Remove ActionBar from NavigationPage

I want to remove the ActionBar from all the application when using NavigationPage or other "pages".

Tried to remove it from the MainActivity in the OnCreate method like this:

protected override void OnCreate (Bundle bundle)
        {
            base.OnCreate (bundle);


            Xamarin.Forms.Forms.Init (this, bundle);

            SetPage (App.GetLoginPage ());

            // HACK force hiding actionbar
            ActionBar.Hide ();
        }

But it doesn't work..

I have two questions:

1) How can i completely remove the ActionBar from all the application?

2) If i cannot be hidden, then can i add buttons, style and manage the actionbar from Xamarin.Forms? I mean, to manage the ActionBar from my .xaml.cs code.

Thanks!