UIApplication.SharedApplication.Windows[0].RootViewController return null in Initialize() method


I have monogame Version nuget package in xamarin studio, in the initialize() method of may game, i try to get root viewcontroler like this:

var controller = UIApplication.SharedApplication.Windows[0].RootViewController;

but return null , RootViewController is null :frowning:

¿Is a bug?
¿Other way to get RootViewController?

Please help.

Thanks in advance, and sorry for my english.

I found the solution in http://www.nogginbox.co.uk/blog/iAds-in-MonoGame, thanks to NogginBox