Question

例如，我有以下伪代码：

if(state1.status==ok&&state2.status==ok) {do something}

MultiBlocListener在这里不适用，因为我只能分别监听状态，我尝试嵌套BlocListener，但它并没有帮助我，因为外部BlocListener不会通知内部状态更改。所以在内部，只有在内部状态改变的那一刻，我才能检查外部的状态。

目前，我通过使用嵌套的BlocBuilder和WidgetsBinding.instance.addPostFrameCallback解决了这个问题。在这种情况下，外部BlocBuilder会重建内部class SplashScreen extends StatefulWidget { static const routeName = 'splash'; static const logoUrl = 'assets/images/logo.svg'; const SplashScreen({Key key}) : super(key: key); @override _SplashScreenState createState() => _SplashScreenState(); } class _SplashScreenState extends State<SplashScreen> { @override Widget build(BuildContext context) { void _navigateTo(String routeName) => Navigator.of(context).pushReplacementNamed(routeName); return Scaffold( backgroundColor: Theme.of(context).backgroundColor, body: BlocBuilder<SettingsBloc, SettingsState>( builder: (context, settingsState) { return BlocBuilder<AuthenticationBloc, AuthenticationState>( builder: (context, authenticationState) { WidgetsBinding.instance.addPostFrameCallback((_) { if (authenticationState.status == AuthenticationStatus.UNAUTHENTICATED) { Timer(Duration(seconds: 1), () => _navigateTo(LoginScreen.routeName)); } else if (authenticationState.status == AuthenticationStatus.AUTHENTICATED) { switch (settingsState.currentType) { case FastAccessType.UNKNOWN: break; case FastAccessType.NONE: Timer(Duration(seconds: 1), () => _navigateTo(HomeScreen.routeName)); break; case FastAccessType.PIN: Timer(Duration(seconds: 1), () => _navigateTo(PinCodeScreen.routeNameLogin)); break; case FastAccessType.BIOMETRICS: Timer(Duration(seconds: 1), () => _navigateTo(BiometricsScreen.routeName)); break; } } }); return Container( decoration: BoxDecoration(gradient: mainGradient), child: Center( child: WebsafeSvg.asset(SplashScreen.logoUrl), ), ); }, ); }, ), ); } }，我可以检查多个状态更改是否正确。但我不确定通常是否可以通过这种方式解决此问题。

注意：状态1来自bloc1，状态2来自bloc2，换句话说，来自多个集团的多个状态

这是我现在使用的代码：

{{1}}

当我在设备导航测试中看到两次调用该动画时，它看起来并不干净。

Answer 1

尝试条件

          BlocBuilder<BlocT, YourState>(
            bloc: bloc,
            condition: (c, s) => (s is ValidationState ),

如何在带有bloc_library的BlocListener中使用多个状态？

1 个答案: