如何制作一个 ellipse/circular 具有透明背景的 UIImage?
How to make an ellipse/circular UIImage with transparent background?
这是我正在使用的代码
extension UIImage {
var ellipseMasked: UIImage? {
guard let cgImage = cgImage else { return nil }
let rect = CGRect(origin: .zero, size: size)
return UIGraphicsImageRenderer(size: size, format: imageRendererFormat)
.image{ _ in
UIBezierPath(ovalIn: rect).addClip()
UIImage(cgImage: cgImage, scale: scale, orientation: imageOrientation)
.draw(in: rect)
}
}
}
这是我得到的图片
背景颜色为黑色。
如何使背景透明?
我尝试了不同的方法,但还没有成功。
您可以子类化 UIImageView 并屏蔽其 CALayer 而不是裁剪图像本身:
extension CAShapeLayer {
convenience init(path: UIBezierPath) {
self.init()
self.path = path.cgPath
}
}
class EllipsedView: UIImageView {
override func layoutSubviews() {
super.layoutSubviews()
layer.mask = CAShapeLayer(path: .init(ovalIn: bounds))
}
}
let profilePicture = UIImage(data: try! Data(contentsOf: URL(string:"http://i.stack.imgur.com/Xs4RX.jpg")!))!
let iv = EllipsedView(image: profilePicture)
edit/update
如果您需要剪辑 UIImage
本身,您可以按以下方式进行:
extension UIImage {
var ellipseMasked: UIImage? {
UIGraphicsBeginImageContextWithOptions(size, false, scale)
defer { UIGraphicsEndImageContext() }
UIBezierPath(ovalIn: .init(origin: .zero, size: size)).addClip()
draw(in: .init(origin: .zero, size: size))
return UIGraphicsGetImageFromCurrentImageContext()
}
}
对于 iOS10+ 你可以使用 UIGraphicsImageRenderer
.
extension UIImage {
var ellipseMasked: UIImage {
let rect = CGRect(origin: .zero, size: size)
let format = imageRendererFormat
format.opaque = false
return UIGraphicsImageRenderer(size: size, format: format).image{ _ in
UIBezierPath(ovalIn: rect).addClip()
draw(in: rect)
}
}
}
let profilePicture = UIImage(data: try! Data(contentsOf: URL(string:"http://i.stack.imgur.com/Xs4RX.jpg")!))!
profilePicture.ellipseMasked
这是我正在使用的代码
extension UIImage {
var ellipseMasked: UIImage? {
guard let cgImage = cgImage else { return nil }
let rect = CGRect(origin: .zero, size: size)
return UIGraphicsImageRenderer(size: size, format: imageRendererFormat)
.image{ _ in
UIBezierPath(ovalIn: rect).addClip()
UIImage(cgImage: cgImage, scale: scale, orientation: imageOrientation)
.draw(in: rect)
}
}
}
这是我得到的图片
背景颜色为黑色。 如何使背景透明? 我尝试了不同的方法,但还没有成功。
您可以子类化 UIImageView 并屏蔽其 CALayer 而不是裁剪图像本身:
extension CAShapeLayer {
convenience init(path: UIBezierPath) {
self.init()
self.path = path.cgPath
}
}
class EllipsedView: UIImageView {
override func layoutSubviews() {
super.layoutSubviews()
layer.mask = CAShapeLayer(path: .init(ovalIn: bounds))
}
}
let profilePicture = UIImage(data: try! Data(contentsOf: URL(string:"http://i.stack.imgur.com/Xs4RX.jpg")!))!
let iv = EllipsedView(image: profilePicture)
edit/update
如果您需要剪辑 UIImage
本身,您可以按以下方式进行:
extension UIImage {
var ellipseMasked: UIImage? {
UIGraphicsBeginImageContextWithOptions(size, false, scale)
defer { UIGraphicsEndImageContext() }
UIBezierPath(ovalIn: .init(origin: .zero, size: size)).addClip()
draw(in: .init(origin: .zero, size: size))
return UIGraphicsGetImageFromCurrentImageContext()
}
}
对于 iOS10+ 你可以使用 UIGraphicsImageRenderer
.
extension UIImage {
var ellipseMasked: UIImage {
let rect = CGRect(origin: .zero, size: size)
let format = imageRendererFormat
format.opaque = false
return UIGraphicsImageRenderer(size: size, format: format).image{ _ in
UIBezierPath(ovalIn: rect).addClip()
draw(in: rect)
}
}
}
let profilePicture = UIImage(data: try! Data(contentsOf: URL(string:"http://i.stack.imgur.com/Xs4RX.jpg")!))!
profilePicture.ellipseMasked