iOS编辑图片后图片旋转

直接粘贴就可以使用

注意:需要在处理图片之前 调用此方法

//处理图片因为图像转换而旋转
- (UIImage *)fixOrientation:(UIImage *)aImage {
   
   // No-op if the orientation is already correct
   if (aImage.imageOrientation == UIImageOrientationUp)
       return aImage;
   
   // We need to calculate the proper transformation to make the image upright.
   // We do it in 2 steps: Rotate if Left/Right/Down, and then flip if Mirrored.
   CGAffineTransform transform = CGAffineTransformIdentity;
   
   switch (aImage.imageOrientation) {
       case UIImageOrientationDown:
       case UIImageOrientationDownMirrored:
           transform = CGAffineTransformTranslate(transform, aImage.size.width, aImage.size.height);
           transform = CGAffineTransformRotate(transform, M_PI);
           break;
           
       case UIImageOrientationLeft:
       case UIImageOrientationLeftMirrored:
           transform = CGAffineTransformTranslate(transform, aImage.size.width, 0);
           transform = CGAffineTransformRotate(transform, M_PI_2);
           break;
           
       case UIImageOrientationRight:
       case UIImageOrientationRightMirrored:
           transform = CGAffineTransformTranslate(transform, 0, aImage.size.height);
           transform = CGAffineTransformRotate(transform, -M_PI_2);
           break;
       default:
           break;
   }
   
   switch (aImage.imageOrientation) {
       case UIImageOrientationUpMirrored:
       case UIImageOrientationDownMirrored:
           transform = CGAffineTransformTranslate(transform, aImage.size.width, 0);
           transform = CGAffineTransformScale(transform, -1, 1);
           break;
           
       case UIImageOrientationLeftMirrored:
       case UIImageOrientationRightMirrored:
           transform = CGAffineTransformTranslate(transform, aImage.size.height, 0);
           transform = CGAffineTransformScale(transform, -1, 1);
           break;
       default:
           break;
   }
   
   // Now we draw the underlying CGImage into a new context, applying the transform
   // calculated above.
   CGContextRef ctx = CGBitmapContextCreate(NULL, aImage.size.width, aImage.size.height,
                                            CGImageGetBitsPerComponent(aImage.CGImage), 0,
                                            CGImageGetColorSpace(aImage.CGImage),
                                            CGImageGetBitmapInfo(aImage.CGImage));
   CGContextConcatCTM(ctx, transform);
   switch (aImage.imageOrientation) {
       case UIImageOrientationLeft:
       case UIImageOrientationLeftMirrored:
       case UIImageOrientationRight:
       case UIImageOrientationRightMirrored:
           // Grr...
           CGContextDrawImage(ctx, CGRectMake(0,0,aImage.size.height,aImage.size.width), aImage.CGImage);
           break;
           
       default:
           CGContextDrawImage(ctx, CGRectMake(0,0,aImage.size.width,aImage.size.height), aImage.CGImage);
           break;
   }
   
   // And now we just create a new UIImage from the drawing context
   CGImageRef cgimg = CGBitmapContextCreateImage(ctx);
   UIImage *img = [UIImage imageWithCGImage:cgimg];
   CGContextRelease(ctx);
   CGImageRelease(cgimg);
   return img;
}