ios - IOS 中的图像旋转

Question

当我将相机图像转换为 base64 时，我正在使用 Xcode 7.3 和 ojective-c 我的应用程序之一，然后图像将旋转向左 90 度我尝试了很多方法来解决这个问题，但没有一个奏效。

Below are the code:

NSString *data64URLString = [NSString stringWithFormat:@"data:image/png;base64,%@", [UIImageJPEGRepresentation(image, 0) base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength]];

我通过这种方式尝试了所有方向，但它不起作用:

CGImageRef cgRef = image.CGImage;
   image = [[UIImage alloc] initWithCGImage:cgRef scale:1.0 orientation:UIImageOrientationDownMirrored];
    UIImage *originalImage = image;

Answer 1

试试这段代码:

  -  (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;
   }