feat(category): 添加分类功能

- 新增分类列表页面和分类详情页面
- 实现分类数据的加载、刷新和展示
- 添加分类相关的数据模型、提供者和仓库
- 优化数据库操作，统一表名和查询条件

lib/database/item_category_table.dart

@@ -9,5 +9,5 @@ CREATE TABLE item_category (
 ''';
 
 const String insertDefaultCategory = '''
-INSERT INTO item_category (name, description) VALUES ('默认分类', '系统默认分类');
+INSERT INTO item_category (id, name, description) VALUES (0, '默认分类', '系统默认分类');
 ''';

lib/main.dart

@@ -1,22 +1,35 @@
 import 'package:flutter/material.dart';
+import 'package:item_tracker/provider/item_category_provider.dart';
 import 'package:item_tracker/provider/item_provider.dart';
 import 'package:item_tracker/repository/item_repository.dart';
+import 'package:item_tracker/repository/item_category_repository.dart';
 import 'package:item_tracker/screens/home_screen.dart';
 import 'package:provider/provider.dart';
 import 'database/sqlite_helper.dart';
 
 void main() async {
+  WidgetsFlutterBinding.ensureInitialized();
 
   final dbHelper = DatabaseHelper();
-  final repository = ItemRepository(dbHelper: dbHelper);
+  await dbHelper.database;
+
+  final itemRepository = ItemRepository(dbHelper: dbHelper);
+  final itemCategoryRepository = ItemCategoryRepository(dbHelper: dbHelper);
 
-  WidgetsFlutterBinding.ensureInitialized();
-  await DatabaseHelper().database;
   print('数据库初始化完成');
+
   runApp(
+    MultiProvider(
+      providers: [
         ChangeNotifierProvider(
-      create: (_) => ItemProvider(repository: repository),
-      child: MyApp(),),
+          create: (_) => ItemProvider(repository: itemRepository),
+        ),
+        ChangeNotifierProvider(
+          create: (_) => ItemCategoryProvider(repository: itemCategoryRepository),
+        ),
+      ],
+      child: MyApp(),
+    ),
   );
 }
 

lib/models/item_category_model.dart

@@ -16,11 +16,11 @@ class ItemCategory {
   // fromMap — 数据库 map -> Dart 对象
   factory ItemCategory.fromMap(Map<String, dynamic> map) {
     return ItemCategory(
-      id: map['id'] as int?,
-      name: map['name'] as String,
-      description: map['description'] as String?,
-      createdAt: map['created_at'] as String?,
-      updatedAt: map['updated_at'] as String?,
+      id: map['id'],
+      name: map['name'],
+      description: map['description'],
+      createdAt: map['created_at'],
+      updatedAt: map['updated_at'],
     );
   }
 

lib/provider/item_category_provider.dart

@@ -0,0 +1,39 @@
+import 'package:flutter/material.dart';
+
+import 'package:item_tracker/models/item_category_model.dart';
+import 'package:item_tracker/repository/item_category_repository.dart';
+
+class ItemCategoryProvider extends ChangeNotifier {
+  List<ItemCategory> _categories = [];
+
+  List<ItemCategory> get categories => _categories;
+
+  final ItemCategoryRepository repository;
+
+  ItemCategoryProvider({required this.repository});
+
+  Future<void> loadCategories() async {
+    _categories = await repository.getAll();
+    notifyListeners();
+  }
+
+  Future<void> addCategory(ItemCategory) async {
+    await repository.insert(ItemCategory);
+    await loadCategories();
+  }
+
+  Future<void> updateCategory(ItemCategory) async {
+    await repository.update(ItemCategory);
+    await loadCategories();
+  }
+
+  Future<void> deleteCategory(ItemCategory) async {
+    await repository.delete(ItemCategory.id!);
+    await loadCategories();
+  }
+
+  Future<ItemCategory?> getCategoryById(int id) async {
+    final data = await repository.getById(id);
+    return data;
+  }
+}

lib/repository/item_category_repository.dart

@@ -1,16 +1,24 @@
+import 'package:item_tracker/database/sqlite_helper.dart';
 import 'package:sqflite/sqflite.dart';
 
 import '../models/item_category_model.dart';
 
 class ItemCategoryRepository {
-  final Database db;
+  static const String _tableName = 'item_category';
+  static const String _whereId = 'id = ?';
 
-  ItemCategoryRepository(this.db);
+  final DatabaseHelper dbHelper;
+
+  ItemCategoryRepository({required this.dbHelper});
+
+  // 统一 Database getter
+  Future<Database> get _db async => await dbHelper.database;
 
