fix: windows title bar theme switch (#936)

Author: crazy-zxx

ui/flutter/lib/app/modules/app/views/app_view.dart

@@ -2,10 +2,12 @@ import 'package:flutter/material.dart';
 import 'package:flutter_foreground_task/flutter_foreground_task.dart';
 import 'package:flutter_localizations/flutter_localizations.dart';
 import 'package:get/get.dart';
+import 'package:window_manager/window_manager.dart';  // Import the required packages
 
 import '../../../../i18n/message.dart';
 import '../../../../theme/theme.dart';
 import '../../../../util/locale_manager.dart';
+import '../../../../util/util.dart';  // Import the required packages
 import '../../../routes/app_pages.dart';
 import '../controllers/app_controller.dart';
 
@@ -32,6 +34,19 @@ class AppView extends GetView<AppController> {
         ],
         supportedLocales: messages.keys.keys.map((e) => toLocale(e)).toList(),
         getPages: AppPages.routes,
+
+        // Add listening to theme changes, set the title bar color according to the current system theme.
+        builder: (context, child) {
+          // if platform is desktop
+          if (Util.isDesktop()){
+            // actual brightness of the UI
+            Brightness brightness = Theme.of(context).brightness;
+            // Set the title bar to use the actual brightness of the UI
+            windowManager.setBrightness(brightness);
+          }
+          return child!;
+        },
+
       ),
     );
   }