降低安装包体积，更改问本地选择字体

lib/pages/font_picker_page.dart

@@ -0,0 +1,399 @@
+import 'dart:io';
+import 'package:flutter/material.dart';
+import 'package:file_picker/file_picker.dart';
+import 'package:path/path.dart' as path;
+import 'package:permission_handler/permission_handler.dart';
+import '../utils/font_download_manager.dart';
+import '../utils/toast_util.dart';
+
+/// 字体选择页面
+///
+/// 用户输入或选择字体目录，遍历目录下的字体文件，点击即可加载使用。
+class FontPickerPage extends StatefulWidget {
+  final String? initialFamily;
+  const FontPickerPage({super.key, this.initialFamily});
+
+  @override
+  State<FontPickerPage> createState() => _FontPickerPageState();
+}
+
+class _FontPickerPageState extends State<FontPickerPage> {
+  final TextEditingController _pathController = TextEditingController();
+  final FontDownloadManager _fontManager = FontDownloadManager();
+
+  List<FontFileInfo> _fonts = [];
+  String? _loadingPath;
+  String? _selectedFamily;
+  bool _isScanning = false;
+
+  @override
+  void initState() {
+    super.initState();
+    _selectedFamily = widget.initialFamily;
+    // 默认填入内置字体目录
+    _pathController.text = '/sdcard/Documents/mooknote/fonts';
+    _checkPermissionAndScan();
+  }
+
+  @override
+  void dispose() {
+    _pathController.dispose();
+    super.dispose();
+  }
+
+  /// 请求存储权限（Android 11+ 需要 MANAGE_EXTERNAL_STORAGE）
+  Future<bool> _requestStoragePermission() async {
+    if (!Platform.isAndroid) return true;
+
+    var status = await Permission.manageExternalStorage.status;
+    if (status.isGranted) return true;
+
+    status = await Permission.manageExternalStorage.request();
+    if (status.isGranted) return true;
+
+    status = await Permission.storage.status;
+    if (status.isGranted) return true;
+
+    status = await Permission.storage.request();
+    return status.isGranted;
+  }
+
+  /// 检查权限并扫描
+  Future<void> _checkPermissionAndScan() async {
+    final hasPermission = await _requestStoragePermission();
+    if (!hasPermission) {
+      if (mounted) {
+        _showPermissionDialog();
+      }
+      return;
+    }
+    await _scanDirectory();
+  }
+
+  /// 显示权限提示弹窗
+  void _showPermissionDialog() {
+    final colors = Theme.of(context).colorScheme;
+    showDialog(
+      context: context,
+      builder: (ctx) => AlertDialog(
+        backgroundColor: colors.surface,
+        elevation: 0,
+        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
+        title: Text('需要存储权限',
+            style: TextStyle(fontSize: 16, fontWeight: FontWeight.w600, color: colors.onSurface)),
+        content: Text(
+          'Android 11+ 需要在系统设置中授予"所有文件访问权限"才能扫描字体文件。\n\n是否前往设置？',
+          style: TextStyle(fontSize: 14, color: colors.onSurface.withValues(alpha: 0.6), height: 1.6),
+        ),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.pop(ctx),
+            child: Text('取消', style: TextStyle(color: colors.onSurface.withValues(alpha: 0.4))),
+          ),
+          TextButton(
+            onPressed: () {
+              Navigator.pop(ctx);
+              openAppSettings();
+            },
+            child: Text('前往设置', style: TextStyle(color: colors.primary)),
+          ),
+        ],
+      ),
+    );
+  }
+
+  /// 扫描目录字体
+  Future<void> _scanDirectory() async {
+    final dirPath = _pathController.text.trim();
+    if (dirPath.isEmpty) {
+      if (mounted) ToastUtil.show(context, '请输入目录路径');
+      return;
+    }
+
+    setState(() => _isScanning = true);
+    try {
+      final fonts = await _fontManager.scanFontDirectory(dirPath);
+      if (mounted) {
+        setState(() {
+          _fonts = fonts;
+          _isScanning = false;
+        });
+        if (fonts.isEmpty) {
+          ToastUtil.show(context, '未找到字体文件');
+        }
+      }
+    } catch (e) {
+      if (mounted) {
+        setState(() => _isScanning = false);
+        ToastUtil.show(context, '扫描失败: $e');
+      }
+    }
+  }
+
+  /// 使用 file_picker 选择目录
+  Future<void> _pickDirectory() async {
+    final hasPermission = await _requestStoragePermission();
+    if (!hasPermission) {
+      if (mounted) _showPermissionDialog();
+      return;
+    }
+    try {
+      final result = await FilePicker.platform.getDirectoryPath();
+      if (result != null && result.isNotEmpty) {
+        _pathController.text = result;
