diff --git a/jive-flutter/lib/screens/theme_management_screen.dart b/jive-flutter/lib/screens/theme_management_screen.dart
index ccc09204..d5cef867 100644
--- a/jive-flutter/lib/screens/theme_management_screen.dart
+++ b/jive-flutter/lib/screens/theme_management_screen.dart
@@ -408,7 +408,7 @@ class _ThemeManagementScreenState extends State<ThemeManagementScreen>
       case 'eye_comfort':
         await ThemeService().applyEyeComfortTheme();
         if (mounted) {
-          ScaffoldMessenger.of(context).showSnackBar(
+          messenger.showSnackBar(
             const SnackBar(content: Text('已应用护眼主题')),
           );
         }
@@ -416,7 +416,7 @@ class _ThemeManagementScreenState extends State<ThemeManagementScreen>
       case 'apply_eye_bluegrey':
         await ThemeService().applyPresetTheme('preset_eye_bluegrey');
         if (mounted) {
-          ScaffoldMessenger.of(context).showSnackBar(
+          messenger.showSnackBar(
             const SnackBar(content: Text('已应用护眼·蓝灰')),
           );
         }
@@ -424,7 +424,7 @@ class _ThemeManagementScreenState extends State<ThemeManagementScreen>
       case 'apply_eye_green':
         await ThemeService().applyPresetTheme('preset_eye_green');
         if (mounted) {
-          ScaffoldMessenger.of(context).showSnackBar(
+          messenger.showSnackBar(
             const SnackBar(content: Text('已应用护眼·青绿')),
           );
         }
@@ -432,7 +432,7 @@ class _ThemeManagementScreenState extends State<ThemeManagementScreen>
       case 'apply_eye_dark':
         await ThemeService().applyPresetTheme('preset_eye_dark');
         if (mounted) {
-          ScaffoldMessenger.of(context).showSnackBar(
+          messenger.showSnackBar(
             const SnackBar(content: Text('已应用护眼·夜间')),
           );
         }
@@ -463,7 +463,7 @@ class _ThemeManagementScreenState extends State<ThemeManagementScreen>
     if (!mounted) return;
 
     if (result != null) {
-      ScaffoldMessenger.of(context).showSnackBar(
+      messenger.showSnackBar(
         SnackBar(
           content: Text('主题"${result.name}"创建成功'),
           backgroundColor: Colors.green,
@@ -481,7 +481,7 @@ class _ThemeManagementScreenState extends State<ThemeManagementScreen>
     if (!mounted) return;
 
     if (result != null) {
-      ScaffoldMessenger.of(context).showSnackBar(
+      messenger.showSnackBar(
         SnackBar(
           content: Text('主题"${result.name}"已更新'),
           backgroundColor: Colors.green,
@@ -498,6 +498,7 @@ class _ThemeManagementScreenState extends State<ThemeManagementScreen>
   }
 
   Future<void> _copyTheme(models.CustomThemeData theme) async {
+    final messenger = ScaffoldMessenger.of(context);
     try {
       final newTheme = await _themeService.createCustomTheme(
         name: '${theme.name} (副本)',
@@ -507,14 +508,14 @@ class _ThemeManagementScreenState extends State<ThemeManagementScreen>
       );
       if (!mounted) return;
 
-      ScaffoldMessenger.of(context).showSnackBar(
+      messenger.showSnackBar(
         SnackBar(
           content: Text('主题"${newTheme.name}"创建成功'),
           backgroundColor: Colors.green,
         ),
       );
     } catch (e) {
-      ScaffoldMessenger.of(context).showSnackBar(
+      messenger.showSnackBar(
         SnackBar(
           content: Text('复制失败: $e'),
           backgroundColor: Colors.red,
@@ -524,17 +525,18 @@ class _ThemeManagementScreenState extends State<ThemeManagementScreen>
   }
 
   Future<void> _exportTheme(models.CustomThemeData theme) async {
+    final messenger = ScaffoldMessenger.of(context);
     try {
       await _themeService.copyThemeToClipboard(theme.id);
-      if (!context.mounted) return;
-      ScaffoldMessenger.of(context).showSnackBar(
+      if (!mounted) return;
+      messenger.showSnackBar(
         const SnackBar(
           content: Text('主题已复制到剪贴板'),
           backgroundColor: Colors.green,
         ),
       );
     } catch (e) {
-      ScaffoldMessenger.of(context).showSnackBar(
+      messenger.showSnackBar(
         SnackBar(
           content: Text('导出失败: $e'),
           backgroundColor: Colors.red,
@@ -544,6 +546,10 @@ class _ThemeManagementScreenState extends State<ThemeManagementScreen>
   }
 
