public void Scan(IOverlaySettings overlaySettings)
{
this.overlaySettings = overlaySettings;
var window = UIApplication.SharedApplication.KeyWindow;
var vc = window.RootViewController;
recognizerRunnerViewController = MBViewControllerFactory.RecognizerRunnerViewControllerWithOverlayViewController(((OverlaySettings)overlaySettings).CreateOverlayViewController(this));
vc.PresentViewController(ObjCRuntime.Runtime.GetINativeObject <UIViewController>(recognizerRunnerViewController.Handle, false), true, null);
}