+        await _scanDirectory();
+      }
+    } catch (e) {
+      if (mounted) ToastUtil.show(context, '选择目录失败: $e');
+    }
+  }
+
+  /// 加载并应用字体
+  Future<void> _loadFont(FontFileInfo font) async {
+    if (_loadingPath != null) return; // 防止重复点击
+
+    setState(() => _loadingPath = font.path);
+    try {
+      final family = await _fontManager.loadFontFile(font.path);
+      if (family != null) {
+        setState(() => _selectedFamily = family);
+        if (mounted) {
+          ToastUtil.show(context, '已应用: ${font.displayName}');
+          Navigator.pop(context, family);
+        }
+      } else {
+        if (mounted) ToastUtil.show(context, '字体加载失败');
+      }
+    } catch (e) {
+      if (mounted) ToastUtil.show(context, '加载失败: $e');
+    } finally {
+      setState(() => _loadingPath = null);
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final colors = Theme.of(context).colorScheme;
+    return Scaffold(
+      backgroundColor: colors.surface,
+      appBar: AppBar(
+        title: const Text('选择字体'),
+        actions: [
+          // 默认字体按钮
+          TextButton(
+            onPressed: () => Navigator.pop(context, ''),
+            child: Text(
+              '恢复默认',
+              style: TextStyle(
+                fontSize: 13,
+                color: colors.primary,
+                fontWeight: FontWeight.w500,
+              ),
+            ),
+          ),
+        ],
+      ),
+      body: Column(
+        children: [
+          // 路径输入区
+          Container(
+            padding: const EdgeInsets.fromLTRB(20, 16, 20, 12),
+            decoration: BoxDecoration(
+              color: colors.surface,
+              border: Border(
+                bottom: BorderSide(color: colors.outlineVariant, width: 0.5),
+              ),
+            ),
+            child: Column(
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: [
+                Text(
+                  '字体目录',
+                  style: TextStyle(
+                    fontSize: 12,
+                    fontWeight: FontWeight.w600,
+                    color: colors.onSurface.withValues(alpha: 0.5),
+                  ),
+                ),
+                const SizedBox(height: 8),
+                Row(
+                  children: [
+                    Expanded(
+                      child: TextField(
+                        controller: _pathController,
+                        style: TextStyle(fontSize: 13, color: colors.onSurface),
+                        decoration: InputDecoration(
+                          hintText: '输入字体目录路径',
+                          hintStyle: TextStyle(
+                            fontSize: 13,
+                            color: colors.onSurface.withValues(alpha: 0.3),
+                          ),
+                          filled: true,
+                          fillColor: colors.surfaceContainerHighest,
+                          contentPadding: const EdgeInsets.symmetric(
+                            horizontal: 12,
+                            vertical: 10,
+                          ),
+                          border: OutlineInputBorder(
+                            borderRadius: BorderRadius.circular(8),
+                            borderSide: BorderSide.none,
+                          ),
+                          suffixIcon: IconButton(
+                            icon: Icon(
+                              Icons.folder_open_outlined,
+                              size: 18,
+                              color: colors.onSurface.withValues(alpha: 0.5),
+                            ),
+                            onPressed: _pickDirectory,
+                          ),
+                        ),
+                        onSubmitted: (_) => _scanDirectory(),
+                      ),
+                    ),
+                    const SizedBox(width: 8),
+                    ElevatedButton(
+                      onPressed: _scanDirectory,
+                      style: ElevatedButton.styleFrom(
+                        backgroundColor: colors.primary,
+                        foregroundColor: colors.onPrimary,
+                        elevation: 0,
+                        padding: const EdgeInsets.symmetric(
+                          horizontal: 16,
+                          vertical: 10,
