iOS拍照后图片自动旋转90度的完美解决方法

+ (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) {    caseUIImageOrientationDown:    caseUIImageOrientationDownMirrored:      transform = CGAffineTransformTranslate(transform, aImage.size.width, aImage.size.height);      transform = CGAffineTransformRotate(transform, M_PI);      break;    caseUIImageOrientationLeft:    caseUIImageOrientationLeftMirrored:      transform = CGAffineTransformTranslate(transform, aImage.size.width,0);      transform = CGAffineTransformRotate(transform, M_PI_2);      break;    caseUIImageOrientationRight:    caseUIImageOrientationRightMirrored:      transform = CGAffineTransformTranslate(transform, 0, aImage.size.height);      transform = CGAffineTransformRotate(transform, -M_PI_2);      break;    default:      break;  }  switch (aImage.imageOrientation) {    caseUIImageOrientationUpMirrored:    caseUIImageOrientationDownMirrored:      transform = CGAffineTransformTranslate(transform, aImage.size.width,0);      transform = CGAffineTransformScale(transform, -1, 1);      break;    caseUIImageOrientationLeftMirrored:    caseUIImageOrientationRightMirrored:      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) {    caseUIImageOrientationLeft:    caseUIImageOrientationLeftMirrored:    caseUIImageOrientationRight:    caseUIImageOrientationRightMirrored:      // 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 = [UIImageimageWithCGImage:cgimg];  CGContextRelease(ctx);  CGImageRelease(cgimg);  return img;}