protected override void LoadState(object sender, LoadStateEventArgs e)
        {
            if (e.PageState != null)
            {
                if (e.PageState.ContainsKey(PageValues.SELECTED_PIVOT_INDEX))
                    pivot.SelectedIndex = (int)e.PageState[PageValues.SELECTED_PIVOT_INDEX];
            }

        }
        protected override void LoadState(object sender, LoadStateEventArgs e)
        {
            if (e.PageState == null) return;

            if (e.PageState.ContainsKey("position"))
            {
                _visibleIndex = (int)e.PageState["position"];
                //ScrollToIndex(_visibleIndex);
            }

            base.LoadState(sender, e);
        }
 /// <summary>
 /// Populates the page with content passed during navigation.  Any saved state is also
 /// provided when recreating a page from a prior session.
 /// </summary>
 /// <param name="sender">
 /// The source of the event; typically <see cref="NavigationHelper"/>
 /// </param>
 /// <param name="e">Event data that provides both the navigation parameter passed to
 /// <see cref="Frame.Navigate(Type, Object)"/> when this page was initially requested and
 /// a dictionary of state preserved by this page during an earlier
 /// session.  The state will be null the first time a page is visited.</param>
 protected virtual void LoadState(object sender, LoadStateEventArgs e)
 {
 }