+                        ),
+                        shape: RoundedRectangleBorder(
+                          borderRadius: BorderRadius.circular(8),
+                        ),
+                      ),
+                      child: const Text('扫描', style: TextStyle(fontSize: 13)),
+                    ),
+                  ],
+                ),
+              ],
+            ),
+          ),
+
+          // 字体列表
+          Expanded(
+            child: _isScanning
+                ? Center(
+                    child: CircularProgressIndicator(
+                      strokeWidth: 2,
+                      color: colors.primary,
+                    ),
+                  )
+                : _fonts.isEmpty
+                    ? _buildEmptyState(colors)
+                    : ListView.separated(
+                        padding: const EdgeInsets.symmetric(vertical: 8),
+                        itemCount: _fonts.length,
+                        separatorBuilder: (_, __) => Divider(
+                          height: 0.5,
+                          indent: 20,
+                          endIndent: 20,
+                          color: colors.outlineVariant,
+                        ),
+                        itemBuilder: (_, index) => _buildFontItem(
+                          _fonts[index],
+                          colors,
+                        ),
+                      ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  Widget _buildEmptyState(ColorScheme colors) {
+    return Center(
+      child: Column(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          Icon(
+            Icons.folder_open_outlined,
+            size: 48,
+            color: colors.onSurface.withValues(alpha: 0.15),
+          ),
+          const SizedBox(height: 16),
+          Text(
+            '未找到字体文件',
+            style: TextStyle(
+              fontSize: 14,
+              color: colors.onSurface.withValues(alpha: 0.4),
+            ),
+          ),
+          const SizedBox(height: 4),
+          Text(
+            '支持 .ttf / .otf / .ttc 格式',
+            style: TextStyle(
+              fontSize: 12,
+              color: colors.onSurface.withValues(alpha: 0.25),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
+  Widget _buildFontItem(FontFileInfo font, ColorScheme colors) {
+    final isLoading = _loadingPath == font.path;
+    final isSelected = _selectedFamily != null &&
+        path.basenameWithoutExtension(font.fileName) == _selectedFamily;
+
+    return ListTile(
+      contentPadding: const EdgeInsets.symmetric(horizontal: 20, vertical: 4),
+      leading: Container(
+        width: 40,
+        height: 40,
+        decoration: BoxDecoration(
+          color: isSelected
+              ? colors.primary.withValues(alpha: 0.1)
+              : colors.surfaceContainerHighest,
+          borderRadius: BorderRadius.circular(10),
+          border: isSelected
+              ? Border.all(color: colors.primary.withValues(alpha: 0.3), width: 1)
+              : null,
+        ),
+        child: isLoading
+            ? Center(
+                child: SizedBox(
+                  width: 18,
+                  height: 18,
+                  child: CircularProgressIndicator(
+                    strokeWidth: 2,
+                    color: colors.primary,
+                  ),
+                ),
+              )
+            : Icon(
+                Icons.font_download_outlined,
+                size: 18,
+                color: isSelected
+                    ? colors.primary
+                    : colors.onSurface.withValues(alpha: 0.5),
+              ),
+      ),
+      title: Text(
+        font.displayName,
+        style: TextStyle(
+          fontSize: 14,
+          fontWeight: isSelected ? FontWeight.w600 : FontWeight.w400,
+          color: colors.onSurface,
+        ),
+      ),
+      subtitle: Text(
+        font.fileName,
+        style: TextStyle(
+          fontSize: 11,
+          color: colors.onSurface.withValues(alpha: 0.35),
+        ),
+        maxLines: 1,
+        overflow: TextOverflow.ellipsis,
+      ),
+      trailing: isSelected
+          ? Icon(Icons.check_circle, size: 18, color: colors.primary)
+          : null,
+      onTap: isLoading ? null : () => _loadFont(font),
+    );
+  }
+}

