How to Show a Page if Application is Launched for the First Time

Question

I am wondering how to signal whether an appication is launched for the very first time, or has already been launched before. The reason I want to do this is to show a very s

Answer 1

You'd better to use the power of UriMapper

Here you can find a good article.

The core idea is:

You should define an empty page (EntryPage.xaml) and set it as a default page of your app. Then in your custom UriMapper you overload the MapUri method.

   public class YourUriMapper : UriMapperBase
   {
    public override Uri MapUri(Uri uri)
    {
        if (uri.OriginalString == "/EntryPage.xaml")
        {
            var settings = IsolatedStorageSettings.ApplicationSettings;

            if (!settings.Contains("WasLaunched"))
            {
                 uri = new Uri("/FirstRunInfoPage.xaml", UriKind.Relative);
            }
            else
            {
                 uri = new Uri("/MainPage.xaml", UriKind.Relative);
             }
         }
            return uri;
     } 
  }

Then on app initialization you should define which UriMapper to use:

private void Application_Launching(object sender, LaunchingEventArgs e)
{
    RootFrame.UriMapper = new YourUriMapper();
}

private void Application_Activated(object sender, ActivatedEventArgs e)
{
    if (e.IsApplicationInstancePreserved == false)
    {
      // tombstoned! Need to restore state
      RootFrame.UriMapper = new YourUriMapper();
    }
}

Answer 2

The best approach for the check is to write the status in the Isolated storage as you currently are. To redirect to the appropriate page, I would personally use a URI mapper. that way, your first intended entry page would be in the navigation first entry stack, preventing users from navigating back to the first page. A typical use case would be to redirect a user to a an authentication page when a user isn't authenticated and to a home page when the user is already authenticated, see This example

  public App()
    {
        SetUpLandingPageView();
    }


     void SetUpLandingPageView()
    {
        var isLaunched = IsolatedStorageSettings.ApplicationSettings.Contains("WasLaunched");

        // Get the UriMapper from the app.xaml resources, and assign it to the root frame
        var mapper = Resources["mapper"] as UriMapper;

        if (mapper == null) 
            throw new ArgumentNullException("Mapper must be configured");

        RootFrame.UriMapper = Resources["mapper"] as UriMapper;

        // Update the mapper as appropriate
        mapper.UriMappings[0].MappedUri = isLaunched ? new Uri("/Views/HomePage.xaml", UriKind.Relative) : new Uri("/Views/Introduction.xaml", UriKind.Relative);    
    }

In the app.xaml

Namespace:

xmlns:UriMapper="clr-namespace:System.Windows.Navigation;assembly=Microsoft.Phone"

Xaml

 <Application.Resources>
    <ResourceDictionary>
        <UriMapper:UriMapper x:Name="mapper">
            <UriMapper:UriMapping Uri="/MainPage.xaml" />
        </UriMapper:UriMapper>
    </ResourceDictionary>
</Application.Resources>