iOS开发笔记-115:swift5，拍照和相册里选取的originalImage图片过大，会导致图片逆时针旋转90度

在拍照和从相册中获取图片，方式是originalImage的时候，图片会逆时针旋转90度。这个时候需要在上传前把图片恢复成正常。

代码：
image = image.fixOrientation()

Categorys:

import UIKit
 
extension UIImage {
    // 修复图片旋转
    func fixOrientation() -> UIImage {
        if self.imageOrientation == .up {
            return self
        }
         
        var transform = CGAffineTransform.identity
         
        switch self.imageOrientation {
        case .down, .downMirrored:
            transform = transform.translatedBy(x: self.size.width, y: self.size.height)
            transform = transform.rotated(by: .pi)
            break
             
        case .left, .leftMirrored:
            transform = transform.translatedBy(x: self.size.width, y: 0)
            transform = transform.rotated(by: .pi / 2)
            break
             
        case .right, .rightMirrored:
            transform = transform.translatedBy(x: 0, y: self.size.height)
            transform = transform.rotated(by: -.pi / 2)
            break
             
        default:
            break
        }
         
        switch self.imageOrientation {
        case .upMirrored, .downMirrored:
            transform = transform.translatedBy(x: self.size.width, y: 0)
            transform = transform.scaledBy(x: -1, y: 1)
            break
             
        case .leftMirrored, .rightMirrored:
            transform = transform.translatedBy(x: self.size.height, y: 0);
            transform = transform.scaledBy(x: -1, y: 1)
            break
             
        default:
            break
        }
         
        let ctx = CGContext(data: nil, width: Int(self.size.width), height: Int(self.size.height), bitsPerComponent: self.cgImage!.bitsPerComponent, bytesPerRow: 0, space: self.cgImage!.colorSpace!, bitmapInfo: self.cgImage!.bitmapInfo.rawValue)
        ctx?.concatenate(transform)
         
        switch self.imageOrientation {
        case .left, .leftMirrored, .right, .rightMirrored:
            ctx?.draw(self.cgImage!, in: CGRect(x: CGFloat(0), y: CGFloat(0), width: CGFloat(size.height), height: CGFloat(size.width)))
            break
             
        default:
            ctx?.draw(self.cgImage!, in: CGRect(x: CGFloat(0), y: CGFloat(0), width: CGFloat(size.width), height: CGFloat(size.height)))
            break
        }
         
        let cgimg: CGImage = (ctx?.makeImage())!
        let img = UIImage(cgImage: cgimg)
         
        return img
    }
}