How can I make a good splash screen that does two actions at once?

Question

I'm currently trying to make a splash screen, however, I can't seem to be able to make a few tasks setup things at once.

I've tried using the BackgroundWorker class, as well as the Thread class, and none seem to work.

In the App.xaml.cs:

protected override void OnStartup(StartupEventArgs e)
{
    var splashScreen = new Windows.Splash();
    splashScreen.Show();

    base.OnStartup(e);

    splashScreen.Close();
}

In the splashScreen.xaml.cs:

public Splash()
{
    InitializeComponent();
    DataContext = this;

    changeLoadingTxtTimer = new System.Timers.Timer(2000);
    changeLoadingTxtTimer.Elapsed += Timer_Elapsed;

    backgroundWorker = new BackgroundWorker();
    backgroundWorker.DoWork += D_DoWork;
    backgroundWorker.RunWorkerAsync();

    changeLoadingTxtTimer.Start();
}

private void D_DoWork(object sender, DoWorkEventArgs e) { UpdateDatabase(); }

private void Timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
{
    LoadingTxtValue = LoadingTxts[rd.Next(0, LoadingTxts.Length - 1)];

    if (!backgroundWorker.IsBusy)
        changeLoadingTxtTimer.Stop();
    }
}

I expect that as the BackgroundWorker works, the loading text will change every 2 seconds, but what actually happens is that the BackgroundWorker finishes its job, and the splash screen closes.

Answer 1

App.xaml

Remove the StartupUri entry

<Application
      x:Class="WpfSplashApp.App"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      xmlns:local="clr-namespace:WpfSplashApp">
    <Application.Resources />
</Application>

App.xaml.cs

public partial class App : Application
{
    public App()
    {
        Startup += App_Startup;
    }

    private async void App_Startup( object sender, StartupEventArgs e )
    {
        var splash = new SplashWindow();
        splash.Show();

        await InitializeAsync();

        var main = new MainWindow();
        main.Show();
        MainWindow = main;

        splash.Close();            
    }

    private Task InitializeAsync()
    {
        // Do some ASYNC initialization 
        return Task.Delay( 5000 );
    }
}