从CALayer或NSView获取图像(swift 3) [英] Get Image from CALayer or NSView (swift 3)
问题描述
我一直在寻找一种渲染CALayer或NSView并重新获得NSImage的方法.
I was looking for a way to render CALayer or NSView and get NSImage back.
我有一个自定义类,它是NSView的子类. 一开始,我只是简单地创建了一个渐变层以覆盖所有NSView.
I have a custom class which is a subclass of NSView. In the beginning I simply make a gradient layer to cover all NSView.
class ContentView: NSView {
override func draw(_ dirtyRect: NSRect) {
fillGradientLayer()
}
func fillGradientLayer() {
gradientLayer = CAGradientLayer()
gradientLayer.colors = [#colorLiteral(red: 0, green: 0.9909763549, blue: 0.7570167824, alpha: 1),#colorLiteral(red: 0, green: 0.4772562545, blue: 1, alpha: 1)].map({return $0.cgColor})
gradientLayer.startPoint = CGPoint(x: 0, y: 0.5)
gradientLayer.endPoint = CGPoint(x: 1, y: 0.5)
gradientLayer.frame = self.frame.insetBy(dx: margin, dy: margin)
gradientLayer.zPosition = 2
gradientLayer.name = "gradientLayer"
gradientLayer.contentsScale = (NSScreen.main()?.backingScaleFactor)!
self.layer?.addSublayer(gradientLayer)
}
}
在某个时候,我想从 CALayer s获得NSImage(或CGImage). 在某些主题中,我找到了下一种方法,并将其变成了这样:
At some point I want to get NSImage (or CGImage) from of CALayers. In some topics I found the next approach and turned it into this:
extension CALayer {
func getBitmapImage() -> NSImage {
let btmpImgRep = NSBitmapImageRep(bitmapDataPlanes: nil, pixelsWide: Int(self.frame.width), pixelsHigh: Int(self.frame.height), bitsPerSample: 8, samplesPerPixel: 4, hasAlpha: true, isPlanar: false, colorSpaceName: NSDeviceRGBColorSpace, bytesPerRow: 0, bitsPerPixel: 0)
let image: NSImage = NSImage(size: self.frame.size)
image.lockFocus()
let ctx = NSGraphicsContext(bitmapImageRep: btmpImgRep!)
let cgCtxt = ctx!.cgContext
self.render(in: cgCtxt)
cgCtxt.draw(layer: CGLayer, in: CGRect)
image.unlockFocus()
return image
}
}
第一个问题是 draw(layer:CGLayer,in:CGRect) 方法需要CGLayer而不是CALayer.
The first problem is that draw(layer: CGLayer, in: CGRect) method wants CGLayer but not CALayer.
第二,我不知道最终生成的代码是否最终会渲染我的图层,或者我做错了什么.
Secondly, I don't know if the code I ended up with will eventually render my layer or I'm doing something wrong.
感谢您的帮助.
已 从CALayer获取CGImage的解决方案.
Edited: Solution to get a CGImage from CALayer.
extension CALayer {
func getBitmapImage() -> NSImage {
let btmpImgRep =
NSBitmapImageRep(bitmapDataPlanes: nil, pixelsWide: Int(self.frame.width), pixelsHigh: Int(self.frame.height), bitsPerSample: 8, samplesPerPixel: 4, hasAlpha: true, isPlanar: false, colorSpaceName: NSDeviceRGBColorSpace, bytesPerRow: 0, bitsPerPixel: 32)
let ctx = NSGraphicsContext(bitmapImageRep: btmpImgRep!)
let cgContext = ctx!.cgContext
self.render(in: cgContext)
let cgImage = cgContext.makeImage()
let nsimage = NSImage(cgImage: cgImage!, size: CGSize(width: self.frame.width, height: self.frame.height))
return nsimage
}
}
下面的答案中如何从NSView获取NSImage.
How to get NSImage from NSView is in the answer below.
P.S.我不知道NSBitmapImageRep属性,所以这部分可能是错误的.
推荐答案
以下是一些NSView
选项:
extension NSView {
/// Get `NSImage` representation of the view.
///
/// - Returns: `NSImage` of view
func image() -> NSImage {
let imageRepresentation = bitmapImageRepForCachingDisplay(in: bounds)!
cacheDisplay(in: bounds, to: imageRepresentation)
return NSImage(cgImage: imageRepresentation.cgImage!, size: bounds.size)
}
}
或
extension NSView {
/// Get `Data` representation of the view.
///
/// - Parameters:
/// - fileType: The format of file. Defaults to PNG.
/// - properties: A dictionary that contains key-value pairs specifying image properties.
/// - Returns: `Data` for image.
func data(using fileType: NSBitmapImageFileType = .PNG, properties: [String : Any] = [:]) -> Data {
let imageRepresentation = bitmapImageRepForCachingDisplay(in: bounds)!
cacheDisplay(in: bounds, to: imageRepresentation)
return imageRepresentation.representation(using: fileType, properties: properties)!
}
}
某些CALayer
选项:
Some CALayer
options:
extension CALayer {
/// Get `NSImage` representation of the layer.
///
/// - Returns: `NSImage` of the layer.
func image() -> NSImage {
let width = Int(bounds.width * self.contentsScale)
let height = Int(bounds.height * self.contentsScale)
let imageRepresentation = NSBitmapImageRep(bitmapDataPlanes: nil, pixelsWide: width, pixelsHigh: height, bitsPerSample: 8, samplesPerPixel: 4, hasAlpha: true, isPlanar: false, colorSpaceName: NSDeviceRGBColorSpace, bytesPerRow: 0, bitsPerPixel: 0)!
imageRepresentation.size = bounds.size
let context = NSGraphicsContext(bitmapImageRep: imageRepresentation)!
render(in: context.cgContext)
return NSImage(cgImage: imageRepresentation.cgImage!, size: bounds.size)
}
}
或
extension CALayer {
/// Get `Data` representation of the layer.
///
/// - Parameters:
/// - fileType: The format of file. Defaults to PNG.
/// - properties: A dictionary that contains key-value pairs specifying image properties.
///
/// - Returns: `Data` for image.
func data(using fileType: NSBitmapImageFileType = .PNG, properties: [String : Any] = [:]) -> Data {
let width = Int(bounds.width * self.contentsScale)
let height = Int(bounds.height * self.contentsScale)
let imageRepresentation = NSBitmapImageRep(bitmapDataPlanes: nil, pixelsWide: width, pixelsHigh: height, bitsPerSample: 8, samplesPerPixel: 4, hasAlpha: true, isPlanar: false, colorSpaceName: NSDeviceRGBColorSpace, bytesPerRow: 0, bitsPerPixel: 0)!
imageRepresentation.size = bounds.size
let context = NSGraphicsContext(bitmapImageRep: imageRepresentation)!
render(in: context.cgContext)
return imageRepresentation.representation(using: fileType, properties: properties)!
}
}
这篇关于从CALayer或NSView获取图像(swift 3)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!