   Future<void> _deleteTheme(models.CustomThemeData theme) async {
+    final navigator = Navigator.of(context);
+    final messenger = ScaffoldMessenger.of(context);
+    final navigator = Navigator.of(context);
+    final messenger = ScaffoldMessenger.of(context);
     final confirmed = await showDialog<bool>(
       context: context,
       builder: (context) => AlertDialog(
@@ -551,11 +557,11 @@ class _ThemeManagementScreenState extends State<ThemeManagementScreen>
         content: Text('确定要删除主题"${theme.name}"吗？此操作不可撤销。'),
         actions: [
           TextButton(
-            onPressed: () => Navigator.of(context).pop(false),
+            onPressed: () => navigator.pop(false),
             child: const Text('取消'),
           ),
           ElevatedButton(
-            onPressed: () => Navigator.of(context).pop(true),
+            onPressed: () => navigator.pop(true),
             style: ElevatedButton.styleFrom(
               backgroundColor: Colors.red,
               foregroundColor: Colors.white,
@@ -569,15 +575,15 @@ class _ThemeManagementScreenState extends State<ThemeManagementScreen>
     if (confirmed == true) {
       try {
         await _themeService.deleteCustomTheme(theme.id);
-        if (!context.mounted) return;
-        ScaffoldMessenger.of(context).showSnackBar(
+        if (!mounted) return;
+        messenger.showSnackBar(
           SnackBar(
             content: Text('主题"${theme.name}"已删除'),
             backgroundColor: Colors.orange,
           ),
         );
       } catch (e) {
-        ScaffoldMessenger.of(context).showSnackBar(
+        messenger.showSnackBar(
           SnackBar(
             content: Text('删除失败: $e'),
             backgroundColor: Colors.red,
@@ -588,18 +594,19 @@ class _ThemeManagementScreenState extends State<ThemeManagementScreen>
   }
 
   Future<void> _importFromClipboard() async {
+    final messenger = ScaffoldMessenger.of(context);
     try {
       final theme = await _themeService.importThemeFromClipboard();
-      if (!context.mounted) return;
+      if (!mounted) return;
       if (theme != null) {
-        ScaffoldMessenger.of(context).showSnackBar(
+        messenger.showSnackBar(
           SnackBar(
             content: Text('主题"${theme.name}"导入成功'),
             backgroundColor: Colors.green,
           ),
         );
       } else {
-        ScaffoldMessenger.of(context).showSnackBar(
+        messenger.showSnackBar(
           const SnackBar(
             content: Text('剪贴板中没有找到有效的主题数据'),
             backgroundColor: Colors.orange,
@@ -607,7 +614,7 @@ class _ThemeManagementScreenState extends State<ThemeManagementScreen>
         );
       }
     } catch (e) {
-      ScaffoldMessenger.of(context).showSnackBar(
+      messenger.showSnackBar(
         SnackBar(
           content: Text('导入失败: $e'),
           backgroundColor: Colors.red,
@@ -664,6 +671,7 @@ class _ThemeManagementScreenState extends State<ThemeManagementScreen>
   }
 
   Future<void> _importTheme(String input) async {
+    final messenger = ScaffoldMessenger.of(context);
     try {
       models.CustomThemeData theme;
 
@@ -673,17 +681,17 @@ class _ThemeManagementScreenState extends State<ThemeManagementScreen>
       } else {
         // 从分享码导入
         theme = await _themeService.importSharedTheme(input);
-        if (!context.mounted) return;
+        if (!mounted) return;
       }
 
-      ScaffoldMessenger.of(context).showSnackBar(
+      messenger.showSnackBar(
         SnackBar(
           content: Text('主题"${theme.name}"导入成功'),
           backgroundColor: Colors.green,
         ),
       );
     } catch (e) {
-      ScaffoldMessenger.of(context).showSnackBar(
+      messenger.showSnackBar(
         SnackBar(
           content: Text('导入失败: $e'),
           backgroundColor: Colors.red,
@@ -693,6 +701,10 @@ class _ThemeManagementScreenState extends State<ThemeManagementScreen>
   }
 
   Future<void> _resetToDefault() async {
+    final navigator = Navigator.of(context);
+    final messenger = ScaffoldMessenger.of(context);
+    final navigator = Navigator.of(context);
+    final messenger = ScaffoldMessenger.of(context);
     final confirmed = await showDialog<bool>(
       context: context,
       builder: (context) => AlertDialog(
@@ -700,11 +712,11 @@ class _ThemeManagementScreenState extends State<ThemeManagementScreen>
         content: const Text('确定要重置为系统默认主题吗？'),
         actions: [
           TextButton(
-            onPressed: () => Navigator.of(context).pop(false),
+            onPressed: () => navigator.pop(false),
             child: const Text('取消'),
           ),
           ElevatedButton(
-            onPressed: () => Navigator.of(context).pop(true),
+            onPressed: () => navigator.pop(true),
             style: ElevatedButton.styleFrom(
               backgroundColor: Colors.black,
               foregroundColor: Colors.white,
@@ -717,8 +729,8 @@ class _ThemeManagementScreenState extends State<ThemeManagementScreen>
 
     if (confirmed == true) {
       await _themeService.resetToSystemTheme();
-      if (!context.mounted) return;
-      ScaffoldMessenger.of(context).showSnackBar(
+      if (!mounted) return;
+      messenger.showSnackBar(
         const SnackBar(
           content: Text('已重置为系统默认主题'),
           backgroundColor: Colors.green,