搜索优化，首页云备份

lib/pages/main_content_page.dart

@@ -2,10 +2,13 @@ import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 import '../providers/app_provider.dart';
 import '../utils/user_prefs.dart';
+import '../utils/sync/webdav_service.dart';
+import '../utils/toast_util.dart';
 import 'movies/movie_tab_page.dart';
 import 'book/book_tab_page.dart';
 import 'note/note_tab_page.dart';
 import 'search_page.dart';
+import 'sync/webdav_sync_page.dart';
 
 /// 主内容页 - 观影/阅读/笔记标签页
 class MainContentPage extends StatefulWidget {
@@ -87,6 +90,8 @@ class _MainContentPageState extends State<MainContentPage> {
         return AppBar(
           title: Text(_getAppBarTitle(provider)),
           actions: [
+            // 云备份按钮
+            _buildCloudSyncButton(context),
             // 搜索按钮
             IconButton(
               icon: const Icon(Icons.search),
@@ -105,6 +110,301 @@ class _MainContentPageState extends State<MainContentPage> {
     );
   }
 
+  /// 构建云备份按钮
+  Widget _buildCloudSyncButton(BuildContext context) {
+    return PopupMenuButton<String>(
+      icon: const Icon(Icons.cloud_sync_outlined),
+      tooltip: '云备份',
+      offset: const Offset(0, 40),
+      shape: RoundedRectangleBorder(
+        borderRadius: BorderRadius.circular(12),
+      ),
+      itemBuilder: (context) => [
+        PopupMenuItem(
+          value: 'upload',
+          child: Row(
+            children: [
+              Container(
+                width: 32,
+                height: 32,
+                decoration: BoxDecoration(
+                  color: const Color(0xFFFAFAFA),
+                  borderRadius: BorderRadius.circular(8),
+                ),
+                child: const Icon(
+                  Icons.cloud_upload_outlined,
+                  size: 18,
+                  color: Color(0xFF666666),
+                ),
+              ),
+              const SizedBox(width: 12),
+              const Text(
+                '上传数据',
+                style: TextStyle(
+                  fontSize: 14,
+                  color: Color(0xFF1A1A1A),
+                ),
+              ),
+            ],
+          ),
+        ),
+        PopupMenuItem(
+          value: 'download',
+          child: Row(
+            children: [
+              Container(
+                width: 32,
+                height: 32,
+                decoration: BoxDecoration(
+                  color: const Color(0xFFFAFAFA),
+                  borderRadius: BorderRadius.circular(8),
+                ),
+                child: const Icon(
+                  Icons.cloud_download_outlined,
+                  size: 18,
+                  color: Color(0xFF666666),
+                ),
+              ),
+              const SizedBox(width: 12),
+              const Text(
+                '下载数据',
+                style: TextStyle(
+                  fontSize: 14,
+                  color: Color(0xFF1A1A1A),
+                ),
+              ),
+            ],
+          ),
+        ),
+        const PopupMenuDivider(),
+        PopupMenuItem(
+          value: 'settings',
+          child: Row(
+            children: [
+              Container(
+                width: 32,
+                height: 32,
+                decoration: BoxDecoration(
+                  color: const Color(0xFFFAFAFA),
+                  borderRadius: BorderRadius.circular(8),
+                ),
+                child: const Icon(
+                  Icons.settings_outlined,
+                  size: 18,
+                  color: Color(0xFF666666),
+                ),
+              ),
+              const SizedBox(width: 12),
+              const Text(
+                'WebDAV设置',
+                style: TextStyle(
+                  fontSize: 14,
+                  color: Color(0xFF1A1A1A),
+                ),
+              ),
+            ],
+          ),
+        ),
+      ],
+      onSelected: (value) async {
+        switch (value) {
+          case 'upload':
+            await _performSync(context, SyncDirection.upload);
+            break;
+          case 'download':
+            await _performSync(context, SyncDirection.download);
+            break;
+          case 'settings':
+            Navigator.push(
+              context,
+              MaterialPageRoute(
+                builder: (context) => const WebDAVSyncPage(),
+              ),
+            );
+            break;
+        }
+      },
+    );
+  }
+
+  /// 执行同步操作
+  Future<void> _performSync(BuildContext context, SyncDirection direction) async {
+    // 检查是否已配置
+    final config = await WebDAVService.instance.getConfig();
+    if (config == null) {
+      if (context.mounted) {
+        _showResultDialog(
+          context,
+          title: '同步失败',
+          message: '请先配置 WebDAV 服务器',
+          isSuccess: false,
+        );
+      }
+      return;
+    }
+
+    // 显示加载对话框
+    if (context.mounted) {
+      showDialog(
+        context: context,
+        barrierDismissible: false,
+        builder: (context) => const Center(
+          child: CircularProgressIndicator(
+            color: Color(0xFF1A1A1A),
+          ),
+        ),
+      );
+    }
+
+    // 执行同步
+    final result = await WebDAVService.instance.syncData(direction: direction);
+
+    // 关闭加载对话框
+    if (context.mounted) {
+      Navigator.pop(context);
+    }
+
