/// <summary>
/// Called when we have a page to navigated event
/// This event is raised whenever we visit the page. This can occur for the
/// following situations
/// 1) Application Activation where we are tomb stoned, or we are still in memory
/// If we have been tomb stoned, we need to read objects from the application
/// service, and then perform any initialization on the restored objects.
/// If we received and activation event, but we were not tomb stoned, then
/// we actually don't need to do anything except clear the main application
/// state flag and exit. This is because all objects are still in memory.
/// 2) We have come from the main page of the application.
/// To work around a known issue in the Pivot control related to applying templates to
/// non default pivot items we can't set the Pivot Index in this function.
/// We therefore save the desired pivot index and we will set this later
/// </summary>
/// <param name="e">Event data.</param>
protected override void OnNavigatedTo(NavigationEventArgs e)
{
base.OnNavigatedTo(e);
if (ApplicationState.ApplicationStartup == AppOpenState.None &&
this.pivot.Items.Count <= 1)
{
// We have come from the main page of the application
this.viewModel.AllowNavigation = false;
this.PostNavigationToInitialize();
CategorySelectionViewModel.SyncStateToMainPageState();
this.requestedPivotDataSelectionIndex =
CategorySelectionViewModel.GetCategoryPivotIndex(pivot);
}
else
{
// Activated event case
if (!this.IsPageActivated)
{
// We are returning to the application, but we were not tomb stoned.
ApplicationState.ApplicationStartup = AppOpenState.None;
return;
}
this.viewModel.AllowNavigation = false;
ApplicationState.RetrieveAppObjects(true);
this.PostNavigationToInitialize();
this.requestedPivotDataSelectionIndex =
ApplicationState.CategoryPageInformation.PivotSelectedIndex;
if (this.requestedPivotDataSelectionIndex == 0)
{
/* If the index is 0, we don't receive an event for the pivot item
* changing which will cause the pivot to not render correctly.
* We can set the index to 1 ( normal default) without causing any
* problem for the pivot control. We will then set the index to
* 0 later and we should get the event to fire
*/
this.viewModel.SelectedDataIndex = 1;
}
}
// Reenabled buttons
this.viewModel.AllowNavigation = true;
pivot.Opacity = 0;
ApplicationState.ApplicationStartup = AppOpenState.None;
}
