Flutter Firebase auth 用户在设备上不是持久的

Posted 2023-02-23

【中文标题】Flutter Firebase auth 用户在设备上不是持久的

【英文标题】：Flutter Firebase auth user is not persistent on the device

【发布时间】：2020-11-29 06:57:06

【问题描述】：

我在我的安卓 Flutter 应用程序中使用了 Firebase 手机身份验证。登录系统正常工作。但是，每次我打开应用程序时，它都会返回 null 用户。因此，我每次打开应用程序时都必须登录。我不知道这是我的错误还是错误，但我会在这里与你们分享代码。

电话验证码：

enum PhoneAuthStatus 
  SignedIn,
  CodeSent,
  HasError,
  SignedOut,



class PhoneAuth with ChangeNotifier 
  String verificationId;
  final FirebaseAuth phoneAuth = FirebaseAuth.instance;
  PhoneAuthStatus phoneAuthStatus = PhoneAuthStatus.SignedOut;

  PhoneAuth.initialize() 
    init();
  

  Future<void> init() async 
    currentUser = await phoneAuth.currentUser();
    if (currentUser == null) 
      phoneAuthStatus = PhoneAuthStatus.SignedOut;
      notifyListeners();
     else 
      phoneAuthStatus = PhoneAuthStatus.SignedIn;
    
  

  PhoneAuthStatus get status => phoneAuthStatus;
  FirebaseUser get user => currentUser;

  Future<void> verifyPhoneNumber(String phNum) async 
    phoneAuth.verifyPhoneNumber(
        phoneNumber: phNum,
        timeout: Duration(seconds: 90),
        verificationCompleted: (AuthCredential phoneAuthCredential) async 
          AuthResult authResult;
          try 
            authResult =
                await phoneAuth.signInWithCredential(phoneAuthCredential);
           catch (error) 
            phoneAuthStatus = PhoneAuthStatus.HasError;
            notifyListeners();
            return;
          
          currentUser = authResult.user;
          uid = currentUser.uid;
          phoneAuthStatus = PhoneAuthStatus.SignedIn;
          notifyListeners();
        ,
        verificationFailed: (AuthException authException) 
          print(authException.message);
          phoneAuthStatus = (PhoneAuthStatus.HasError);
          notifyListeners();
        ,
        codeSent: (String vId, [int forceResendingToken]) async 
          phoneAuthStatus = (PhoneAuthStatus.CodeSent);
          notifyListeners();
          verificationId = vId;
        ,
        codeAutoRetrievalTimeout: (String vId) 
          verificationId = vId;
        );
    return;
  

  Future<void> signInWithPhoneNumber(String code) async 
    final AuthCredential credential = PhoneAuthProvider.getCredential(
      verificationId: verificationId,
      smsCode: code.toString(),
    );
    AuthResult authResult;
    try 
      authResult = await phoneAuth.signInWithCredential(credential);
     catch (error) 
      phoneAuthStatus = (PhoneAuthStatus.HasError);
      notifyListeners();
      return;
    
    currentUser = authResult.user;
    phoneAuthStatus = (PhoneAuthStatus.SignedIn);
    notifyListeners();
    return;
  

  Future<void> signOut() async 
    phoneAuth.signOut();
    phoneAuthStatus = (PhoneAuthStatus.SignedOut);
    notifyListeners();
  

main.dart 代码：

class MyApp extends StatelessWidget 
  @override
  Widget build(BuildContext context) 
    return MultiProvider(
      providers: [
        ChangeNotifierProvider.value(value: PhoneAuth.initialize()),
      ],
      child: MaterialApp(
        title: app_name,
        // routes: Routes.routes,
        debugShowCheckedModeBanner: false,
        theme: ThemeData(
            primarySwatch: Colors.blue,
        )
        home: Container(
          child: LocationError(currentWidget: HomePage()),
        ),
      ),
    );
  

init() 函数应该返回 PhoneAuthStatus.SignedIn。但是，它返回 PhoneAuthStatus.SignedOut，因为 currentUser 为空。 如果我做错了什么，请帮助我并告诉我。谢谢。

颤振医生：

Doctor summary (to see all details, run flutter doctor -v):
[√] Flutter (Channel stable, 1.20.0, on Microsoft Windows [Version 10.0.18363.959], locale en-US)
 
[!] android toolchain - develop for Android devices (Android SDK version 29.0.2)
    X Android license status unknown.
      Try re-installing or updating your Android SDK Manager.
      See https://developer.android.com/studio/#downloads or visit https://flutter.dev/docs/get-started/install/windows#android-setup for detailed instructions.
[√] Android Studio (version 4.0)
[√] VS Code (version 1.47.3)
[!] Connected device
    ! No devices available

! Doctor found issues in 2 categories.

【参考方案1】：

您是否检查过将 notifyListeners() 放在 if 块之外？

     currentUser = await phoneAuth.currentUser();
    if (currentUser == null) 
      phoneAuthStatus = PhoneAuthStatus.SignedOut;
     
     else 
      phoneAuthStatus = PhoneAuthStatus.SignedIn;
    
 notifyListeners();

另一个猜测是，您在 init() 方法中调用未来方法。也许这就是为什么您总是将身份验证状态设为 signOut。

“init 方法在设计上是同步的。您可以在重写的 build 方法中返回 FutureBuilder 小部件，而不是在 init 方法中创建 FutureBuilder 小部件。感觉在这里免费查看 FutureBuilder 小部件的文档，以获取有关其工作原理的示例。”

所以，我认为最好使用未来的构建器来验证用户的存在。

【讨论】：

我已经正确使用了 notifyListeners()。我将在 FutureBuilder 中尝试并让您知道。谢谢。