feat: WIP dialog window.

src/Ursa/Controls/Dialog/DialogBox.cs

@@ -1,5 +1,6 @@
 using Avalonia;
 using Avalonia.Controls;
+using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Controls.Shapes;
 using Avalonia.Media;
 
@@ -7,18 +8,46 @@ namespace Ursa.Controls;
 
 public static class DialogBox
 {
-    public static async Task ShowAsync()
+    public static async Task<TResult?> ShowAsync<TView, TViewModel, TResult>(TViewModel vm) where TView : Control, new()
     {
-        return;
+        var window = new DialogWindow()
+        {
+            Content = new TView()
+            {
+                DataContext = vm,
+            },
+            DataContext = vm,
+        };
+        var lifetime = Application.Current?.ApplicationLifetime;
+        if (lifetime is IClassicDesktopStyleApplicationLifetime classLifetime)
+        {
+            var main = classLifetime.MainWindow;
+            if (main is null)
+            {
+                window.Show();
+                return default(TResult);
+            }
+            else
+            {
+                var result = await window.ShowDialog<TResult>(main);
+                return result;
+            }
+        }
+        else
+        {
+            return default(TResult);
+        }
     }
-
-    public static async Task ShowAsync<TView, TViewModel>(TViewModel vm) 
-        where TView: Control, new()
-        where TViewModel: new()
+    
+    public static async Task<TResult> ShowAsync<TView, TViewModel, TResult>(Window owner, TViewModel vm) where 
+        TView: Control, new()
     {
-        TView t = new TView();
-        t.DataContext = vm;
+        var window = new DialogWindow();
+        window.Content = new TView();
+        window.DataContext = vm;
+        return await window.ShowDialog<TResult>(owner);
     }
+    
 
     public static async Task<object?> ShowOverlayAsync<TView, TViewModel>(TViewModel vm, string hostId)
         where TView : Control, new()