screenshots use drawViewHierarchyInRect blocking mainthread

I use this mehtod for screenshots，but it blocking mainthread, Is there another way to replace it ，

{
UIGraphicsBeginImageContextWithOptions(imageSize, NO, 0);
  CGContextRef context = UIGraphicsGetCurrentContext();

  for (UIWindow *window in [[UIApplication sharedApplication] windows]) {
    CGContextSaveGState(context);
    CGContextTranslateCTM(context, window.center.x, window.center.y);
    CGContextConcatCTM(context, window.transform);
    CGContextTranslateCTM(context, -window.bounds.size.width * window.layer.anchorPoint.x,
               -window.bounds.size.height * window.layer.anchorPoint.y);
    if ([window respondsToSelector:@selector(drawViewHierarchyInRect:afterScreenUpdates:)]) {
      [window drawViewHierarchyInRect:window.bounds afterScreenUpdates:YES];
    } else {
      [window.layer renderInContext:context];
    }
    CGContextRestoreGState(context);
  }
  UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
  UIGraphicsEndImageContext();
}

Is there an alternative way to take screenshots

I need your help