ios - OSX UIGraphicsBeginImageContext

Question

我现在正在为 Mac OSX 创建一个 iOS 应用程序。我有下面的代码，将图像转换为 1024 的大小，并根据图像的长宽比计算出宽度。这适用于 iOS，但显然不适用于 OSX。我不确定如何创建 NSImage 的 PNG 表示形式，也不知道应该使用什么来代替 UIGraphicsBeginImageContext。有什么建议么？ 谢谢。

        var image = myImageView.image

        let imageData = UIImagePNGRepresentation(image)
        let imageWidth = image?.size.width
        let calculationNumber:CGFloat = imageWidth! / 1024.0

        let imageHeight = image?.size.height
        let newImageHeight = imageHeight! / calculationNumber

        UIGraphicsBeginImageContext(CGSizeMake(1024.0, newImageHeight))
        image?.drawInRect(CGRectMake(0, 0, 1024.0, newImageHeight))
        var resizedImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        let imageData = UIImagePNGRepresentation(resizedImage)

        let theImageData:NSData = UIImagePNGRepresentation(resizedImage)
        imageFile = PFFile(data: theImageData)

Answer 1

您可以使用:

let image = NSImage(size: newSize)
image.lockFocus()
//draw your stuff here
image.unlockFocus()
if let data = image?.TIFFRepresentation {
    let imageRep = NSBitmapImageRep(data: data)
    let imageData = imageRep?.representationUsingType(NSBitmapImageFileType.NSPNGFileType, properties: [:])
    //do something with your PNG data here
}