Class used to hold the event data required when a page attempts to load state.
상속: System.EventArgs
 /// <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>
 private void navigationHelper_LoadState(object sender, LoadStateEventArgs 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>
        private void navigationHelper_LoadState(object sender, LoadStateEventArgs e)
        {
            // TODO: Assign a bindable group to Me.DefaultViewModel("Group")
            // TODO: Assign a collection of bindable items to Me.DefaultViewModel("Items")

            if (e.PageState == null)
            {
                // When this is a new page, select the first item automatically unless logical page
                // navigation is being used (see the logical page navigation #region below.)
                if (!this.UsingLogicalPageNavigation() && this.itemsViewSource.View != null)
                {
                    this.itemsViewSource.View.MoveCurrentToFirst();
                }
            }
            else
            {
                // Restore the previously saved state associated with this page
                if (e.PageState.ContainsKey("SelectedItem") && this.itemsViewSource.View != null)
                {
                    // TODO: Invoke Me.itemsViewSource.View.MoveCurrentTo() with the selected
                    //       item as specified by the value of pageState("SelectedItem")

                }
            }
        }