111

flutter_monisuo/lib/ui/pages/main/main_page.dart

@@ -27,18 +27,23 @@ class MainPage extends StatefulWidget {
   State<MainPage> createState() => MainPageState();
 }
 
-class MainPageState extends State<MainPage> {
+class MainPageState extends State<MainPage> with WidgetsBindingObserver {
   int _currentIndex = 0;
   final Set<int> _loadedPages = {0};
   String? _tradeCoinCode; // 交易頁面選中的幣種代碼
   late final List<Widget> _pages;
+  bool _isAppVisible = true;
 
   // 防抖：記錄上次刷新時間，同一 Tab 500ms 內不重複刷新
   final Map<int, DateTime> _lastRefreshTime = {};
 
+  /// 当前页面是否可见（供子页面判断是否需要轮询）
+  bool isPageVisible(int pageIndex) => _currentIndex == pageIndex && _isAppVisible;
+
   @override
   void initState() {
     super.initState();
+    WidgetsBinding.instance.addObserver(this);
     _pages = [
       const HomePage(),
       const MarketPage(),
@@ -48,6 +53,17 @@ class MainPageState extends State<MainPage> {
     ];
   }
 
+  @override
+  void dispose() {
+    WidgetsBinding.instance.removeObserver(this);
+    super.dispose();
+  }
+
+  @override
+  void didChangeAppLifecycleState(AppLifecycleState state) {
+    _isAppVisible = state == AppLifecycleState.resumed;
+  }
+
   void _onTabChanged(int index) {
     final wasLoaded = _loadedPages.contains(index);
     setState(() {