+    // 显示结果
+    if (context.mounted) {
+      final isSuccess = result.success;
+      final message = result.message.isNotEmpty ? result.message : (isSuccess ? '同步成功' : '同步失败');
+      
+      _showResultDialog(
+        context,
+        title: isSuccess ? '同步成功' : '同步失败',
+        message: message,
+        isSuccess: isSuccess,
+        details: {
+          'uploaded': result.uploadedFiles + result.uploadedImages,
+          'downloaded': result.downloadedFiles + result.downloadedImages,
+        },
+      );
+    }
+  }
+
+  /// 显示同步结果对话框
+  void _showResultDialog(
+    BuildContext context, {
+    required String title,
+    required String message,
+    required bool isSuccess,
+    Map<String, dynamic>? details,
+  }) {
+    showDialog(
+      context: context,
+      builder: (context) => AlertDialog(
+        backgroundColor: Colors.white,
+        elevation: 0,
+        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
+        title: Row(
+          children: [
+            Container(
+              width: 40,
+              height: 40,
+              decoration: BoxDecoration(
+                color: isSuccess ? const Color(0xFFE8F5E9) : const Color(0xFFFFEBEE),
+                borderRadius: BorderRadius.circular(10),
+              ),
+              child: Icon(
+                isSuccess ? Icons.check_circle : Icons.error,
+                color: isSuccess ? const Color(0xFF4CAF50) : const Color(0xFFE57373),
+                size: 24,
+              ),
+            ),
+            const SizedBox(width: 12),
+            Text(
+              title,
+              style: const TextStyle(
+                fontSize: 18,
+                fontWeight: FontWeight.w600,
+              ),
+            ),
+          ],
+        ),
+        content: Column(
+          mainAxisSize: MainAxisSize.min,
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            Text(
+              message,
+              style: const TextStyle(
+                fontSize: 14,
+                color: Color(0xFF666666),
+                height: 1.5,
+              ),
+            ),
+            if (details != null) ...[
+              const SizedBox(height: 16),
+              Container(
+                padding: const EdgeInsets.all(12),
+                decoration: BoxDecoration(
+                  color: const Color(0xFFFAFAFA),
+                  borderRadius: BorderRadius.circular(8),
+                ),
+                child: Column(
+                  crossAxisAlignment: CrossAxisAlignment.start,
+                  children: [
+                    if (details['uploaded'] != null)
+                      _buildDetailRow('上传文件', '${details['uploaded']} 个'),
+                    if (details['downloaded'] != null)
+                      _buildDetailRow('下载文件', '${details['downloaded']} 个'),
+                    if (details['conflicts'] != null)
+                      _buildDetailRow('冲突处理', '${details['conflicts']} 个'),
+                    if (details['errors'] != null && details['errors'] > 0)
+                      _buildDetailRow('错误', '${details['errors']} 个', isError: true),
+                  ],
+                ),
+              ),
+            ],
+          ],
+        ),
+        actions: [
+          ElevatedButton(
+            onPressed: () => Navigator.pop(context),
+            style: ElevatedButton.styleFrom(
+              backgroundColor: const Color(0xFF1A1A1A),
+              foregroundColor: Colors.white,
+              elevation: 0,
+              shape: RoundedRectangleBorder(
+                borderRadius: BorderRadius.circular(8),
+              ),
+              padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 12),
+            ),
+            child: const Text('确定'),
+          ),
+        ],
+        actionsPadding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
+      ),
+    );
+  }
+
+  /// 构建详情行
+  Widget _buildDetailRow(String label, String value, {bool isError = false}) {
+    return Padding(
+      padding: const EdgeInsets.symmetric(vertical: 4),
+      child: Row(
+        mainAxisAlignment: MainAxisAlignment.spaceBetween,
+        children: [
+          Text(
+            label,
+            style: const TextStyle(
+              fontSize: 13,
+              color: Color(0xFF999999),
+            ),
+          ),
+          Text(
+            value,
+            style: TextStyle(
+              fontSize: 13,
+              fontWeight: FontWeight.w600,
+              color: isError ? const Color(0xFFE57373) : const Color(0xFF1A1A1A),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+
   /// 获取 AppBar 标题
   String _getAppBarTitle(AppProvider provider) {
     switch (provider.mainTabIndex) {

lib/pages/search_page.dart

@@ -87,16 +87,20 @@ class _SearchPageState extends State<SearchPage> {
   }
 
   bool _matchNote(Note note, String keyword) {
+    // 搜索框为空且不选标签时，不显示任何笔记
+    if (keyword.isEmpty && _selectedTag == null) {
+      return false;
+    }
     // 如果有选中的标签，先按标签筛选
     if (_selectedTag != null) {
       if (!note.tags.contains(_selectedTag)) {
         return false;
       }
-    }
-    // 关键词为空时，只按标签筛选
+      // 有标签但关键词为空时，只按标签筛选
       if (keyword.isEmpty) {
         return true;
       }
+    }
     // 按内容搜索
     return note.content.toLowerCase().contains(keyword.toLowerCase());
   }