How to rotate UIImage

Question

I\'m developing an iOS app for iPad. Is there any way to rotate a UIImage 90º and then add it to a UIImageView? I\'ve tried a lot of different codes but none worked...

Answer 1

To rotate the pixels you can use the following. This creates an intermediate UIImage with rotated metadata and renders it into a image context with width/height dimensions transposed. The resulting image has the pixels rotated (i.e the underlying CGImage)

- (UIImage*)rotateUIImage:(UIImage*)sourceImage clockwise:(BOOL)clockwise
{
    CGSize size = sourceImage.size;
    UIGraphicsBeginImageContext(CGSizeMake(size.height, size.width));
    [[UIImage imageWithCGImage:[sourceImage CGImage] scale:1.0 orientation:clockwise ? UIImageOrientationRight : UIImageOrientationLeft] drawInRect:CGRectMake(0,0,size.height ,size.width)];
    UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return newImage;
}

There are other possible values that can be passed for the orientation parameter to achieve 180 degree rotation and flips etc.