Add project files.

Framework/Avalonia/Routing/Router.cs

@@ -0,0 +1,37 @@
+using Avalonia.Controls.Primitives;
+using Avalonia.Interactivity;
+
+namespace TheXamlGuy.Framework.Avalonia;
+
+public class Router : IRouter
+{
+    private readonly IRouteDescriptorCollection routes;
+
+    public Router(IRouteDescriptorCollection routes)
+    {
+        this.routes = routes;
+    }
+
+    public void Add(string name, object route)
+    {
+        if (route is TemplatedControl control)
+        {
+            void HandleUnloaded(object? sender, RoutedEventArgs args)
+            {
+                if (routes.FirstOrDefault(x => x.Route == sender) is IRouteDescriptor descriptor)
+                {
+                    routes.Remove(descriptor);
+                }
+            }
+
+            control.Unloaded += HandleUnloaded;
+        }
+
+        if (routes.FirstOrDefault(x => x.Name == name) is IRouteDescriptor descriptor)
+        {
+            routes.Remove(descriptor);
+        }
+
+        routes.Add(new RouteDescriptor(name, route));
+    }
+}