Flutter 中的 Navigator pushReplacement 错误

Question

导航到下一页后，我的启动画面出现问题

class SplashScreen extends StatelessWidget {
  final backgroundColor = 0xffF6F6F6;

  @override
  Widget build(BuildContext context) {
    Future.delayed(const Duration(seconds: 3), () {
      Navigator.of(context).pushReplacement(
        MaterialPageRoute(
          builder: (context) => Wrapper(),
        ),
      );
    });

    return ScreenUtilInit(
      builder: () => MaterialApp(...),
    );
  }
}

简单的 'Navigator.of(context).push' 工作正常，没有显示但使用 pushReplacement 下一个错误显示：

D/NetworkSecurityConfig( 8102): No Network Security Config specified, using platform default
W/System  ( 8102): Ignoring header X-Firebase-Locale because its value was null.
W/DynamiteModule( 8102): Local module descriptor class for providerinstaller not found.
I/DynamiteModule( 8102): Considering local module providerinstaller:0 and remote module providerinstaller:0
W/ProviderInstaller( 8102): Failed to load providerinstaller module: No acceptable module found. Local version is 0 and remote version is 0.
I/com.my_app( 8102): The ClassLoaderContext is a special shared library.
I/chatty  ( 8102): uid=10088(com.my_app) AsyncTask #2 identical 1 line
I/com.my_app( 8102): The ClassLoaderContext is a special shared library.
V/NativeCrypto( 8102): Registering com/google/android/gms/org/conscrypt/NativeCrypto's 294 native methods...
W/com.my_app( 8102): Accessing hidden method Ljava/security/spec/ECParameterSpec;->getCurveName()Ljava/lang/String; (light greylist, reflection)
I/ProviderInstaller( 8102): Installed default security provider GmsCore_OpenSSL
W/com.my_app( 8102): Accessing hidden method Ljava/security/spec/ECParameterSpec;->setCurveName(Ljava/lang/String;)V (light greylist, reflection)
D/FirebaseAuth( 8102): Notifying id token listeners about user ( sXisKRx15aeLiT7rGR8XS4yGGNJ2 ).
E/flutter ( 8102): [ERROR:flutter/shell/common/shell.cc(93)] Dart Unhandled Exception: Looking up a deactivated widget's ancestor is unsafe.
E/flutter ( 8102): At this point the state of the widget's element tree is no longer stable.
E/flutter ( 8102): To safely refer to a widget's ancestor in its dispose() method, save a reference to the ancestor by calling dependOnInheritedWidgetOfExactType() in the widget's didChangeDependencies() method., stack trace: #0      Element._debugCheckStateIsActiveForAncestorLookup.<anonymous closure> (package:flutter/src/widgets/framework.dart:4032:9)
E/flutter ( 8102): #1      Element._debugCheckStateIsActiveForAncestorLookup (package:flutter/src/widgets/framework.dart:4046:6)
E/flutter ( 8102): #2      Element.findAncestorStateOfType (package:flutter/src/widgets/framework.dart:4093:12)
E/flutter ( 8102): #3      Navigator.of (package:flutter/src/widgets/navigator.dart:2736:40)
E/flutter ( 8102): #4      SplashScreen.build.<anonymous closure> (package:first_project_test/screens/home/splash.dart:13:17)
E/flutter ( 8102): #5      new Future.delayed.<anonymous closure> (dart:async/future.dart:315:39)
E/flutter ( 8102): #6      Timer._createTimer.<anonymous closure> (dart:async-patch/timer_patch.dart:18:15)
E/flutter ( 8102): #7      _Timer._runTimers (dart:isolate-patch/timer_impl.dart:395:19)
E/flutter ( 8102): #8      _Timer._handleMessage (dart:isolate-patch/timer_impl.dart:426:5)
E/flutter ( 8102): #9      _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:184:12)

它仅在我使用“Run 'main.dart'”重新渲染页面时显示，我用 ScreenUtilInit 包装了 Material 应用程序，因为

我还在我的主文件中使用 InitializerWidget 类运行 SplashScreen，如果您需要有关它的更多信息，请告诉我❤

Answer 1

我们不应该直接调用build方法中的函数。
当一个逻辑只需要在创建 Widget 的状态时实现一次时，就使用initState h。

1. 将Stateless Stateful更改为Stateful

class SplashScreen extends StatefulWidget {
 const SplashScreen({Key? key}) : super(key: key);

 @override
 _SplashScreenState createState() => _SplashScreenState();
}

class _SplashScreenState extends State<SplashScreen> {
 
 @override
 Widget build(BuildContext context) {
   return SomeWidget();
 }

}

2. 现在将所需的逻辑放在initState方法中。

class _SplashScreenState extends State<SplashScreen> {
  
  @override
  initState() {
    super.initState();

    Future.delayed(const Duration(seconds: 3), () {
      Navigator.of(context).pushReplacement(
        MaterialPageRoute(
          builder: (context) => Wrapper(),
        ),
      );
    });
  }

// other methods 

}