feat: rewrite SettingsPage with save and test-connection

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

lib/pages/settings_page.dart

@@ -13,6 +13,7 @@ class _SettingsPageState extends State<SettingsPage> {
   final _controller = TextEditingController();
   final _apiService = ApiService();
   bool _saving = false;
+  bool _testing = false;
 
   @override
   void initState() {
@@ -22,41 +23,52 @@ class _SettingsPageState extends State<SettingsPage> {
 
   Future<void> _loadUrl() async {
     final prefs = await SharedPreferences.getInstance();
-    _controller.text = prefs.getString('api_url') ?? '';
+    final url = prefs.getString('api_url') ?? '';
+    _controller.text = url;
   }
 
   Future<void> _saveUrl() async {
+    final url = _controller.text.trim();
+    if (url.isEmpty) {
+      _showSnackBar('请输入 API 地址', isError: true);
+      return;
+    }
     setState(() => _saving = true);
     final prefs = await SharedPreferences.getInstance();
-    await prefs.setString('api_url', _controller.text.trim());
+    await prefs.setString('api_url', url);
     setState(() => _saving = false);
     if (mounted) {
-      ScaffoldMessenger.of(context).showSnackBar(
-        const SnackBar(content: Text('URL saved')),
-      );
+      _showSnackBar('设置已保存');
     }
   }
 
   Future<void> _testConnection() async {
     final url = _controller.text.trim();
     if (url.isEmpty) {
-      ScaffoldMessenger.of(context).showSnackBar(
-        const SnackBar(content: Text('Please enter a URL first')),
-      );
+      _showSnackBar('请先输入 API 地址', isError: true);
       return;
     }
-    final ok = await _apiService.sendScanData(
-      url,
-      barcode: 'TEST_BARCODE',
-      codeType: 'TEST',
-    );
+    setState(() => _testing = true);
+    final ok = await _apiService.testConnection(url);
+    setState(() => _testing = false);
     if (mounted) {
-      ScaffoldMessenger.of(context).showSnackBar(
-        SnackBar(content: Text(ok ? 'Connection OK' : 'Connection failed')),
+      _showSnackBar(
+        ok ? '连接成功' : '连接失败，请检查地址和网络',
+        isError: !ok,
       );
     }
   }
 
+  void _showSnackBar(String message, {bool isError = false}) {
+    ScaffoldMessenger.of(context).showSnackBar(
+      SnackBar(
+        content: Text(message),
+        backgroundColor: isError ? Colors.red.shade700 : Colors.green.shade700,
+        duration: const Duration(seconds: 2),
+      ),
+    );
+  }
+
   @override
   void dispose() {
     _controller.dispose();
@@ -66,35 +78,45 @@ class _SettingsPageState extends State<SettingsPage> {
   @override
   Widget build(BuildContext context) {
     return Scaffold(
-      appBar: AppBar(title: const Text('Settings')),
+      appBar: AppBar(title: const Text('设置')),
       body: Padding(
         padding: const EdgeInsets.all(16),
         child: Column(
           crossAxisAlignment: CrossAxisAlignment.stretch,
           children: [
+            const Text('API 服务器地址', style: TextStyle(fontSize: 14)),
+            const SizedBox(height: 8),
             TextField(
               controller: _controller,
               decoration: const InputDecoration(
-                labelText: 'API URL',
-                hintText: 'http://192.168.1.100:8000/scan',
+                hintText: 'http://192.168.1.100:8000',
                 border: OutlineInputBorder(),
               ),
               keyboardType: TextInputType.url,
             ),
-            const SizedBox(height: 16),
-            ElevatedButton(
+            const SizedBox(height: 20),
+            ElevatedButton.icon(
               onPressed: _saving ? null : _saveUrl,
-              child: _saving
+              icon: _saving
                   ? const SizedBox(
-                      width: 20,
-                      height: 20,
-                      child: CircularProgressIndicator(strokeWidth: 2))
-                  : const Text('Save'),
+                      width: 18,
+                      height: 18,
+                      child: CircularProgressIndicator(strokeWidth: 2),
+                    )
+                  : const Icon(Icons.save),
+              label: const Text('保存设置'),
             ),
             const SizedBox(height: 8),
-            OutlinedButton(
-              onPressed: _testConnection,
-              child: const Text('Test Connection'),
+            OutlinedButton.icon(
+              onPressed: _testing ? null : _testConnection,
+              icon: _testing
+                  ? const SizedBox(
+                      width: 18,
+                      height: 18,
+                      child: CircularProgressIndicator(strokeWidth: 2),
+                    )
+                  : const Icon(Icons.wifi),
+              label: const Text('测试连接'),
             ),
           ],
         ),