public class NavigationService
	{
		/// <summary>
		/// This holds the instance to the Only NavigationService in this app.
		/// </summary>
		public static NavigationService Instance { get; protected set; }

        public static NavigationService NavServiceArea { get; protected set; }

        /// <summary>
        /// This will hold the reference to the frame that is to be manipulated.
        /// </summary>
        private Frame frame;

		/// <summary>
		/// The Stack of pages to enable Stack based Navigation.
		/// </summary>
		public Stack<Type> PageStack { get; protected set; }

		#region CTOR
		/// <summary>
		/// The default constructor to instantiate this class with reference to a frame
		/// </summary>
		/// <param name="frame">The referenced frame</param>
		public NavigationService( ref Frame frame )
		{
			//Check is the instance doesnt already exist.
			if (Instance != null)
			{
				//if there is an instance in the app already present then simply throw an error.
				throw new Exception("Only one navigation service can exist in a App.");
			}
			//setting the instance to the static instance field.
			Instance = this;
			//setting the frame reference.
			this.frame = frame;

         //   frame.DataContext = frame_datacontext;

			//intialising the stack.
			this.PageStack = new Stack<Type>();

			//Hooking up the events for BackRequest both for Big Windows and for Phone.

			SystemNavigationManager.GetForCurrentView().BackRequested += NavigationService_BackRequested;
        }

        #endregion


        #region Navigation Methods

        public  void NavigateTo(Type pageType, object parameter)
        {        
            if (PageStack.Count > 0)
            {
                if (PageStack.Peek() == pageType)
                 return;
            }

            PageStack.Push(pageType);
            frame.Navigate(pageType, parameter);
            UpdateBackButtonVisibility();

        }

        public void NavigateBack()
		{
			if (frame.CanGoBack)
				frame.GoBack();
			PageStack.Pop();
			UpdateBackButtonVisibility();
		}

		public void NavigateToHome()
		{
			while (frame.CanGoBack)
				frame.GoBack();
		}
		#endregion


		#region BackButtonVisibilty Region
		void UpdateBackButtonVisibility()
		{
			SystemNavigationManager.GetForCurrentView().AppViewBackButtonVisibility = frame.CanGoBack ?
		    AppViewBackButtonVisibility.Visible : AppViewBackButtonVisibility.Collapsed;
		}
		#endregion

		#region Event Methods for windows and phone

		private void NavigationService_BackRequested( object sender , BackRequestedEventArgs e )
		{
			this.NavigateBack();
		}

		#endregion

	}

  sealed partial class App : Application
    {
        public static NavigationService NavService { get; protected set;}

      

        /// <summary>
        /// Инициализирует одноэлементный объект приложения.  Это первая выполняемая строка разрабатываемого
        /// кода; поэтому она является логическим эквивалентом main() или WinMain().
        /// </summary>
        public App()
        {
            this.InitializeComponent();
            this.Suspending += OnSuspending;
        }

        /// <summary>
        /// Вызывается при обычном запуске приложения пользователем.  Будут использоваться другие точки входа,
        /// например, если приложение запускается для открытия конкретного файла.
        /// </summary>
        /// <param name="e">Сведения о запросе и обработке запуска.</param>
        protected override void OnLaunched(LaunchActivatedEventArgs e)
        {
#if DEBUG
            if (System.Diagnostics.Debugger.IsAttached)
            {
                //this.DebugSettings.EnableFrameRateCounter = true;
            }
#endif

            MainPageUserControl mnpage = Window.Current.Content as MainPageUserControl;       

            // Do not repeat app initialization when the Window already has content,
            // just ensure that the window is active
            if (mnpage == null)
            {
                // Create a Frame to act as the navigation context and navigate to the first page
                mnpage = new MainPageUserControl();

                if (mnpage.rootFrame == null) mnpage.rootFrame = new Frame();

                NavService = new NavigationService(ref mnpage.rootFrame);

                mnpage.rootFrame.NavigationFailed += OnNavigationFailed;

                if (e.PreviousExecutionState == ApplicationExecutionState.Terminated)
                {
                    //TODO: Load state from previously suspended application
                }
            }
            // Place the frame in the current Window
            Window.Current.Content = mnpage;
            // Ensure the current window is active
            Window.Current.Activate();

            if (mnpage.rootFrame.Content == null)
            {
                // When the navigation stack isn't restored navigate to the first page,
                // configuring the new page by passing required information as a navigation
                // parameter
                NavService.NavigateTo(typeof(passwordpage), null);
            }
        }

        /// <summary>
        /// Вызывается в случае сбоя навигации на определенную страницу
        /// </summary>
        /// <param name="sender">Фрейм, для которого произошел сбой навигации</param>
        /// <param name="e">Сведения о сбое навигации</param>
        void OnNavigationFailed(object sender, NavigationFailedEventArgs e)
        {
            throw new Exception("Failed to load Page " + e.SourcePageType.FullName);
        }

        /// <summary>
        /// Вызывается при приостановке выполнения приложения.  Состояние приложения сохраняется
        /// без учета информации о том, будет ли оно завершено или возобновлено с неизменным
        /// содержимым памяти.
        /// </summary>
        /// <param name="sender">Источник запроса приостановки.</param>
        /// <param name="e">Сведения о запросе приостановки.</param>
        private void OnSuspending(object sender, SuspendingEventArgs e)
        {
            var deferral = e.SuspendingOperation.GetDeferral();
            //TODO: Сохранить состояние приложения и остановить все фоновые операции
            deferral.Complete();
        }
    }

<UserControl
    x:Class="MyFirstUWPApp.View.MainPageUserControl"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:MyFirstUWPApp.View"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    d:DesignHeight="300"
    d:DesignWidth="400">

    <Frame Grid.Row="1"
				 x:Name="rootFrame"
				 x:FieldModifier="public">
    </Frame>
    
</UserControl>

<VM:BasePage
    x:Class="MyFirstUWPApp.View.MainAppPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:MyFirstUWPApp.View"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:VM="using:MyFirstUWPApp.ViewModel"
    NavigationCacheMode="Enabled" 
    mc:Ignorable="d">

    <VM:BasePage.DataContext >
        <VM:MainAppPageViewModel />
    </VM:BasePage.DataContext>

    <SplitView DisplayMode="CompactInline"
               IsPaneOpen="{Binding IsPaneOpen, UpdateSourceTrigger=PropertyChanged}" 
               CompactPaneLength="50" OpenPaneLength="200">

        <SplitView.Pane>
            <StackPanel Orientation="Vertical">

                <StackPanel Orientation="Horizontal">
                    <Button x:Name="MenuButton1" FontFamily="Segoe MDL2 Assets" Content="&#xE700;"
                    Width="50" Height="50" Background="Transparent"
                    Tapped="{x:Bind ViewModel.hide_command}" />
                </StackPanel>
               
                <StackPanel Orientation="Horizontal">
                
                <Button  FontFamily="Times New Roma" Content="S"                            
                 Width="50" Height="50" Background="Transparent"
                 Tapped="{x:Bind ViewModel.show_sprav_menu}"/>

                <Button  FontFamily="Times New Roma" Content="Справочник"                            
                 Width="150" Height="50" Background="Transparent"
                 Tapped="{x:Bind ViewModel.show_sprav_menu}"/>
                </StackPanel>
                
            </StackPanel>
        </SplitView.Pane>


        <SplitView.Content>

            <Frame Grid.Row="1"
				 x:Name="FrameArea"
				 x:FieldModifier="public">
            </Frame>
            
        </SplitView.Content>
        
    </SplitView>
    
</VM:BasePage>

 BasePage  p = (MainAppPage)pageType;