新批次的夜间模式适配代码

lib/main.dart

@@ -1,16 +1,49 @@
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 import 'pages/battery_health_page.dart';
 import 'services/saf_storage_service.dart';
 
+// 🆕 1.7.0 全局 Key，用于从子页面切换主题
+final GlobalKey<_MyAppState> appKey = GlobalKey<_MyAppState>();
+
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
   await SafStorageService().init();
-  runApp(const MyApp());
+
+  final prefs = await SharedPreferences.getInstance();
+  final themeModeIndex = prefs.getInt('themeMode') ?? 0;
+  final themeMode =
+      ThemeMode.values[themeModeIndex.clamp(0, ThemeMode.values.length - 1)];
+
+  runApp(MyApp(key: appKey, initialThemeMode: themeMode));
 }
 
-class MyApp extends StatelessWidget {
-  const MyApp({super.key});
+class MyApp extends StatefulWidget {
+  final ThemeMode initialThemeMode;
+  const MyApp({super.key, required this.initialThemeMode});
+
+  @override
+  State<MyApp> createState() => _MyAppState();
+}
+
+class _MyAppState extends State<MyApp> {
+  late ThemeMode _themeMode;
+
+  @override
+  void initState() {
+    super.initState();
+    _themeMode = widget.initialThemeMode;
+  }
+
+  void switchTheme(ThemeMode mode) {
+    setState(() {
+      _themeMode = mode;
+    });
+    SharedPreferences.getInstance().then((prefs) {
+      prefs.setInt('themeMode', mode.index);
+    });
+  }
 
   @override
   Widget build(BuildContext context) {
@@ -18,7 +51,7 @@ class MyApp extends StatelessWidget {
       title: '电池健康度',
       theme: _lightTheme(),
       darkTheme: _darkTheme(),
-      themeMode: ThemeMode.system, // 默认跟随系统
+      themeMode: _themeMode,
       home: const BatteryHealthPage(),
       debugShowCheckedModeBanner: false,
     );
@@ -41,6 +74,9 @@ class MyApp extends StatelessWidget {
       colorScheme: const ColorScheme.light(
         primary: Color(0xFF1A73E8),
         secondary: Color(0xFF1A73E8),
+        surface: Colors.white,
+        onSurface: Colors.black, // 🟢 主要文字色
+        onSurfaceVariant: Colors.black87,
       ),
       textTheme: const TextTheme(
         bodyLarge: TextStyle(color: Colors.black),
@@ -68,6 +104,9 @@ class MyApp extends StatelessWidget {
       colorScheme: const ColorScheme.dark(
         primary: Color(0xFF4FC3F7),
         secondary: Color(0xFF4FC3F7),
+        surface: Color(0xFF121212),
+        onSurface: Colors.white, // 🟢 主要文字色（夜间模式为白色）
+        onSurfaceVariant: Colors.white70,
       ),
       textTheme: const TextTheme(
         bodyLarge: TextStyle(color: Colors.white),