Na guia Método de login, ative o método de login do Google e clique em Salvar.
Quando aparecer a solicitação no console, faça o download do arquivo de configuração atualizado do Firebase
(google-services.json), que agora contém as informações do cliente OAuth
necessárias para o login do Google.
Mova esse arquivo de configuração atualizado para seu projeto do Android Studio substituindo
o arquivo de configuração correspondente desatualizado.
(Consulte Adicionar o Firebase ao projeto do Android).
Acessar a classe firebase::auth::Auth
A classe Auth é o gateway para todas as chamadas de API.
Adicione os arquivos de cabeçalho Auth e App:
#include"firebase/app.h"#include"firebase/auth.h"
No código de inicialização, crie uma
classe firebase::App.
Se seu programa tiver uma rotina de atualização regular, por exemplo, 30 ou 60
vezes por segundo, será possível verificar os resultados uma vez por ciclo usando
Auth::SignInAndRetrieveDataWithCredentialLastResult:
firebase::Future<firebase::auth::AuthResult>result=auth->SignInAndRetrieveDataWithCredentialLastResult();if(result.status()==firebase::kFutureStatusComplete){if(result.error()==firebase::auth::kAuthErrorNone){firebase::auth::AuthResultauth_result=*result.result();printf("Sign in succeeded for `%s`\n",auth_result.user.display_name().c_str());}else{printf("Sign in failed with error '%s'\n",result.error_message());}}
Registrar um retorno de chamada em uma classe Future
Alguns programas têm função Update que são chamadas 30 ou 60 vezes por segundo.
Muitos jogos, por exemplo, seguem esse modelo. Esses programas podem invocar as funções LastResult para pesquisar chamadas assíncronas.
Caso seu programa seja baseado em eventos, pode ser preferível registrar funções de retorno de chamada.
Essas funções são chamadas na conclusão da classe Future.
voidOnCreateCallback(constfirebase::Future<firebase::auth::User*>&result,void*user_data){// The callback is called when the Future enters the `complete` state.assert(result.status()==firebase::kFutureStatusComplete);// Use `user_data` to pass-in program context, if you like.MyProgramContext*program_context=static_cast<MyProgramContext*>(user_data);// Important to handle both success and failure situations.if(result.error()==firebase::auth::kAuthErrorNone){firebase::auth::User*user=*result.result();printf("Create user succeeded for email %s\n",user->email().c_str());// Perform other actions on User, if you like.firebase::auth::User::UserProfileprofile;profile.display_name=program_context->display_name;user->UpdateUserProfile(profile);}else{printf("Created user failed with error '%s'\n",result.error_message());}}voidCreateUser(firebase::auth::Auth*auth){// Callbacks work the same for any firebase::Future.firebase::Future<firebase::auth::AuthResult>result=auth->CreateUserWithEmailAndPasswordLastResult();// `&my_program_context` is passed verbatim to OnCreateCallback().result.OnCompletion(OnCreateCallback,&my_program_context);}
Se você preferir, a função de retorno de chamada também pode ser um lambda.
voidCreateUserUsingLambda(firebase::auth::Auth*auth){// Callbacks work the same for any firebase::Future.firebase::Future<firebase::auth::AuthResult>result=auth->CreateUserWithEmailAndPasswordLastResult();// The lambda has the same signature as the callback function.result.OnCompletion([](constfirebase::Future<firebase::auth::User*>&result,void*user_data){// `user_data` is the same as &my_program_context, below.// Note that we can't capture this value in the [] because std::function// is not supported by our minimum compiler spec (which is pre C++11).MyProgramContext*program_context=static_cast<MyProgramContext*>(user_data);// Process create user result...(void)program_context;},&my_program_context);}
Próximas etapas
Depois que um usuário faz login pela primeira vez, uma nova conta de usuário é criada e
vinculada às credenciais, que podem ser o número do telefone,
o nome de usuário e a senha ou as informações do provedor de autenticação. Essa nova
conta é armazenada como parte do projeto do Firebase e pode ser usada para identificar
um usuário em todos os apps do projeto, seja qual for o método de login utilizado.