lib/pages/profile_page.dart

@@ -7,6 +7,7 @@ import 'package:path/path.dart' as path;
 import 'package:provider/provider.dart';
 import 'package:webview_flutter/webview_flutter.dart';
 import 'package:url_launcher/url_launcher.dart';
+import 'package:permission_handler/permission_handler.dart';
 import '../main.dart' show routeObserver;
 import '../models/data_models.dart';
 import '../providers/app_provider.dart';
@@ -25,6 +26,7 @@ import 'sync/cloud_sync_page.dart';
 import 'app_icon_picker_page.dart';
 import 'tag_management_page.dart';
 import 'stroll_page.dart';
+import 'font_picker_page.dart';
 
 /// 个人中心页面
 class ProfilePage extends StatefulWidget {
@@ -680,11 +682,7 @@ class _ProfilePageState extends State<ProfilePage> with RouteAware {
         () => Navigator.push(
             context, MaterialPageRoute(builder: (_) => const SettingsPage()))
       ),
-      (
+      (Icons.feedback_outlined, '反馈', () => _showFeedbackDialog(context)),
-        Icons.feedback_outlined,
-        '反馈',
-        () => _showFeedbackDialog(context)
-      ),
     ];
 
     return Padding(
@@ -808,7 +806,8 @@ class _ProfilePageState extends State<ProfilePage> with RouteAware {
                         Text('作者邮箱',
                             style: TextStyle(
                                 fontSize: 12,
-                                color: colors.onSurface.withValues(alpha: 0.5))),
+                                color:
+                                    colors.onSurface.withValues(alpha: 0.5))),
                         const SizedBox(height: 2),
                         Text(email,
                             style: TextStyle(
@@ -824,7 +823,8 @@ class _ProfilePageState extends State<ProfilePage> with RouteAware {
                       ToastUtil.show(context, '已复制到剪贴板');
                     },
                     child: Container(
-                      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
+                      padding: const EdgeInsets.symmetric(
+                          horizontal: 12, vertical: 6),
                       decoration: BoxDecoration(
                         color: colors.primary.withValues(alpha: 0.08),
                         borderRadius: BorderRadius.circular(8),
@@ -834,7 +834,11 @@ class _ProfilePageState extends State<ProfilePage> with RouteAware {
                         children: [
                           Icon(Icons.copy, size: 14, color: colors.primary),
                           const SizedBox(width: 4),
-                          Text('复制', style: TextStyle(fontSize: 12, color: colors.primary, fontWeight: FontWeight.w600)),
+                          Text('复制',
+                              style: TextStyle(
+                                  fontSize: 12,
+                                  color: colors.primary,
+                                  fontWeight: FontWeight.w600)),
                         ],
                       ),
                     ),
@@ -864,7 +868,8 @@ class _ProfilePageState extends State<ProfilePage> with RouteAware {
                         Text('QQ 群',
                             style: TextStyle(
                                 fontSize: 12,
-                                color: colors.onSurface.withValues(alpha: 0.5))),
+                                color:
+                                    colors.onSurface.withValues(alpha: 0.5))),
                         const SizedBox(height: 2),
                         Text('1087203310',
                             style: TextStyle(
@@ -880,7 +885,8 @@ class _ProfilePageState extends State<ProfilePage> with RouteAware {
                       ToastUtil.show(context, '已复制到剪贴板');
                     },
                     child: Container(
-                      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
+                      padding: const EdgeInsets.symmetric(
+                          horizontal: 12, vertical: 6),
                       decoration: BoxDecoration(
                         color: colors.primary.withValues(alpha: 0.08),
                         borderRadius: BorderRadius.circular(8),
@@ -890,7 +896,11 @@ class _ProfilePageState extends State<ProfilePage> with RouteAware {
                         children: [
                           Icon(Icons.copy, size: 14, color: colors.primary),
                           const SizedBox(width: 4),
-                          Text('复制', style: TextStyle(fontSize: 12, color: colors.primary, fontWeight: FontWeight.w600)),
+                          Text('复制',
+                              style: TextStyle(
+                                  fontSize: 12,
+                                  color: colors.primary,
+                                  fontWeight: FontWeight.w600)),
                         ],
                       ),
                     ),
@@ -1225,6 +1235,17 @@ class _SettingsPageState extends State<SettingsPage> {
             subtitle: '清理未在数据库中引用的文件',
             onTap: () => _showClearCacheDialog(context),
           ),
+          Divider(
+              height: 0.5,
+              indent: 24,
+              endIndent: 24,
+              color: colors.outlineVariant),
+          _buildActionItem(
+            icon: Icons.folder_outlined,
+            title: '获取系统权限',
+            subtitle: '前往系统设置开启存储权限',
+            onTap: _showStoragePermissionDialog,
+          ),
           Divider(
               height: 0.5,
               indent: 24,
@@ -1758,28 +1779,20 @@ class _SettingsPageState extends State<SettingsPage> {
 
