Question

我需要从uiimagepicker获取图像并需要在uiimageview中显示它。它在模拟器中完美运行。但是在设备上，来自uiimagepicker的图像被旋转。如何解决这个问题？

Answer 1

由于手机相机的纵向/横向方向，会出现此问题。像

一样重新旋转图像

CGImageRef imageRef = [sourceImage CGImage];

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

或尝试这样的事情

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();
}

Answer 2

在使用之前固定图像的方向。使用以下扩展名可修复UIImage方向。

public void SetMenu()
{
    
    float angle = -180 / (childButtons.Count - 1) * Mathf.Deg2Rad; //-180 is the total degree range our buttons will fill. -1 because we want the distance of the gaps between buttons.

    for (int i = 0; i < childButtons.Count; i++) //For each button...
    {
        float xpos = Mathf.Cos(angle * i) * buttonDistance; //Make coordinates along an angle increment depending on the total number of buttons to...
        float ypos = Mathf.Sin(angle * i) * buttonDistance;

        childButtons[i].transform.localPosition = new Vector3(transform.localPosition.x + xpos, transform.localPosition.y + ypos, transform.localPosition.z); //Place the button
    }

}

用法：

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)
    }
}

来自UIIMagePicker的图像被旋转

2 个答案: