private void OnSelectIndexMessage(SelectIndexMessage message)
{
if (message.TypeContext == typeof(MainPageViewModel))
{
if (message.Index < pivot.Items.Count && message.Index >= 0)
{
pivot.SelectedIndex = message.Index;
}
else if (message.Index == -1)
{
pivot.SelectedIndex = pivot.Items.Count - 1;
}
}
}
