check to see if dialog page is attached to window

src/Maui/Prism.Maui/Dialogs/DialogService.cs

@@ -1,4 +1,5 @@
 using Prism.Common;
+using Prism.Navigation;
 
 #nullable enable
 namespace Prism.Dialogs;
@@ -9,18 +10,36 @@ namespace Prism.Dialogs;
 public sealed class DialogService : DialogServiceBase
 {
     private readonly IPageAccessor _pageAccessor;
+    private readonly IWindowManager _windowManager;
 
     /// <summary>
     /// Creates a new instance of the <see cref="DialogService"/> for Maui Applications
     /// </summary>
     /// <param name="pageAccessor">The <see cref="IPageAccessor"/> used to determine where in the Navigation Stack we need to process the Dialog.</param>
+    /// <param name="windowManager">The <see cref="IWindowManager"/> used to resolve the current page when the scoped page is no longer attached.</param>
     /// <exception cref="ArgumentNullException">Throws when any constructor arguments are null.</exception>
-    public DialogService(IPageAccessor pageAccessor) 
+    public DialogService(IPageAccessor pageAccessor, IWindowManager windowManager)
     {
         ArgumentNullException.ThrowIfNull(pageAccessor);
+        ArgumentNullException.ThrowIfNull(windowManager);
         _pageAccessor = pageAccessor;
+        _windowManager = windowManager;
     }
 
     /// <inheritdoc/>
-    protected override Page? GetCurrentPage() => _pageAccessor.Page;
+    protected override Page? GetCurrentPage()
+    {
+        var page = _pageAccessor.Page;
+
+        // If the scoped page is still connected to a window, use it
+        if (page?.GetParentWindow() is not null)
+            return page;
+
+        // Fallback: the scoped page was detached (e.g. after absolute navigation).
+        // Resolve the current page from the active window instead.
+        if (_windowManager.Current is PrismWindow prismWindow)
+            return prismWindow.CurrentPage;
+
+        return page;
+    }
 }