public ItemPage()
        {
            this.InitializeComponent();

            this.navigationHelper = new NavigationHelper(this);
            this.navigationHelper.LoadState += this.NavigationHelper_LoadState;
            this.navigationHelper.SaveState += this.NavigationHelper_SaveState;
        } 
 public ElegirTienda()
 {
     this.InitializeComponent();
     
     this.navigationHelper = new NavigationHelper(this);
     this.navigationHelper.LoadState += this.NavigationHelper_LoadState;
     this.navigationHelper.SaveState += this.NavigationHelper_SaveState;
 }
        public PivotPage()
        {
            this.InitializeComponent();

            this.NavigationCacheMode = NavigationCacheMode.Required;

            this.navigationHelper = new NavigationHelper(this);
            this.navigationHelper.LoadState += this.NavigationHelper_LoadState;
            this.navigationHelper.SaveState += this.NavigationHelper_SaveState;
        }
        public HubPage()
        {
            this.InitializeComponent();

            // Hub is only supported in Portrait orientation
            DisplayInformation.AutoRotationPreferences = DisplayOrientations.Portrait;

            this.NavigationCacheMode = NavigationCacheMode.Required;
            Hub.Header = "Mobile Center";
            this.navigationHelper = new NavigationHelper(this);
            this.navigationHelper.LoadState += this.NavigationHelper_LoadState;
            this.navigationHelper.SaveState += this.NavigationHelper_SaveState;
        }