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试图用我的自定义遮罩遮罩图像。我认为我正确地按照the ideas，但由于某种原因，图像不被蒙上。取而代之的是，在蒙版后创建的蒙版图像包含原始裁剪图像，因为未应用蒙版。UIImage遮罩不起作用（Swift，iOS 10）
这里的哪一个可以为了用它来测试我的代码斯威夫特游乐场代码（图像和面罩连接，只需将它们拖放到资源文件夹）：
import UIKit
extension UIImage {
static func resizeImage(image: UIImage, width: CGFloat) -> UIImage {
let scale = width/image.size.width
let newHeight = round(image.size.height * scale)
UIGraphicsBeginImageContextWithOptions(CGSize(width:width, height:newHeight), false, image.scale)
image.draw(in: CGRect(origin: CGPoint(x:0, y:0), size: CGSize(width: width, height: newHeight)))
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage!
}
static func resizeImage(image: UIImage, height: CGFloat) -> UIImage {
let scale = height/image.size.height
let newWidth = round(image.size.width * scale)
UIGraphicsBeginImageContextWithOptions(CGSize(width:newWidth, height:height), false, image.scale)
image.draw(in: CGRect(origin: CGPoint(x:0, y:0), size: CGSize(width: newWidth, height: height)))
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage!
}
}
let image = UIImage(named: "image.jpg")!
var mask = UIImage(named: "mask.jpg")!
let k1 = image.size.width/image.size.height
let k2 = mask.size.width/mask.size.height
if k1 >= k2
{
mask = UIImage.resizeImage(image: mask, height: image.size.height)
}
else
{
mask = UIImage.resizeImage(image: mask, width: image.size.width)
}
image
mask
let center = CGPoint(x: image.size.width/2, y: image.size.height/2)
let croppingRect = CGRect(x: abs(image.size.width-mask.size.width)/2*image.scale,
y: abs(image.size.height-mask.size.height)/2*image.scale,
width: mask.size.width*image.scale,
height: mask.size.height*image.scale).integral
let maskReference = mask.cgImage!
let imageReference = image.cgImage!.cropping(to: croppingRect)!
let imageMask = CGImage(maskWidth: maskReference.width,
height: maskReference.height,
bitsPerComponent: maskReference.bitsPerComponent,
bitsPerPixel: maskReference.bitsPerPixel,
bytesPerRow: maskReference.bytesPerRow,
provider: maskReference.dataProvider!, decode: nil, shouldInterpolate: true)
imageMask?.colorSpace
imageMask?.alphaInfo
let maskedReference = imageReference.masking(imageMask!)
let maskedImage = UIImage(cgImage:maskedReference!, scale: image.scale, orientation: image.imageOrientation)
