Catel.Services.NavigationService.GetBackStackCount C# (CSharp) Метод

        public override int GetBackStackCount()
        {
#if NETFX_CORE
            return RootFrame.BackStackDepth;
#elif WINDOWS_PHONE
            return RootFrame.BackStack.Cast<object>().Count();
#elif SILVERLIGHT
            throw new NotSupportedInPlatformException();
#else
            return RootFrame.BackStack.Cast<object>().Count();
#endif
        }