   // ─── 字体选择器 ───
 
-  static const _fontLabels = ['默认字体', '霞鹜文楷', 'OPPO Sans', '思源宋体', '得意黑'];
-  static const _fontValues = [
-    '',
-    'LXGWWenKai',
-    'OPPOSans',
-    'NotoSerifSC',
-    'SmileySans'
-  ];
-  static const _fontIcons = [
-    Icons.font_download_outlined,
-    Icons.brush_outlined,
-    Icons.phone_android,
-    Icons.text_fields,
-    Icons.emoji_emotions_outlined
-  ];
-
   Widget _buildFontSelector() {
     final colors = Theme.of(context).colorScheme;
-    final idx = _fontValues.indexOf(_fontFamily);
+    final label = _fontFamily.isEmpty ? '系统默认' : _fontFamily;
-    final label = idx >= 0 ? _fontLabels[idx] : '系统默认';
     return InkWell(
-      onTap: _showFontPicker,
+      onTap: () async {
+        final result = await Navigator.push<String>(
+          context,
+          MaterialPageRoute(
+              builder: (_) => const FontPickerPage(initialFamily: '')),
+        );
+        if (result != null && mounted) {
+          _setFontFamily(result);
+        }
+      },
       child: Container(
         padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 10),
         child: Row(children: [
@@ -1814,76 +1827,6 @@ class _SettingsPageState extends State<SettingsPage> {
     );
   }
 
