NavigationView: re-prepare NavigationViewItems on every load and re-resolve the NavigationView for items moved between NavigationViews

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: ec9a38b2-2629-4a10-bfb5-552decfe6848

controls/dev/NavigationView/NavigationViewItem.cpp

@@ -173,18 +173,14 @@ void NavigationViewItem::LoadMenuItemsHost()
 
 void NavigationViewItem::OnLoaded(winrt::IInspectable const&, winrt::RoutedEventArgs const&)
 {
-    // Items in a NavigationView-owned repeater are prepared in OnApplyTemplate and refreshed by the repeater.
-    if (IsInNavigationViewOwnedRepeater() && m_splitViewIsPaneOpenChangedRevoker)
-    {
-        return;
-    }
-
     // If the NVI is not prepared in an ItemPresenter, it will not have reference to SplitView, so it is prepared here once
-    // NavigationViewItemBase::OnLoaded() has set the NavigationView. This also runs again when the item is loaded in a new host,
-    // so the closed compact state is recomputed for that host. Re-preparing replaces the SplitView subscriptions.
+    // NavigationViewItemBase::OnLoaded() has set the NavigationView. This also runs again when the item is loaded in a new host
+    // (for example moved between MenuItems, PaneFooter, Content or another NavigationView), so the SplitView subscriptions and
+    // the closed compact state follow the new host. Re-preparing replaces the previous SplitView subscriptions.
     if (auto splitView = GetSplitView())
     {
         PrepNavigationViewItem(splitView);
+        ReparentRepeater();
     }
 
     UpdateVisualStateForChevron();

controls/dev/NavigationView/NavigationViewItemBase.cpp

@@ -24,6 +24,15 @@ void NavigationViewItemBase::OnLoaded(winrt::IInspectable const&, winrt::RoutedE
     {
         SetNavigationViewParent(SharedHelpers::GetAncestorOfType<winrt::NavigationView>(*this));
     }
+    else if (!IsInNavigationViewOwnedRepeater())
+    {
+        // The item may have been moved to a different NavigationView. Keep the current reference if no ancestor is found
+        // (for example when the item is hosted in a popup).
+        if (auto const navigationView = SharedHelpers::GetAncestorOfType<winrt::NavigationView>(*this))
+        {
+            SetNavigationViewParent(navigationView);
+        }
+    }
 }
 
 NavigationViewRepeaterPosition NavigationViewItemBase::Position() const