Updating navigation tree for settings with groupings

src/settings-ui/Settings.UI/SettingsXAML/Views/ShellPage.xaml.cs

@@ -277,7 +277,7 @@ private void OobeButton_Click(object sender, RoutedEventArgs e)
 
         private bool navigationViewInitialStateProcessed; // avoid announcing initial state of the navigation pane.
 
-        private void NavigationView_PaneOpened(Microsoft.UI.Xaml.Controls.NavigationView sender, object args)
+        private void NavigationView_PaneOpened(NavigationView sender, object args)
         {
             if (!navigationViewInitialStateProcessed)
             {
@@ -293,7 +293,7 @@ private void NavigationView_PaneOpened(Microsoft.UI.Xaml.Controls.NavigationView
 
             if (AutomationPeer.ListenerExists(AutomationEvents.MenuOpened))
             {
-                var loader = Helpers.ResourceLoaderInstance.ResourceLoader;
+                var loader = ResourceLoaderInstance.ResourceLoader;
                 peer.RaiseNotificationEvent(
                     AutomationNotificationKind.ActionCompleted,
                     AutomationNotificationProcessing.ImportantMostRecent,
@@ -302,7 +302,7 @@ private void NavigationView_PaneOpened(Microsoft.UI.Xaml.Controls.NavigationView
             }
         }
 
-        private void NavigationView_PaneClosed(Microsoft.UI.Xaml.Controls.NavigationView sender, object args)
+        private void NavigationView_PaneClosed(NavigationView sender, object args)
         {
             if (!navigationViewInitialStateProcessed)
             {
@@ -318,7 +318,7 @@ private void NavigationView_PaneClosed(Microsoft.UI.Xaml.Controls.NavigationView
 
             if (AutomationPeer.ListenerExists(AutomationEvents.MenuClosed))
             {
-                var loader = Helpers.ResourceLoaderInstance.ResourceLoader;
+                var loader = ResourceLoaderInstance.ResourceLoader;
                 peer.RaiseNotificationEvent(
                     AutomationNotificationKind.ActionCompleted,
                     AutomationNotificationProcessing.ImportantMostRecent,

src/settings-ui/Settings.UI/Strings/en-us/Resources.resw

@@ -59,10 +59,7 @@
             : using a System.ComponentModel.TypeConverter
             : and then encoded with base64 encoding.
     -->
-  <xsd:schema id="root"
-    xmlns=""
-    xmlns:xsd="http://www.w3.org/2001/XMLSchema"
-    xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
     <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
     <xsd:element name="root" msdata:IsDataSet="true">
       <xsd:complexType>
@@ -4563,4 +4560,19 @@ Activate by holding the key for the character you want to add an accent to, then
   <data name="GeneralPage_ViewDiagnosticDataViewerInfoButton.Content" xml:space="preserve">
     <value>Restart</value>
   </data>
-</root>
+  <data name="Shell_TopLevelAdvanced.Content" xml:space="preserve">
+    <value>Advanced</value>
+  </data>
+  <data name="Shell_TopLevelFileManagement.Content" xml:space="preserve">
+    <value>File Management</value>
+  </data>
+  <data name="Shell_TopLevelInputOutput.Content" xml:space="preserve">
+    <value>Input / Output</value>
+  </data>
+  <data name="Shell_TopLevelWindowsAndLayouts.Content" xml:space="preserve">
+    <value>Windowing &amp; Layouts</value>
+  </data>
+  <data name="Shell_TopLevelSystemTools.Content" xml:space="preserve">
+    <value>System Tools</value>
+  </data>
+</root>

src/settings-ui/Settings.UI/ViewModels/ShellViewModel.cs

@@ -111,7 +111,11 @@ private void OnItemInvoked(NavigationViewItemInvokedEventArgs args)
                             .OfType<NavigationViewItem>()
                             .First(menuItem => (string)menuItem.Content == (string)args.InvokedItem);
             var pageType = item.GetValue(NavHelper.NavigateToProperty) as Type;
-            NavigationService.Navigate(pageType);
+
+            if (pageType != null)
+            {
+                NavigationService.Navigate(pageType);
+            }
         }
 
         private void OnBackRequested(NavigationView sender, NavigationViewBackRequestedEventArgs args)