iOS旋转照片问题

import UIKit
import ImageIO

func fixImageOrientation(image: UIImage) -> UIImage? {
    if image.imageOrientation == .up {
        return image
    }
    
    var transform = CGAffineTransform.identity
    switch image.imageOrientation {
    case .down, .downMirrored:
        transform = transform.translatedBy(x: image.size.width, y: image.size.height)
        transform = transform.rotated(by: .pi)
    case .left, .leftMirrored:
        transform = transform.translatedBy(x: image.size.width, y: 0)
        transform = transform.rotated(by: .pi / 2)
    case .right, .rightMirrored:
        transform = transform.translatedBy(x: 0, y: image.size.height)
        transform = transform.rotated(by: -.pi / 2)
    default:
        break
    }
    
    switch image.imageOrientation {
    case .upMirrored, .downMirrored:
        transform = transform.translatedBy(x: image.size.width, y: 0)
        transform = transform.scaledBy(x: -1, y: 1)
    case .leftMirrored, .rightMirrored:
        transform = transform.translatedBy(x: 0, y: image.size.height)
        transform = transform.scaledBy(x: 1, y: -1)
    default:
        break
    }
    
    guard let cgImage = image.cgImage else { return nil }
    let colorSpace = CGColorSpaceCreateDeviceRGB()
    let context = CGContext(data: nil, width: cgImage.width, height: cgImage.height, bitsPerComponent: 8, bytesPerRow: cgImage.bytesPerRow, space: colorSpace, bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue)!
    context.concatenate(transform)
    
    switch image.imageOrientation {
    case .left, .leftMirrored, .right, .rightMirrored:
        context.draw(cgImage, in: CGRect(x: 0, y: 0, width: image.size.height, height: image.size.width))
    default:
        context.draw(cgImage, in: CGRect(x: 0, y: 0, width: image.size.width, height: image.size.height))
    }
    
    guard let newCGImage = context.makeImage() else { return nil }
    return UIImage(cgImage: newCGImage)
}