Swift NSImage to CGImage

Question

Come posso convertire un NSImage in CGImage in Swift? In Objective-C che ho fatto in questo modo:

- (CGImageRef)CGImage { 
    NSData *imageData = self.TIFFRepresentation; 
    CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef)imageData, NULL); 
    CGImageRef maskRef = CGImageSourceCreateImageAtIndex(source, 0, NULL); 
    return maskRef; 
} 

Ora ho provato con:

extension NSImage { 
    var CGImage: CGImageRef { 
    get { 
     let imageData = self.TIFFRepresentation 
     let source = CGImageSourceCreateWithData(imageData as CFDataRef, nil) 
     let maskRef = CGImageSourceCreateImageAtIndex(source, UInt(0), nil) 
     return maskRef; 
    } 
    } 
} 

non riesco a compilare, sto ottenendo l'errore: Could not find an overload for 'init' that accepts the supplied arguments' alla linea let maskRef ...

Answer 1

Ah, ho trovato la soluzione. È perché in Swift hai solo un oggetto non gestito (non ho proprio capito, cosa significa). Ma questo codice funziona ora:

extension NSImage { 
    var CGImage: CGImageRef { 
    get { 
     let imageData = self.TIFFRepresentation 
     let source = CGImageSourceCreateWithData(imageData as CFDataRef, nil).takeUnretainedValue() 
     let maskRef = CGImageSourceCreateImageAtIndex(source, UInt(0), nil) 
     return maskRef.takeUnretainedValue(); 
    } 
    } 
} 

Answer 2

Ecco quello che sto usando per convertire NSImage a CGImage:

let image = NSImage(named:"image") 
if let image = image { 
    var imageRect:CGRect = CGRectMake(0, 0, image.size.width, image.size.height) 
    var imageRef = image.CGImageForProposedRect(&imageRect, context: nil, hints: nil) 
} 

Answer 3

Swift codice 3 e 4 versione: -

if let image = NSImage(named: "Icon"){ 
    let cgImage = image.cgImage(forProposedRect: nil, context: nil, hints: nil) 
}