-  void _showFontPicker() {
-    final colors = Theme.of(context).colorScheme;
-    showModalBottomSheet(
-      context: context,
-      backgroundColor: Colors.transparent,
-      builder: (ctx) => Container(
-        decoration: BoxDecoration(
-            color: colors.surface,
-            borderRadius:
-                const BorderRadius.vertical(top: Radius.circular(16))),
-        padding: const EdgeInsets.only(bottom: 20),
-        child: Column(mainAxisSize: MainAxisSize.min, children: [
-          Container(
-              width: 36,
-              height: 4,
-              margin: const EdgeInsets.only(top: 12, bottom: 16),
-              decoration: BoxDecoration(
-                  color: colors.onSurface.withValues(alpha: 0.15),
-                  borderRadius: BorderRadius.circular(2))),
-          Padding(
-              padding: const EdgeInsets.symmetric(horizontal: 24),
-              child: Align(
-                  alignment: Alignment.centerLeft,
-                  child: Text('字体',
-                      style: TextStyle(
-                          fontSize: 14,
-                          fontWeight: FontWeight.w600,
-                          color: colors.onSurface)))),
-          const SizedBox(height: 8),
-          for (int i = 0; i < _fontLabels.length; i++) ...[
-            if (i > 0)
-              Divider(
-                  height: 0.5,
-                  indent: 24,
-                  endIndent: 24,
-                  color: colors.outlineVariant),
-            ListTile(
-              contentPadding: const EdgeInsets.symmetric(horizontal: 24),
-              leading: Container(
-                  width: 36,
-                  height: 36,
-                  decoration: BoxDecoration(
-                      color: colors.surfaceContainerHighest,
-                      borderRadius: BorderRadius.circular(10)),
-                  child: Icon(_fontIcons[i],
-                      size: 20,
-                      color: _fontFamily == _fontValues[i]
-                          ? colors.primary
-                          : colors.onSurface.withValues(alpha: 0.6))),
-              title: Text(_fontLabels[i],
-                  style: TextStyle(
-                      fontSize: 14,
-                      fontWeight: _fontFamily == _fontValues[i]
-                          ? FontWeight.w600
-                          : FontWeight.w400,
-                      color: colors.onSurface)),
-              trailing: _fontFamily == _fontValues[i]
-                  ? Icon(Icons.check, size: 20, color: colors.primary)
-                  : null,
-              onTap: () {
-                Navigator.pop(ctx);
-                _setFontFamily(_fontValues[i]);
-              },
-            ),
-          ],
-        ]),
-      ),
-    );
-  }
-
   void _setFontFamily(String family) {
     setState(() => _fontFamily = family);
     context.read<AppProvider>().setFontFamily(family);
@@ -2040,6 +1983,46 @@ class _SettingsPageState extends State<SettingsPage> {
     );
   }
 
+  void _showStoragePermissionDialog() {
+    final colors = Theme.of(context).colorScheme;
+    showDialog(
+      context: context,
+      builder: (ctx) => AlertDialog(
+        backgroundColor: colors.surface,
+        elevation: 0,
+        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
+        title: Text('需要存储权限',
+            style: TextStyle(
+                fontSize: 16,
+                fontWeight: FontWeight.w600,
+                color: colors.onSurface)),
+        content: Text(
+          'Android 11+ 需要在系统设置中授予"所有文件访问权限"才能扫描字体文件。\n\n是否前往设置？',
+          style: TextStyle(
+              fontSize: 14,
+              color: colors.onSurface.withValues(alpha: 0.6),
+              height: 1.6),
+        ),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.pop(ctx),
+            child: Text('取消',
+                style:
+                    TextStyle(color: colors.onSurface.withValues(alpha: 0.4))),
+          ),
+          TextButton(
+            onPressed: () {
+              Navigator.pop(ctx);
+              // 跳转到应用设置页（用户可在权限中找到"所有文件访问"）
+              openAppSettings();
+            },
+            child: Text('前往设置', style: TextStyle(color: colors.primary)),
+          ),
+        ],
+      ),
+    );
+  }
+
   void _showClearCacheDialog(BuildContext pageContext) {
     final colors = Theme.of(context).colorScheme;
     showDialog(
@@ -2174,8 +2157,8 @@ class _SettingsPageState extends State<SettingsPage> {
     try {
       final db = await DatabaseHelper.instance.database;
       // 收集数据库中所有引用的 epub_books 子目录名（包括软删除的）
-      final rows = await db
+      final rows = await db.query('reader_books',
-          .query('reader_books', columns: ['id', 'file_path', 'cover_path', 'is_deleted']);
+          columns: ['id', 'file_path', 'cover_path', 'is_deleted']);
       final usedDirs = <String>{};
       for (final r in rows) {
         // 只收集未删除的记录对应的目录

lib/providers/app_provider.dart

@@ -15,6 +15,7 @@ import '../utils/database_helper.dart';
 import '../utils/image_path_helper.dart';
 import '../utils/user_prefs.dart';
 import '../utils/theme/app_theme.dart';
+import '../utils/font_download_manager.dart';
 
