Enable app elevation when deleting files (#4203)

Author: gave92

Files/Filesystem/FilesystemOperations/FilesystemOperations.cs

@@ -576,25 +576,41 @@ public async Task<IStorageHistory> DeleteAsync(IStorageItemWithPath source,
 
             if (fsResult == FileSystemStatusCode.Unauthorized)
             {
-                // Try again with fulltrust process
-                var elevateConfirmDialog = new Files.Dialogs.ElevateConfirmDialog();
-                var elevateConfirmResult = await elevateConfirmDialog.ShowAsync();
-                if (elevateConfirmResult == ContentDialogResult.Primary)
+                // Try again with fulltrust process (non admin: for shortcuts and hidden files)
+                if (associatedInstance.ServiceConnection != null)
                 {
-                    //await associatedInstance.ServiceConnection?.Elevate();
-                    App.InteractionViewModel.IsFullTrustElevated = true;
-
-                    if (associatedInstance.ServiceConnection != null)
+                    var (status, response) = await associatedInstance.ServiceConnection.SendMessageForResponseAsync(new ValueSet()
+                    {
+                        { "Arguments", "FileOperation" },
+                        { "fileop", "DeleteItem" },
+                        { "filepath", source.Path },
+                        { "permanently", permanently }
+                    });
+                    fsResult = (FilesystemResult)(status == AppServiceResponseStatus.Success
+                        && response.Get("Success", false));
+                }
+                if (!fsResult)
+                {
+                    var elevateConfirmDialog = new Files.Dialogs.ElevateConfirmDialog();
+                    var elevateConfirmResult = await elevateConfirmDialog.ShowAsync();
+                    if (elevateConfirmResult == ContentDialogResult.Primary)
                     {
-                        var (status, response) = await associatedInstance.ServiceConnection.SendMessageForResponseAsync(new ValueSet()
+                        if (await associatedInstance.ServiceConnection?.Elevate()) // TODO: enable this
                         {
-                            { "Arguments", "FileOperation" },
-                            { "fileop", "DeleteItem" },
-                            { "filepath", source.Path },
-                            { "permanently", permanently }
-                        });
-                        fsResult = (FilesystemResult)(status == AppServiceResponseStatus.Success
-                            && response.Get("Success", false));
+                            // Try again with fulltrust process (admin)
+                            if (associatedInstance.ServiceConnection != null)
+                            {
+                                var (status, response) = await associatedInstance.ServiceConnection.SendMessageForResponseAsync(new ValueSet()
+                                {
+                                    { "Arguments", "FileOperation" },
+                                    { "fileop", "DeleteItem" },
+                                    { "filepath", source.Path },
+                                    { "permanently", permanently }
+                                });
+                                fsResult = (FilesystemResult)(status == AppServiceResponseStatus.Success
+                                    && response.Get("Success", false));
+                            }
+                        }
                     }
                 }
             }

Files/Helpers/AppServiceConnectionHelper.cs

@@ -51,33 +51,39 @@ public static async Task<bool> Elevate(this NamedPipeAsAppServiceConnection conn
         {
             if (connection == null)
             {
+                App.InteractionViewModel.IsFullTrustElevated = false;
                 return false;
             }
 
+            bool wasElevated = false;
+
             var (status, response) = await connection.SendMessageForResponseAsync(new ValueSet() { { "Arguments", "Elevate" } });
             if (status == AppServiceResponseStatus.Success)
             {
                 var res = response.Get("Success", 1L);
                 switch (res)
                 {
-                    case 0:
+                    case 0: // FTP is restarting as admin
                         var nullConn = Task.FromResult<NamedPipeAsAppServiceConnection>(null);
                         ConnectionChanged?.Invoke(null, nullConn);
                         (await Instance)?.Dispose();
                         Instance = BuildConnection(false); // Fulltrust process is already running
                         _ = await Instance;
                         ConnectionChanged?.Invoke(null, Instance);
+                        wasElevated = true;
+                        break;
+                    case -1: // FTP is already admin
+                        wasElevated = true;
+                        break;
+                    default: // Failed (e.g canceled UAC)
+                        wasElevated = false;
                         break;
-
-                    case -1:
-                        return true;
-
-                    default:
-                        return false;
                 }
             }
 
-            return false;
+            App.InteractionViewModel.IsFullTrustElevated = wasElevated;
+
+            return wasElevated;
         }
 
         private static async Task<NamedPipeAsAppServiceConnection> BuildConnection(bool launchFullTrust)