二次开发源码提交

lib/presentation/providers/navigation_provider.dart

@@ -0,0 +1,14 @@
+import 'package:flutter/foundation.dart';
+
+class NavigationProvider extends ChangeNotifier {
+  int _currentIndex = 0; // 默认概览页
+
+  int get currentIndex => _currentIndex;
+
+  void setIndex(int index) {
+    if (_currentIndex != index) {
+      _currentIndex = index;
+      notifyListeners();
+    }
+  }
+}