Get ContentControl navigation working

Hyperbar.UI.Windows/ViewModelContentBinder.cs

@@ -0,0 +1,31 @@
+using Microsoft.UI.Xaml;
+using System.Reflection;
+
+namespace Hyperbar.UI.Windows;
+
+public class ViewModelContentBinder(NavigationTargetCollection contents) : 
+    IViewModelContentBinder
+{
+    public void Bind(FrameworkElement view,
+        object context)
+    {
+        if (context.GetType().GetCustomAttributes<NavigationTargetAttribute>()
+            is IEnumerable<NavigationTargetAttribute> attributes)
+        {
+            foreach (NavigationTargetAttribute attribute in attributes)
+            {
+                if (view.FindName(attribute.Name) is FrameworkElement content)
+                {
+                    contents.Add(attribute.Name, content);
+                    void HandleUnloaded(object sender, RoutedEventArgs args)
+                    {
+                        view.Unloaded -= HandleUnloaded;
+                        contents.Remove(attribute.Name);
+                    }
+
+                    view.Unloaded += HandleUnloaded;
+                }
+            }
+        }
+    }
+}