帮助,我是ios编程的新手,我想旋转可能UIImage但我不希望边缘被切割或松散图像的某些部分.
这是我的代码:
double angle = M_PI * 10/ 180; CGSize s = {image.size.width, image.size.height}; UIGraphicsBeginImageContext(s); CGContextRef ctx = UIGraphicsGetCurrentContext(); CGAffineTransform transform = CGAffineTransformIdentity; transform = CGAffineTransformTranslate(transform, image.size.width/2, image.size.height/2); transform = CGAffineTransformRotate(transform, angle); transform = CGAffineTransformScale(transform, 1.0, -1.0); CGContextConcatCTM(ctx, transform); CGContextDrawImage(ctx,CGRectMake(-[image size].width/2,-[image size].height/2,image.size.width, image.size.height),image.CGImage); UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); UIImageWriteToSavedPhotosAlbum(newImage, nil, nil, nil);
图像正在旋转,但框架的大小不会因为某些图像被切割而改变.
输出:https://fbcdn-sphotos-ea.akamaihd.net/hphotos-ak-xpf1/t1.0-9/1555286_761679470521535_1800180000235265553_n.jpg
预期产出:https://fbcdn-photos-ga.akamaihd.net/hphotos-ak-xfa1/t1.0-0/10314770_761675840521898_6536715783383115855_a.jpg
请帮我谢谢.
这可能就是您要搜索的内容.
只需将以下代码复制到要旋转图像的.m
文件末尾(之后@end
)即可.
@interface UIImage (RotationMethods) - (UIImage *)imageRotatedByDegrees:(CGFloat)degrees; @end @implementation UIImage (RotationMethods) static CGFloat DegreesToRadians(CGFloat degrees) {return degrees * M_PI / 180;}; - (UIImage *)imageRotatedByDegrees:(CGFloat)degrees { // calculate the size of the rotated view's containing box for our drawing space UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0,0,self.size.width, self.size.height)]; CGAffineTransform t = CGAffineTransformMakeRotation(DegreesToRadians(degrees)); 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, DegreesToRadians(degrees)); // Now, draw the rotated/scaled image into the context CGContextScaleCTM(bitmap, 1.0, -1.0); CGContextDrawImage(bitmap, CGRectMake(-self.size.width / 2, -self.size.height / 2, self.size.width, self.size.height), [self CGImage]); UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); return newImage; }
然后旋转图像,如下例所示:
CGFloat degrees = 90; yourImage = [yourImage imageRotatedByDegrees:degrees];