swift - 将方向应用于 CGContext

Question

我正在使用以下代码缩小UIImage:

let image = UIImage(contentsOfFile: imageUrl.path!)!.CGImage

                let width = Float(CGImageGetWidth(image)) / 1.01
                let height = Float(CGImageGetHeight(image)) / 1.01
                let bitsPerComponent = CGImageGetBitsPerComponent(image)
                let bytesPerRow = CGImageGetBytesPerRow(image)
                let colorSpace = CGImageGetColorSpace(image)
                let bitmapInfo = CGImageGetBitmapInfo(image)

                let context = CGBitmapContextCreate(nil, Int(width), Int(height), bitsPerComponent, bytesPerRow, colorSpace, bitmapInfo)
                CGContextSetInterpolationQuality(context, kCGInterpolationHigh)

                CGContextDrawImage(context, CGRect(origin: CGPointZero, size: CGSize(width: CGFloat(width), height: CGFloat(height))), image)

                let scaledImage = UIImage(CGImage: CGBitmapContextCreateImage(context))

它用于照片扩展。它可以工作，缩放输入图像，但不考虑方向。编辑开始时我保持方向:

func startContentEditingWithInput(contentEditingInput: PHContentEditingInput?, placeholderImage: UIImage) {

        let output = PHContentEditingOutput(contentEditingInput: self.input)
        let url = self.input?.fullSizeImageURL
        if let imageUrl = url {
           imageOrientation = input!.fullSizeImageOrientation
        }

}

保存的输出始终是横向的。

Answer 1

最简单的解决方案是在创建 UIImage 输出时重新使用 UIImage 输入中的图像方向。

let uiImage = UIImage(contentsOfFile: imageUrl.path!)
let image = uiImage!.CGImage
// ...
let scaledImage = UIImage(CGImage: CGBitmapContextCreateImage(context),
                          scale: uiImage.scale,
                          orientation: uiImage.imageOrientation)