Navigating Windows Phone 8 Pivot - windows-phone-8

Question

While working on Windows Phone 8 app, we need to restrict user on navigating pivot.
For example, only first two items are available until user make his selection on second item, then third is unlocked, and so on.
I've tried several approaches, and all of them stumble on one thing - setting pivot.SelectedIndex (or pivot.SelectedItem) inside event handler does not changing visual representation of pivot.
What is missing in my approach?
Here is sample code, from one of variants I've tried...
private void ReservationPivot_UnloadingPivotItem(object sender, PivotItemEventArgs e)
{
if (previousSelectedIndex != ((Pivot)sender).Items.IndexOf(e.Item) && !pivotRedirect)
previousSelectedIndex = ((Pivot)sender).Items.IndexOf(e.Item);
else if (previousSelectedIndex == ((Pivot)sender).Items.IndexOf(e.Item))
return;
object tmp;
PhoneApplicationService.Current.State.TryGetValue("PickupAddress", out tmp);
if (e.Item == ((Pivot)sender).Items[1] && tmp == null && !pivotRedirect)
{
MessageBox.Show("Please, select pickup point!");
pivotRedirect = true;
((Pivot)sender).SelectedIndex = previousSelectedIndex;
((Pivot)sender).SelectedItem = ((Pivot)sender).Items[1];
return;
}
PhoneApplicationService.Current.State.TryGetValue("DropOffAddress", out tmp);
if (e.Item == ((Pivot)sender).Items[2] && tmp == null && !pivotRedirect)
{
MessageBox.Show("Please, select dropoff point!");
pivotRedirect = true;
((Pivot)sender).SelectedIndex = previousSelectedIndex;
((Pivot)sender).SelectedItem = ((Pivot)sender).Items[2];
return;
}
if (pivotRedirect)
{
if (((Pivot)sender).SelectedIndex != previousSelectedIndex)
{
pivotRedirect = false;
((Pivot)sender).SelectedIndex = previousSelectedIndex;
}
}
}

Answer 1

Dont have access to visual now but did you try set visible of third pivot item to collapsed and change it to visible when user will select dropooff point ?