Question

是否可以在UIImageView中仅旋转图像？我正在寻找有关它的信息，但我只找到了旋转UIImageVeiw的信息。

Answer 1

您可以使用以下代码旋转图像。注意，这使用了CGImageRef，您可以通过

从UIImage获取

CGImageRef imageRef = [self CGImageRotatedByAngle:[image CGImage] angle:30];

获得旋转的图像后，您可以将ImageView的图像设置为新的旋转图像，如下所示：

UIImage* img = [UIImage imageWithCGImage: imageRef];
myImageView.image = img;

这是一个旋转imageRef：

的方法

- (CGImageRef)CGImageRotatedByAngle:(CGImageRef)imgRef angle:(CGFloat)angle
{

    CGFloat angleInRadians = angle * (M_PI / 180);
    CGFloat width = CGImageGetWidth(imgRef);
    CGFloat height = CGImageGetHeight(imgRef);

    CGRect imgRect = CGRectMake(0, 0, width, height);
    CGAffineTransform transform = CGAffineTransformMakeRotation(angleInRadians);
    CGRect rotatedRect = CGRectApplyAffineTransform(imgRect, transform);

    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();

    CGContextRef bmContext = CGBitmapContextCreate(NULL,
                                                   rotatedRect.size.width,
                                                   rotatedRect.size.height,
                                                   8,
                                                   0,
                                                   colorSpace,
                                                   kCGImageAlphaPremultipliedFirst);
    CGContextSetAllowsAntialiasing(bmContext, YES);
    CGContextSetShouldAntialias(bmContext, YES);
    CGContextSetInterpolationQuality(bmContext, kCGInterpolationHigh);
    CGColorSpaceRelease(colorSpace);
    CGContextTranslateCTM(bmContext,
                          +(rotatedRect.size.width/2),
                          +(rotatedRect.size.height/2));
    CGContextRotateCTM(bmContext, angleInRadians);
    CGContextTranslateCTM(bmContext,
                          -(rotatedRect.size.width/2),
                          -(rotatedRect.size.height/2));
    CGContextDrawImage(bmContext, CGRectMake(0, 0,
                                             rotatedRect.size.width,
                                             rotatedRect.size.height),
                       imgRef);



    CGImageRef rotatedImage = CGBitmapContextCreateImage(bmContext);
    CFRelease(bmContext);
    [(id)rotatedImage autorelease];

    return rotatedImage;
}

Answer 2

看看旋转ImageView的图层。您需要导入QuartzCore库才能使其可访问。

myImageView.layer.transform = CGAffineTransformMakeRotation (1.5);

Answer 3

请试试这个，它对我有用：

[UIView beginAnimations:nil context:nil];
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView setAnimationCurve:UIViewAnimationCurveEaseIn];
[UIView setAnimationRepeatCount:10];
myImgView.transform = CGAffineTransformMakeRotation(M_PI);
[UIView commitAnimations];

祝你好运！

Answer 4

以下代码适用于Swift：

let img = UIImage(CGImage: self.imageView.image!.CGImage, scale: 1.0, orientation: UIImageOrientation.Right)
self.imageView.image = img
self.imageView.setNeedsLayout()

Answer 5

如果您需要旋转/翻转图像以进行本地化，可以使用以下内容： imageView.image = imageView.image?.imageFlippedForRightToLeftLayoutDirection()

在UIImageView中旋转图像

5 个答案: