size.height) var x = UIBezierPath(roundedRect: Rect, cornerRadius: 200).addClip() UIGraphicsBeginImageContextWithOptions(xyz.size, false, xyz.scale) xyz.drawInRect(Rect) var ImageNew = UIGraphicsGetImageFromCurrentImageContext() UIGraphicsEndImageContext() annotation.image = ImageNew }
您可以使用此代码来圈选图片
extension UIImage { func circleImage(_ cornerRadius: CGFloat, size: CGSize) -> UIImage? { let rect = CGRect(x: 0, y: 0, width: size.width, height: size.height) UIGraphicsBeginImageContextWithOptions(size, false, 0) if let context = UIGraphicsGetCurrentContext() { var path: UIBezierPath if size.height == size.width { if cornerRadius == size.width/2 { path = UIBezierPath(arcCenter: CGPoint(x: size.width/2, y: size.height/2), radius: cornerRadius, startAngle: 0, endAngle: 2.0*CGFloat(Double.pi), clockwise: true) }else { path = UIBezierPath(roundedRect: rect, cornerRadius: cornerRadius) } }else { path = UIBezierPath(roundedRect: rect, cornerRadius: cornerRadius) } context.addPath(path.cgPath) context.clip() self.draw(in: rect) // 从上下文上获取剪裁后的照片guard let uncompressedImage = UIGraphicsGetImageFromCurrentImageContext() else { UIGraphicsEndImageContext() return nil } // closures上下文UIGraphicsEndImageContext() return uncompressedImage }else { return nil } }}
