Ios 来自UIIMagePicker的图像被旋转

我需要从uiimagepicker获取图像，并需要在uiimageview中显示。它在模拟器中工作正常。但在设备上，uiimagepicker的图像是旋转的。如何解决此问题？

此问题是由于手机摄像头的纵向/横向方向造成的。像这样重新旋转图像

CGImageRef imageRef = [sourceImage CGImage];

UIImage *rotatedImage = [UIImage imageWithCGImage:imageRef scale:1.0 orientation:UIImageOrientationUp];

或者试试这样的

static inline double radians (double degrees) {return degrees * M_PI/180;}
UIImage* rotate(UIImage* src, UIImageOrientation orientation)
{
    UIGraphicsBeginImageContext(src.size);

    CGContextRef context = UIGraphicsGetCurrentContext();

    if (orientation == UIImageOrientationRight) {
        CGContextRotateCTM (context, radians(90));
    } else if (orientation == UIImageOrientationLeft) {
        CGContextRotateCTM (context, radians(-90));
    } else if (orientation == UIImageOrientationDown) {
        // NOTHING
    } else if (orientation == UIImageOrientationUp) {
        CGContextRotateCTM (context, radians(90));
    }

    [src drawAtPoint:CGPointMake(0, 0)];

    return UIGraphicsGetImageFromCurrentImageContext();
}

---

在使用图像之前确定图像的方向。 使用下面的扩展来固定UIImage方向

extension UIImage {
    
    /// Fix image orientaton to protrait up
    func fixedOrientation() -> UIImage? {
        guard imageOrientation != UIImage.Orientation.up else {
            // This is default orientation, don't need to do anything
            return self.copy() as? UIImage
        }
        
        guard let cgImage = self.cgImage else {
            // CGImage is not available
            return nil
        }
        
        guard let colorSpace = cgImage.colorSpace, let ctx = CGContext(data: nil, width: Int(size.width), height: Int(size.height), bitsPerComponent: cgImage.bitsPerComponent, bytesPerRow: 0, space: colorSpace, bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue) else {
            return nil // Not able to create CGContext
        }
        
        var transform: CGAffineTransform = CGAffineTransform.identity
        
        switch imageOrientation {
        case .down, .downMirrored:
            transform = transform.translatedBy(x: size.width, y: size.height)
            transform = transform.rotated(by: CGFloat.pi)
        case .left, .leftMirrored:
            transform = transform.translatedBy(x: size.width, y: 0)
            transform = transform.rotated(by: CGFloat.pi / 2.0)
        case .right, .rightMirrored:
            transform = transform.translatedBy(x: 0, y: size.height)
            transform = transform.rotated(by: CGFloat.pi / -2.0)
        case .up, .upMirrored:
            break
        @unknown default:
            break
        }
        
        // Flip image if needed to, this is to prevent flipped image
        switch imageOrientation {
        case .upMirrored, .downMirrored:
            transform = transform.translatedBy(x: size.width, y: 0)
            transform = transform.scaledBy(x: -1, y: 1)
        case .leftMirrored, .rightMirrored:
            transform = transform.translatedBy(x: size.height, y: 0)
            transform = transform.scaledBy(x: -1, y: 1)
        case .up, .down, .left, .right:
            break
        @unknown default:
            break
        }
        
        ctx.concatenate(transform)
        
        switch imageOrientation {
        case .left, .leftMirrored, .right, .rightMirrored:
            ctx.draw(cgImage, in: CGRect(x: 0, y: 0, width: size.height, height: size.width))
        default:
            ctx.draw(cgImage, in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
            break
        }
        
        guard let newCGImage = ctx.makeImage() else { return nil }
        return UIImage.init(cgImage: newCGImage, scale: 1, orientation: .up)
    }
}

用法：

let fixedImage = myImage.fixedOrientation()

---

将其重新旋转到原始位置这完全没有必要。OP可能正在将图像保存为PNG并放弃其方向。所需要的只是使用JPEG而不是PNG。顺便说一句，为什么不简单地

返回self

而不是

返回self.copy（）？UIImage

？