feat: cross platform projects.

demo/Ursa.Demo.Desktop/App.axaml.cs

@@ -0,0 +1,30 @@
+using Avalonia;
+using Avalonia.Controls.ApplicationLifetimes;
+using Avalonia.Markup.Xaml;
+using Ursa.Demo.ViewModels;
+using Ursa.Demo.Views;
+
+namespace Ursa.Demo.Desktop;
+
+public partial class App : Application
+{
+    public override void Initialize()
+    {
+        AvaloniaXamlLoader.Load(this);
+    }
+
+    public override void OnFrameworkInitializationCompleted()
+    {
+        if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
+        {
+            // Line below is needed to remove Avalonia data validation.
+            // Without this line you will get duplicate validations from both Avalonia and CT
+            desktop.MainWindow = new MainWindow
+            {
+                DataContext = new MainWindowViewModel(),
+            };
+        }
+
+        base.OnFrameworkInitializationCompleted();
+    }
+}