Question

我想要旋转UIImage或UIImageView，我已经尝试了很多代码，并且到处搜索，但我找不到有效的解决方案，我解释问题，我从网上下载图像然后我以这种方式调整大小：

- (UIImage *)imageWithImage:(UIImage *)image scaledToSize:(CGSize)newSize {
//UIGraphicsBeginImageContext(newSize);
UIGraphicsBeginImageContextWithOptions(newSize, NO, 0.0);
[image drawInRect:CGRectMake(0, 0, newSize.width, newSize.height)];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();    
UIGraphicsEndImageContext();
return newImage;
}

然后调整大小非常好我已将UIImage附加到我的UIImageView上，然后以这种方式旋转我的UIImageView：

self.myImageView.transform = CGAffineTransformMakeRotation(degreesToRadian(-2));

但是这样边框是像素化的并且有别名，所以我试图首先旋转UIImage，然后将图像提供给我的UIImageView，我发现了很多类似的代码，特别是我使用这个类扩展：

http://www.catamount.com/forums/viewtopic.php?f=21&t=967

并且通过这种方式，边框是防褪色的，但是图像质量损失，它更模糊，并且不像旋转它那样尖锐，任何人都有一个很好的解决方案？

感谢...

Answer 1

对于旋转图像..你可以使用这个IBAction ...对于每一个按钮点击，图像将旋转90度......

-(IBAction)rotateImageClick:(id)sender{

UIImage *image2=[[UIImage alloc]init];
image2 = [self imageRotatedByDegrees:self.roateImageView.image deg:(90)]; //Angle by 90 degree
self.roateImageView.image = image2;
imgData= UIImageJPEGRepresentation(image2,0.9f);

}

对于旋转图像，您只需要传递UIimage和旋转度数以获得以下方法

- (UIImage *)imageRotatedByDegrees:(UIImage*)oldImage deg:(CGFloat)degrees

// --------------------------------------------- ---------------------------

#pragma mark - imageRotatedByDegrees Method

- (UIImage *)imageRotatedByDegrees:(UIImage*)oldImage deg:(CGFloat)degrees{

    // calculate the size of the rotated view's containing box for our drawing space
    UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0,0,oldImage.size.width, oldImage.size.height)];

    CGAffineTransform t = CGAffineTransformMakeRotation(degrees * M_PI / 180);
    rotatedViewBox.transform = t;

    CGSize rotatedSize = rotatedViewBox.frame.size;
    // 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, (degrees * M_PI / 180));

    // Now, draw the rotated/scaled image into the context
    CGContextScaleCTM(bitmap, 1.0, -1.0);
    CGContextDrawImage(bitmap, CGRectMake(-oldImage.size.width / 2, -oldImage.size.height / 2, oldImage.size.width, oldImage.size.height), [oldImage CGImage]);

    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return newImage;

}

我认为这个链接会有所帮助.......！单击Objective C

中的按钮旋转原始图像

http://adrianmobileapplication.blogspot.com/2015/03/rotate-original-image-by-clicking.html

旋转UIImage或UIImageView自定义度

1 个答案: