Splash Screen

WinUIEx provides two kinds of splash screens:

• SimpleSplashScreen: A simple splash screen that shows just an image and can be launched before any UI loads.
• SplashScreen: A more advanced splash screen that can show any XAML including a progress bar and status text.

SimpleSplashScreen

SimpleSplashScreen will show an image while the app is loading. To use it, create a new SimpleSplashScreen in App.xaml.cs:

private SimpleSplashScreen fss { get; set; }

public App()
{
  fss = SimpleSplashScreen.ShowDefaultSplashScreen(); // Shows the splash screen you already defined in your app manifest. For unpackaged apps use .ShowSplashScreenImage(imagepath):
  // fss = SimpleSplashScreen.ShowSplashScreenImage(full_path_to_image_); // Shows a custom splash screen image. Must be a full-path (no relative paths)
  this.InitializeComponent();
}

Once your window is activated, you can remove the splash screen by either calling .Dispose() or Hide().

protected override void OnLaunched(Microsoft.UI.Xaml.LaunchActivatedEventArgs args)
{
  m_window = new MainWindow();
  m_window.Activate();
  Window_Activated += Window_Activated;

}

private void Window_Activated(object sender, WindowActivatedEventArgs args)
{
  ((Window)sender).Activated -= Window_Activated;
  fss?.Hide();
  fss = null;
}

For even faster splash screen, disable the XAML generated main method by defining the DISABLE_XAML_GENERATED_MAIN preprocessor directive and instead defining your own start method. You'll then be able to display the splash screen as the very first thing before the application is created. For example:

#if DISABLE_XAML_GENERATED_MAIN
  public static class Program
  {
    [System.STAThreadAttribute]
    static void Main(string[] args)
    {
      // If you're using the WebAuthenticator, make sure you call this method first before the splashscreen shows
      if (WebAuthenticator.CheckOAuthRedirectionActivation(true))
        return;
      var fss = SimpleSplashScreen.ShowDefaultSplashScreen();
      WinRT.ComWrappersSupport.InitializeComWrappers();
      Microsoft.UI.Xaml.Application.Start((p) => {
        var context = new Microsoft.UI.Dispatching.DispatcherQueueSynchronizationContext(Microsoft.UI.Dispatching.DispatcherQueue.GetForCurrentThread());
        System.Threading.SynchronizationContext.SetSynchronizationContext(context);
        new App(fss); // Pass the splash screen to your app so it can close it on activation
      });
    }
  }
#endif

SplashScreen

To create a new splash screen, first create a new WinUI Window. Next change the baseclass from Window to SplashScreen:

Before:

<Window ...>
</Window>

After:

<winuiex:SplashScreen
    xmlns:winuiex="using:WinUIEx" ...>

</winuiex:SplashScreen>

And codebehind:

Before:

public sealed partial class SplashScreen : Window
{
  public SplashScreen()
  {
    this.InitializeComponent();
  }
}

After:

public sealed partial class SplashScreen : WinUIEx.SplashScreen
{
  public SplashScreen(Type window) : base(window)
  {
    this.InitializeComponent();
  }
}

Next in App.xaml.cs, change OnLaunched from:

protected override void OnLaunched(Microsoft.UI.Xaml.LaunchActivatedEventArgs args)
{
  m_window = new MainWindow();
  m_window.Activate();
}

To:

protected override void OnLaunched(Microsoft.UI.Xaml.LaunchActivatedEventArgs args)
{
  var splash = new SplashScreen(typeof(MainWindow));
  splash.Completed += (s, e) => m_window = e;
}

Lastly, override OnLoading, to create some long-running setup work - once this method completes, the splash screen will close and the window in the type parameter will launch.

Example:

protected override async Task OnLoading()
{
  //TODO: Do some actual work
  for (int i = 0; i < 100; i+=5)
  {
    statusText.Text = $"Loading {i}%...";
    progressBar.Value = i;
    await Task.Delay(50);
  }
}