Capture an image of a view not yet displayed

// Capture an image of a view, inside of a ViewController with Xib, not yet displayed.
// use:
// CaptureViewController *viewController = [[CaptureViewController alloc] initWithNibName:@"CaptureViewController" bundle:nil];
// [viewController loadView];
// UIImage *img = [viewController capture];
//
- (UIImage*)capture {

    UIGraphicsBeginImageContext(self.view.bounds.size);
    CGContextRef context = UIGraphicsGetCurrentContext();

    [self.view.layer renderInContext:context];

    UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return img;
}