显然，最近的一些Android版本已经足够智能，可以接收短信验证码并使用它来认证用户。这种认证在后台进行，而**用户仍然在短信中接收验证码。当用户尝试输入验证码时，他/她会收到一条消息，表明验证码已过期，因为Android已经使用了它（在后台），并且已经登录了用户！要仔细检查，请检查Firebase控制台。您应该会发现此新用户已添加到用户列表中。
为了避免收到验证码过期消息，我们需要设置一个身份验证更改监听器。当Android后台登录用户时，这个监听器应该引导用户离开登录界面，用户应该在登录界面输入验证码。下面演示了如何实现这一点。我将在登录界面添加以下代码。
用于功能组件的示例代码：

useEffect( () => {
    firebase.auth().onAuthStateChanged( (user) => {
        if (user) {
            // Obviously, you can add more statements here, 
            //       e.g. call an action creator if you use Redux. 

            // navigate the user away from the login screens: 
            props.navigation.navigate("PermissionsScreen");
        } 
        else 
        {
            // reset state if you need to  
            dispatch({ type: "reset_user" });
        }
    });
}, []);

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用于类组件的示例代码：

// I did NOT test this version, because I use functional components. 
componentDidMount() {
    firebase.auth().onAuthStateChanged( (user) => {
        if (user) {
            // Obviously, you can add more statements here, 
            //       e.g. call an action creator if you use Redux. 

            // navigate the user away from the login screens: 
            props.navigation.navigate("PermissionsScreen");
        } 
        else 
        {
            // reset state if you need to 
            this.setState({
                user: null,
                messageText: '',
                codeInput: '',
                phoneNo: '',
                confirmResult: null,
            });
        }
    });
};

型

您需要使用以下方法检查后台身份验证：

conponentDidMount() {    
firebase.auth().onAuthStateChanged((user) => {
            if (user) {
                // alert(JSON.stringify(user))
                // Obviously, you can add more statements here, 
                //       e.g. call an action creator if you use Redux. 
                // navigate the user away from the login screens: 
            }
        });
}

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然后，您需要注销您的用户，一旦你完成了它（我面临着这个问题的旧用户会话已经存在，而新用户来验证）
因此，在注销时用途：

if (firebase.auth().currentUser)
            firebase.auth().currentUser.delete();

型
一切都准备好了！

我发现问题是上述（Android试图在后台自动处理）.我发现的解决方案是将一个监听内的方法，验证phoneSignin.见下文：

Future<void> createUserWithPhone(
  {required String phoneNumber,
  required BuildContext context,
  required Function(bool esteEumNovoUser) verifyCompleted,
  required Function(String erroMsg) failed,
  required Function(String generatedCodeId) codeSent,
  required VoidCallback codeRetrieveTimeout}) async {
FirebaseAuth auth = FirebaseAuth.instance;

//create a listener that will handle the signing
var listener = FirebaseAuth.instance.authStateChanges();
//place the listener to handle the login and the automatic login in 
 background
listener.listen((User? user) {
  if (user != null) {
    debugPrint('logged in');
    final DateTime? dataCriacao = user.metadata.creationTime;
    final DateTime dataAgora = DateTime.now();

    if (dataCriacao != null) {
      debugPrint(dataCriacao.toString());
      final Duration difference = dataAgora.difference(dataCriacao);
      final int minutesDifference = difference.inMinutes;
      //if difference is short, we know its a new user
      if (minutesDifference <= 3) {
       
         newUserCreated(); //now you proceed with your code, probably 
          //creating a new entry in Firestore
         //verifyCompleted(true) in My code I use this callback
        listener.listen((event) {}).cancel();

      } else {
        
        existingUserLoggin();//was a existing user, handle the result
        //verifyCompleted(false) in My code I use this callback
        listener.listen((event) {}).cancel();
   
      }
    } else {
      debugPrint('novo user');
      newUserCreated(); //if no datacreation available, its a new user
      //verifyCompleted(true) in My code I use this callback
      listener.listen((event) {}).cancel();

    }
  } else {
    debugPrint('not logged in, do nothing');
  }
});

//keep the phoneLogin logic of firebase to create the user in backend for 
//you
await auth.verifyPhoneNumber(
  timeout: const Duration(seconds: 60),
  phoneNumber: '+55$phoneNumber',
  verificationCompleted: (PhoneAuthCredential credential) {
    debugPrint(credential.toString());
    debugPrint('Verificação completa');

    //Disconsider this block of code bellow, you are now handling it
    //on listener above.
    // ANDROID ONLY!
    // Sign the user in (or link) with the auto-generated credential
    /*
    signInWithPhone(
        credential: credential,
        createUser: () {
          verifyCompleted(true);
        },
        signinThisUser: () {
          verifyCompleted(false);
        });*/
  },
  verificationFailed: (FirebaseAuthException e) {
    debugPrint('failed');
    debugPrint(e.message);
    debugPrint(e.code);
    debugPrint(e.toString());
    if (e.code == 'invalid-phone-number') {
      failed('Você informou um número inválido');
    } else {
      failed('Ocorreu um erro. Tente novamente em instantes');
    }
  },
  codeSent: (String verificationId, int? resendToken) {
    debugPrint('code sent');
    debugPrint(verificationId);

    codeSent(verificationId);
  },
  codeAutoRetrievalTimeout: (String verificationId) {
    debugPrint('acabou o tempo de timedout');
    MySnack().displaySnackBar(context, 'entrou em 
    codeAutoRetrievalTimeout');
    codeRetrieveTimeout();
    },
   );
 }

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