Heres the solution to it But I guess you need to share more about the problem if this doesnot help
<Storyboard x:Name="StoryboardTest" Completed="Storyboard_Completed">
//What ever animation you want to do
</Storyboard>
And in the cs file:
private void Storyboard_Completed(object sender, EventArgs e)
{
NavigationService.Navigate(new Uri("/SecondPage.xaml", UriKind.Relative));
}
For a demo on animating splash screen go to this link progress bar splash screen and apply your animation accordingly.