 /// 应用全局状态管理
 class AppProvider extends ChangeNotifier {
@@ -255,6 +256,10 @@ class AppProvider extends ChangeNotifier {
     _colorSchemeIndex = prefs.colorSchemeIndex;
     _fontFamily = prefs.fontFamily;
     AppTheme.setFontFamily(_fontFamily);
+    // 异步预加载已缓存的字体（不阻塞 UI）
+    if (_fontFamily.isNotEmpty) {
+      FontDownloadManager().preloadCachedFont(_fontFamily);
+    }
     notifyListeners();
   }
 

lib/utils/font_download_manager.dart

@@ -0,0 +1,174 @@
+import 'dart:io';
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:path/path.dart' as path;
+import 'package:path_provider/path_provider.dart';
+
+/// 本地字体扫描与加载管理器
+///
+/// 扫描用户指定目录下的字体文件，通过 FontLoader 动态注册到 Flutter。
+class FontDownloadManager {
+  static final FontDownloadManager _instance = FontDownloadManager._internal();
+  factory FontDownloadManager() => _instance;
+  FontDownloadManager._internal();
+
+  /// 已加载的字体 family 集合（避免重复注册）
+  final Set<String> _loadedFonts = {};
+
+  /// 支持的字体文件扩展名
+  static const List<String> _fontExtensions = ['.ttf', '.otf', '.ttc'];
+
+  /// 扫描指定目录下的字体文件
+  Future<List<FontFileInfo>> scanFontDirectory(String dirPath) async {
+    final dir = Directory(dirPath);
+    if (!await dir.exists()) {
+      debugPrint('[FontScan] 目录不存在: $dirPath');
+      return [];
+    }
+
+    final fonts = <FontFileInfo>[];
+    try {
+      await for (final entity in dir.list(recursive: true)) {
+        if (entity is File) {
+          final ext = path.extension(entity.path).toLowerCase();
+          if (_fontExtensions.contains(ext)) {
+            final fileName = path.basename(entity.path);
+            fonts.add(FontFileInfo(
+              path: entity.path,
+              fileName: fileName,
+              displayName: _formatFontName(fileName),
+            ));
+          }
+        }
+      }
+    } catch (e) {
+      debugPrint('[FontScan] 扫描异常: $e');
+    }
+    // 按文件名排序
+    fonts.sort((a, b) => a.fileName.compareTo(b.fileName));
+    debugPrint('[FontScan] 扫描完成: $dirPath, 找到 ${fonts.length} 个字体文件');
+    return fonts;
+  }
+
+  /// 从字体文件名生成显示名称
+  String _formatFontName(String fileName) {
+    // 移除扩展名
+    var name = path.basenameWithoutExtension(fileName);
+    // 替换常见分隔符为空格
+    name = name.replaceAll('_', ' ').replaceAll('-', ' ');
+    // 首字母大写
+    return name.split(' ').map((w) {
+      if (w.isEmpty) return w;
+      return w[0].toUpperCase() + w.substring(1).toLowerCase();
+    }).join(' ');
+  }
+
+  /// 加载指定字体文件
+  ///
+  /// [filePath] 字体文件完整路径
+  /// [family] 可选的字体 family 名称（默认使用文件名）
+  ///
+  /// 返回加载成功后的 family 名称
+  Future<String?> loadFontFile(String filePath, {String? family}) async {
+    final file = File(filePath);
+    if (!await file.exists()) return null;
+
+    final fileName = path.basename(filePath);
+    final familyName = family ?? path.basenameWithoutExtension(fileName);
+
+    // 已加载过，直接返回
+    if (_loadedFonts.contains(familyName)) {
+      return familyName;
+    }
+
+    try {
+      final bytes = await file.readAsBytes();
+      final loader = FontLoader(familyName);
+      loader.addFont(Future.value(ByteData.sublistView(bytes)));
+      await loader.load();
+      _loadedFonts.add(familyName);
+      debugPrint('[FontDownload] 字体加载成功: $familyName');
+      return familyName;
+    } catch (e) {
+      debugPrint('[FontDownload] 字体加载失败: $familyName, error=$e');
+      return null;
+    }
+  }
+
+  /// 预加载已缓存的字体（应用启动时调用）
+  Future<void> preloadCachedFont(String family) async {
+    if (family.isEmpty) return;
+    if (_loadedFonts.contains(family)) return;
+
+    // 尝试从默认字体目录加载
+    try {
+      final fontDir = await _getFontDir();
+      final file = File(path.join(fontDir.path, '$family.ttf'));
+      if (await file.exists()) {
+        await loadFontFile(file.path, family: family);
+        return;
+      }
+      // 尝试其他扩展名
+      for (final ext in ['.otf', '.ttc']) {
+        final file2 = File(path.join(fontDir.path, '$family$ext'));
+        if (await file2.exists()) {
+          await loadFontFile(file2.path, family: family);
+          return;
+        }
+      }
+    } catch (e) {
+      debugPrint('[FontDownload] 预加载失败: $family, error=$e');
+    }
+  }
+
+  /// 获取字体缓存目录
+  Future<Directory> _getFontDir() async {
+    if (Platform.isAndroid) {
+      final fontDir = Directory('/sdcard/Documents/mooknote/fonts');
+      if (!await fontDir.exists()) {
+        await fontDir.create(recursive: true);
+      }
+      return fontDir;
+    }
+    // iOS / 桌面端 fallback
+    final appDir = await getApplicationDocumentsDirectory();
+    final fontDir = Directory(path.join(appDir.path, 'fonts'));
+    if (!await fontDir.exists()) {
+      await fontDir.create(recursive: true);
+    }
+    return fontDir;
+  }
+
+  /// 清理所有下载的字体缓存
+  Future<void> clearAllCache() async {
+    try {
+      final fontDir = await _getFontDir();
+      if (await fontDir.exists()) {
+        await for (final entity in fontDir.list()) {
+          if (entity is File) {
+            try {
+              await entity.delete();
+            } catch (_) {}
+          }
+        }
+      }
+      _loadedFonts.clear();
+      debugPrint('[FontDownload] 字体缓存已清理');
+    } catch (e) {
+      debugPrint('[FontDownload] 清理缓存失败: $e');
+    }
+  }
+}
+
+/// 字体文件信息
+class FontFileInfo {
+  final String path;
+  final String fileName;
+  final String displayName;
+
+  FontFileInfo({
+    required this.path,
+    required this.fileName,
+    required this.displayName,
+  });
+}

