Flutter学习之创建一个内嵌的navigation详解

class HomePage extends StatelessWidget {
  const HomePage({
    super.key,
  });

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: _buildAppBar(context),
      body: Center(
        child: Padding(
          padding: const EdgeInsets.symmetric(horizontal: 24.0),
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: const [
              SizedBox(
                width: 250,
                height: 250,
                child: Center(
                  child: Icon(
                    Icons.home,
                    size: 175,
                    color: Colors.blue,
                  ),
                ),
              ),
              SizedBox(height: 32),
              Text(
                '跳转到好友匹配页面',
                textAlign: TextAlign.center,
                style: TextStyle(
                  fontSize: 24,
                  fontWeight: FontWeight.bold,
                ),
              ),
            ],
          ),
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () {
          Navigator.of(context).pushNamed(routeFriendMatch);
        },
        child: const Icon(Icons.add),
      ),
    );
  }

class SettingsPage extends StatelessWidget {
  const SettingsPage({
    super.key,
  });

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: _buildAppBar(),
      body: SingleChildScrollView(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: List.generate(8, (index) {
            return  ListTile(
              title: Text('设置项$index'),
            );
          }),
        ),
      ),
    );
  }

void main() {
  runApp(
    MaterialApp(
      onGenerateRoute: (settings) {
        late Widget page;
        if (settings.name == routeHome) {
          page = const HomePage();
        } else if (settings.name == routeSettings) {
          page = const SettingsPage();
        } else if (settings.name == routeFriendMatch) {
          page = const FriendMatchFlow(
            setupPageRoute: routeFriendMatchPage,
          );
        }

        return MaterialPageRoute<dynamic>(
          builder: (context) {
            return page;
          },
          settings: settings,
        );
      },
      debugShowCheckedModeBanner: false,
    ),
  );
}

  Widget build(BuildContext context) {
    return WillPopScope(
      onWillPop: _isExitDesired,
      child: Scaffold(
        appBar: _buildFlowAppBar(),
        body: Navigator(
          key: _navigatorKey,
          initialRoute: widget.setupPageRoute,
          onGenerateRoute: _onGenerateRoute,
        ),
      ),
    );
  }

  final _navigatorKey = GlobalKey<NavigatorState>();

  Route _onGenerateRoute(RouteSettings settings) {
    late Widget page;
    switch (settings.name) {
      case routeFriendMatchPage:
        page = WaitingPage(
          message: '匹配附近的好友...',
          onWaitComplete: _onDiscoveryComplete,
        );
        break;
      case routeFriendSelectPage:
        page = SelectFriendPage(
          onFriendSelected: _onFriendSelected,
        );
        break;
      case routeFriendConnectingPage:
        page = WaitingPage(
          message: '匹配中...',
          onWaitComplete: _onConnectionEstablished,
        );
        break;
      case routeFriendFinishedPage:
        page = FinishedPage(
          onFinishPressed: _exitSetup,
        );
        break;
    }

  void _onDiscoveryComplete() {
    _navigatorKey.currentState!.pushNamed(routeFriendSelectPage);
  }

  void _onFriendSelected(String deviceId) {
    _navigatorKey.currentState!.pushNamed(routeFriendConnectingPage);
  }

  void _onConnectionEstablished() {
    _navigatorKey.currentState!.pushNamed(routeFriendFinishedPage);
  }

  void _exitSetup() {
    Navigator.of(context).pop();
  }