旋转 UIImage 或 UIImageView 自定义度数答案

【问题标题】：Rotate UIImage or UIImageView custom degree旋转 UIImage 或 UIImageView 自定义度数
【发布时间】：2012-04-18 10:19:14
【问题描述】：

我想旋转 UIImage 或 UIImageView，我尝试了很多代码，到处搜索，但我找不到有效的解决方案，我正在解释问题，我从网上下载了一张图片，然后我用这种方式调整它的大小：

- (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;
}

并且调整大小工作得很好，然后我已将我的 UIImage 附加到我的 UIImageView 上，然后我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锯齿，所以我尝试先旋转 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

通过这种方式，边框被抗锯齿，反而损失了图像质量，它更模糊，而且不像第一次旋转它那样锐利，有人有好的解决方案吗？

谢谢...

【问题讨论】：

标签： ios uiimageview uiimage image-rotation

【解决方案1】：

用于旋转图像..您可以使用此 IBAction ...每次单击按钮，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，您只需为以下方法传递 UIimage 和旋转度数

- (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.......！通过单击Objective C中的按钮来旋转原始图像

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

【讨论】：