代码优化

lib/models/data_models.dart

@@ -13,6 +13,16 @@ DateTime? _safeParseDate(String? str, {DateTime? fallback}) {
   return DateTime.tryParse(str)?.toLocal() ?? fallback;
 }
 
+/// 安全将动态值转为 double，失败时返回 fallback
+double? _safeParseDouble(dynamic value, {double? fallback}) {
+  if (value == null) return fallback;
+  if (value is double) return value;
+  if (value is int) return value.toDouble();
+  if (value is num) return value.toDouble();
+  if (value is String) return double.tryParse(value) ?? fallback;
+  return fallback;
+}
+
 /// 解析字符串列表（通用工具函数，不限于 Movie）
 List<String> parseStringListGeneric(dynamic data) {
   if (data == null) return [];
@@ -86,14 +96,14 @@ class Movie {
       genres: _parseStringList(json['genres']),
       alternateTitles: _parseStringList(json['alternate_titles']),
       summary: json['summary'],
-      rating: json['rating']?.toDouble(),
+      rating: _safeParseDouble(json['rating']),
       status: json['status'] ?? 'want_to_watch',
       category: json['category'] ?? 'movie',
       watchDate: _safeParseDate(json['watch_date']),
       createdAt: _safeParseDate(json['created_at'], fallback: DateTime.now())!,
       updatedAt: _safeParseDate(json['updated_at'], fallback: DateTime.now())!,
       isDeleted: json['is_deleted'] == 1 || json['is_deleted'] == true,
-      coverOffset: (json['cover_offset'] ?? 0.0).toDouble(),
+      coverOffset: _safeParseDouble(json['cover_offset'], fallback: 0.0)!,
     );
   }
 
@@ -224,14 +234,14 @@ class Book {
       publisher: json['publisher'],
       genres: Movie.parseStringList(json['genres']),
       summary: json['summary'],
-      rating: json['rating']?.toDouble(),
+      rating: _safeParseDouble(json['rating']),
       status: json['status'] ?? 'want_to_read',
       isbn: json['isbn'],
       publishDate: _safeParseDate(json['publish_date']),
       createdAt: _safeParseDate(json['created_at'], fallback: DateTime.now())!,
       updatedAt: _safeParseDate(json['updated_at'], fallback: DateTime.now())!,
       isDeleted: json['is_deleted'] == 1 || json['is_deleted'] == true,
-      coverOffset: (json['cover_offset'] ?? 0.0).toDouble(),
+      coverOffset: _safeParseDouble(json['cover_offset'], fallback: 0.0)!,
     );
   }
 

lib/pages/profile_page.dart

@@ -67,7 +67,6 @@ class _ProfilePageState extends State<ProfilePage> with RouteAware {
 
   Future<void> _loadUserData() async {
     try {
-      await UserPrefs.init();
       setState(() {
         _nickname = _userPrefs.nickname;
         _motto = _userPrefs.motto;

lib/providers/app_provider.dart

@@ -194,6 +194,7 @@ class AppProvider extends ChangeNotifier {
   void setThemeMode(ThemeMode mode) {
     if (_themeMode != mode) {
       _themeMode = mode;
+      UserPrefs().setThemeMode(mode.index); // 0=system, 1=light, 2=dark
       notifyListeners();
     }
   }

lib/utils/database_helper.dart

@@ -9,6 +9,7 @@ class DatabaseHelper {
   static final DatabaseHelper instance = DatabaseHelper._init();
   static Database? _database;
   static Completer<void>? _reopenCompleter;
+  static Completer<Database>? _initCompleter;
 
   DatabaseHelper._init();
 
@@ -41,13 +42,28 @@ class DatabaseHelper {
   }
 
   Future<Database> get database async {
-    // 如果正在重开，等待完成（无忙等待）
+    // 如果正在重开，等待完成
     if (_reopenCompleter != null) {
       await _reopenCompleter!.future;
     }
     if (_database != null) return _database!;
-    _database = await _initDB('mooknote.db');
-    return _database!;
+
+    // 如果已有初始化在进行，等待它完成
+    if (_initCompleter != null) {
+      return _initCompleter!.future;
+    }
+
+    _initCompleter = Completer<Database>();
+    try {
+      _database = await _initDB('mooknote.db');
+      _initCompleter!.complete(_database!);
+      return _database!;
+    } catch (e) {
+      _initCompleter!.completeError(e);
+      rethrow;
+    } finally {
+      _initCompleter = null;
+    }
   }
 
   Future<Database> _initDB(String filePath) async {