   // 插入 (Create)
   Future<int> insert(ItemCategory category) async {
-    return await db.insert(
-      'item_category',
+    final db = await _db;
+    return db.insert(
+      _tableName,
       category.toMap(),
       conflictAlgorithm: ConflictAlgorithm.replace,
     );
@@ -18,15 +26,17 @@ class ItemCategoryRepository {
 
   // 查询全部 (Read All)
   Future<List<ItemCategory>> getAll() async {
-    final List<Map<String, dynamic>> maps = await db.query('item_category');
+    final db = await _db;
+    final maps = await db.query(_tableName);
     return maps.map((map) => ItemCategory.fromMap(map)).toList();
   }
 
   // 查询单个 (Read One by id)
   Future<ItemCategory?> getById(int id) async {
-    final List<Map<String, dynamic>> maps = await db.query(
-      'item_category',
-      where: 'id = ?',
+    final db = await _db;
+    final maps = await db.query(
+      _tableName,
+      where: _whereId,
       whereArgs: [id],
       limit: 1,
     );
@@ -38,19 +48,21 @@ class ItemCategoryRepository {
 
   // 更新 (Update)
   Future<int> update(ItemCategory category) async {
-    return await db.update(
-      'item_category',
+    final db = await _db;
+    return db.update(
+      _tableName,
       category.toMap(),
-      where: 'id = ?',
+      where: _whereId,
       whereArgs: [category.id],
     );
   }
 
   // 删除 (Delete)
   Future<int> delete(int id) async {
-    return await db.delete(
-      'item_category',
-      where: 'id = ?',
+    final db = await _db;
+    return db.delete(
+      _tableName,
+      where: _whereId,
       whereArgs: [id],
     );
   }

lib/screens/category_screens/category_screen.dart

@@ -1,42 +1,64 @@
 import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+
+import '../../provider/item_category_provider.dart';
+import 'detail_category_screen.dart';
+
+class CategoryScreen extends StatefulWidget {
+  @override
+  _CategoryScreenState createState() => _CategoryScreenState();
+}
+
+class _CategoryScreenState extends State<CategoryScreen> {
+  late ItemCategoryProvider _itemCategoryProvider;
+
+  @override
+  void initState() {
+    super.initState();
+    Future.microtask(() {
+      _itemCategoryProvider =
+          Provider.of<ItemCategoryProvider>(context, listen: false);
+      _itemCategoryProvider.loadCategories();
+    });
+  }
+
+  Future<void> _refreshData() async {
+    await _itemCategoryProvider.loadCategories(); // 刷新数据
+  }
 
-class CategoryScreen extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
-    const items = 20;
-
     return Scaffold(
       appBar: AppBar(
-        title: Text('分类'),
-      ),
-      body: LayoutBuilder(
-        builder: (context, constraints) {
-          return SingleChildScrollView(
-            child: ConstrainedBox(
-              constraints: BoxConstraints(minHeight: constraints.maxHeight),
-              child: Column(
-                mainAxisAlignment: MainAxisAlignment.spaceBetween,
-                crossAxisAlignment: CrossAxisAlignment.stretch,
-                children: List.generate(
-                  items,
-                  (index) => ItemWidget(text: 'Item $index'),
-                ),
+        title: Text('分类列表'),
       ),
+      body: Consumer<ItemCategoryProvider>(builder: (context, provider, _) {
+        final categories = provider.categories;
+
+        if (categories.isEmpty) {
+          return Center(child: Text("暂无分类"));
+        }
+
+        return RefreshIndicator(
+            onRefresh: _refreshData,
+            child: ListView(
+              children: categories.map((category) {
+                return ListTile(
+                  title: Text(category.name),
+                  subtitle: Text(category.description ?? ""),
+                  onTap: () {
+                    Navigator.push(
+                      context,
+                      MaterialPageRoute(
+                        builder: (context) =>
+                            DetailCategoryScreen(category: category),
                       ),
                     );
                   },
-      ),
+                );
+              }).toList(),
+            ));
+      }),
     );
   }
 }
-
-class ItemWidget extends StatelessWidget {
-  const ItemWidget({super.key, required this.text});
-
-  final String text;
-
-  @override
-  Widget build(BuildContext context) {
-    return Card(child: SizedBox(height: 100, child: Center(child: Text(text))));
-  }
-}

lib/screens/category_screens/detail_category_screen.dart

@@ -0,0 +1,26 @@
+import 'package:flutter/material.dart';
+import 'package:item_tracker/models/item_category_model.dart';
+
+class DetailCategoryScreen extends StatelessWidget {
+  final ItemCategory category;
+
+  DetailCategoryScreen({required this.category});
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text('分类详情'),
+      ),
+      body: Center(
+          child: Column(
+           children: [
+             Text('${category.name}'),
+             Text('${category.description}')
+           ],
+          ),
+      ),
+    );
+  }
+
+}