pubspec.lock

@@ -1,6 +1,14 @@
 # Generated by pub
 # See https://dart.dev/tools/pub/glossary#lockfile
 packages:
+  android_intent_plus:
+    dependency: "direct main"
+    description:
+      name: android_intent_plus
+      sha256: "2329378af63f49b985cb2e110ac784d08374f1e2b1984be77ba9325b1c8cce11"
+      url: "https://pub.dev"
+    source: hosted
+    version: "5.3.1"
   archive:
     dependency: "direct main"
     description:

pubspec.yaml

@@ -30,6 +30,7 @@ dependencies:
   flutter_staggered_grid_view: ^0.7.0
   http: ^1.2.0
   url_launcher: ^6.2.5
+  android_intent_plus: ^5.0.0
   webview_flutter: ^4.8.0
   flutter_inappwebview: ^6.1.5
   dynamic_color: ^1.8.1
@@ -62,17 +63,3 @@ flutter:
     - assets/images/
     - assets/icon/
     - assets/images/ticket/
-
-  fonts:
-    - family: LXGWWenKai
-      fonts:
-        - asset: assets/fonts/LXGWWenKai-Regular.ttf
-    - family: OPPOSans
-      fonts:
-        - asset: assets/fonts/OPPO_Sans4.0.ttf
-    - family: NotoSerifSC
-      fonts:
-        - asset: assets/fonts/NotoSerifSC-Regular.ttf
-    - family: SmileySans
-      fonts:
-        - asset: assets/fonts/SmileySans-Oblique.ttf