图片旋转

图片旋转

if (image.size.width >= 470.0f) 

    {

UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0,0,image.size.width, image.size.height)];

CGAffineTransform t = CGAffineTransformMakeRotation(M_PI/2);

rotatedViewBox.transform = t;

CGSize rotatedSize = rotatedViewBox.frame.size;

[rotatedViewBox release];

// Create the bitmap context

UIGraphicsBeginImageContext(rotatedSize);

CGContextRef bitmap = UIGraphicsGetCurrentContext();

// Move the origin to the middle of the image so we will rotate and scale around the center.

CGContextTranslateCTM(bitmap, rotatedSize.width/2, rotatedSize.height/2);

//   // Rotate the image context

CGContextRotateCTM(bitmap, M_PI/2);

// Now, draw the rotated/scaled image into the context

CGContextScaleCTM(bitmap, 1.0, -1.0);

CGContextDrawImage(bitmap, CGRectMake(-image.size.width / 2, -image.size.height / 2, image.size.width, image.size.height), [image CGImage]);

UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

self.image = newImage;

        或者//self.image = [self rotateUIImage:image angleDegrees:90.0f];

}

- (UIImage *)rotateUIImage:(UIImage*)src angleDegrees:(float)angleDegrees

{

    UIView* rotatedViewBox = [[UIView alloc] initWithFrame: CGRectMake(0, 0, src.size.width, src.size.height)];

    float angleRadians = angleDegrees * ((float)M_PI / 180.0f);

    CGAffineTransform t = CGAffineTransformMakeRotation(angleRadians);

    rotatedViewBox.transform = t;

    CGSize rotatedSize = rotatedViewBox.frame.size;

    [rotatedViewBox release];

    

    UIGraphicsBeginImageContext(rotatedSize);

    CGContextRef bitmap = UIGraphicsGetCurrentContext();

    CGContextTranslateCTM(bitmap, rotatedSize.width/2, rotatedSize.height/2);

    CGContextRotateCTM(bitmap, angleRadians);

    

    CGContextScaleCTM(bitmap, 1.0, -1.0);

    CGContextDrawImage(bitmap, CGRectMake(-src.size.width / 2, -src.size.height / 2, src.size.width, src.size.height), [src CGImage]);

    

    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    

    return newImage;

}