材料app重建当家庭小部件调用构建功能时

Question

我的应用程序的myApp窗口小部件，返回材料应用（几乎在每个flutter应用程序中完成），每当home> home> home widget称为build>时，都会重新构建。我需要知道为什么会发生这种情况，因为它大大降低了我的应用程序的性能。

我使用StreamProvider（ riverpod 主页，landingpage或加载屏幕（出于历史原因，pseudosplashscreen），具体取决于用户是否登录，还是流等待。

我的main.dart包含，除其他外：

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  FirebaseMessaging.instance.unsubscribeFromTopic('allUsers');

  runApp(const ProviderScope(child: MyApp()));
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    debugPrint("Returning MaterialApp");
    return MaterialApp(
      title: 'MyApp',
      localizationsDelegates: AppLocalizations.localizationsDelegates,
      supportedLocales: AppLocalizations.supportedLocales,
      debugShowCheckedModeBanner: false,
      theme: themeDataLight(),
      darkTheme: themeDataDark(),
      home: const ReDirector(),
    );
  }
}

class ReDirector extends ConsumerWidget {
  const ReDirector({Key? key}) : super(key: key);
  static const LandingPage landingPage = LandingPage();
  static const PseudoSplashScreen pseudoSplashScreen = PseudoSplashScreen();

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    debugPrint("Building Redirector");
    return ref.watch(authStreamProvider).when(
      data: (data) {
        debugPrint(data.toString());
        if (data != null && data == AuthResultStatus.successful) {
          debugPrint("Returning Homepage");
          return Container(
            width: double.infinity,
            height: double.infinity,
            color: Colors.blue,
          );
        } else {
          debugPrint("AuthStreamProvider returned $data");
          // When logging in, it is set to true. Hence, set it to false to prevent
          // the isInAsync overlay from showing when logging out.
          ref.read(landingPageProvider).isInAsync = false;
          return landingPage;
        }
      },
      error: (e, tb) {
        debugPrint("Error in the AuthChecker");
        debugPrint("$e\n$tb");
        // When logging in, it is set to true. Hence, set it to false to prevent
        // the isInAsync overlay from showing on error
        ref.read(landingPageProvider).isInAsync = false;
        return landingPage;
      },
      loading: () {
        debugPrint("Returning PseudoSplashScreen");
        return pseudoSplashScreen;
      },
    );
  }
}

流是从firebaseauth.instance.authstatatechanges，但已扩展以检查用户上的一些额外详细信息：

final authStreamProvider = StreamProvider.autoDispose<AuthResultStatus?>((ref) {
  return FirebaseAuth.instance
      .authStateChanges()
      .asyncExpand((User? user) async* {
        AuthResultStatus? result;
    if (user != null) {
      final IdTokenResult idTokenResult = await user.getIdTokenResult();
      if (user.emailVerified && idTokenResult.claims!['approved'] == true) {
        ref.read(userDataProvider).initialize(user, idTokenResult.claims!);
        result = AuthResultStatus.successful;
      } else {
        result = AuthResultStatus.undefined;
      }
    }
    debugPrint("AuthStreamProvider is yielding $result");
    yield result;
  });
});

where > AuthResultStatus是枚举。现在，我希望在流量加载时，显示了伪PlaSplashScreen，并且当流触发authresultStatus.successful时，显示了homepage。确实发生了什么，但是以某种方式我的redirector在显示主页后大约一秒钟重建。实际上，再次调用myApp的构建函数！关于代码中的调试打印机，控制台显示了以下内容：

I/flutter (22428): Returning MaterialApp
I/flutter (22428): Building Redirector
I/flutter (22428): Returning PseudoSplashScreen
I/flutter (22428): Creating new userdatamodel
I/flutter (22428): CURRENTUSER: Wessel van Dam
I/flutter (22428): AuthStreamProvider is yielding AuthResultStatus.successful
I/flutter (22428): Building Redirector
I/flutter (22428): AuthResultStatus.successful
I/flutter (22428): Returning Homepage
I/flutter (22428): Returning MaterialApp
I/flutter (22428): Building Redirector
I/flutter (22428): AuthResultStatus.successful
I/flutter (22428): Returning Homepage

请注意，重建导演的重建不是由于流的新射击事件引起的，因为那时您会期望返回成功的ARS的另一幅印刷品。但是，重建重建导演非常烦人，因为构建主页是一个非常激烈的过程。这种重建会导致屏幕闪烁。谁能告诉我为什么在此序列中再次调用重定向器的构建功能？如果可以防止这种情况，我的应用程序的用户体验将得到很大改善。