Nos seus apps, use o objeto
firebase::auth::User para receber as informações básicas de perfil do usuário.
firebase::auth::Useruser=auth->current_user();if(user.is_valid()){std::stringname=user.display_name();std::stringemail=user.email();std::stringphoto_url=user.photo_url();// The user's ID, unique to the Firebase project.// Do NOT use this value to authenticate with your backend server,// if you have one. Use firebase::auth::User::Token() instead.std::stringuid=user.uid();}
Nas
Regras de segurançaFirebase Realtime Database e Cloud Storage, você pode
acessar o ID exclusivo do usuário conectado pela variável auth
e usar essas informações para controlar
quais dados um usuário pode acessar.
[[["Fácil de entender","easyToUnderstand","thumb-up"],["Meu problema foi resolvido","solvedMyProblem","thumb-up"],["Outro","otherUp","thumb-up"]],[["Não contém as informações de que eu preciso","missingTheInformationINeed","thumb-down"],["Muito complicado / etapas demais","tooComplicatedTooManySteps","thumb-down"],["Desatualizado","outOfDate","thumb-down"],["Problema na tradução","translationIssue","thumb-down"],["Problema com as amostras / o código","samplesCodeIssue","thumb-down"],["Outro","otherDown","thumb-down"]],["Última atualização 2025-08-29 UTC."],[],[],null,["You can let your users authenticate with Firebase using their Google Accounts by\nintegrating Google Sign-In into your app.\n\nBefore you begin\n\n1. [Add Firebase to your C++ project](/docs/cpp/setup#note_select_platform).\n2. Enable Google as a sign-in method in the Firebase console:\n 1. In the [Firebase console](//console.firebase.google.com/), open the **Auth** section.\n 2. On the **Sign in method** tab, enable the **Google** sign-in method and click **Save**.\n3. When prompted in the console, download the updated Firebase config file (`google-services.json`), which now contains the OAuth client information required for Google sign-in.\n4. Move this updated config file into your Android Studio project, *replacing* the now-outdated corresponding config file. (See [Add Firebase to your Android project](/docs/android/setup#add-config-file).)\n\nAccess the `firebase::auth::Auth` class The `Auth` class is the gateway for all API calls.\n\n1. Add the Auth and App header files: \n\n ```c++\n #include \"firebase/app.h\"\n #include \"firebase/auth.h\"\n ```\n2. In your initialization code, create a [`firebase::App`](/docs/reference/cpp/class/firebase/app) class. \n\n ```c++\n #if defined(__ANDROID__)\n firebase::App* app =\n firebase::App::Create(firebase::AppOptions(), my_jni_env, my_activity);\n #else\n firebase::App* app = firebase::App::Create(firebase::AppOptions());\n #endif // defined(__ANDROID__)\n ```\n3. Acquire the `firebase::auth::Auth` class for your `firebase::App`. There is a one-to-one mapping between `App` and `Auth`. \n\n ```c++\n firebase::auth::Auth* auth = firebase::auth::Auth::GetAuth(app);\n ```\n\nAuthenticate with Firebase\n\n1. Follow instructions for [Android](/docs/auth/android/google-signin#authenticate_with_firebase) and [iOS+](/docs/auth/ios/google-signin#2_implement_google_sign-in) to get an ID token for the Google sign in.\n2. After a user successfully signs in, exchange the ID token for a Firebase credential, and authenticate with Firebase using the Firebase credential: \n\n ```c++\n firebase::auth::Credential credential =\n firebase::auth::GoogleAuthProvider::GetCredential(google_id_token,\n nullptr);\n firebase::Future\u003cfirebase::auth::AuthResult\u003e result =\n auth-\u003eSignInAndRetrieveDataWithCredential(credential);\n ```\n3. If your program has an update loop that runs regularly (say at 30 or 60 times per second), you can check the results once per update with `Auth::SignInAndRetrieveDataWithCredentialLastResult`: \n\n ```c++\n firebase::Future\u003cfirebase::auth::AuthResult\u003e result =\n auth-\u003eSignInAndRetrieveDataWithCredentialLastResult();\n if (result.status() == firebase::kFutureStatusComplete) {\n if (result.error() == firebase::auth::kAuthErrorNone) {\n firebase::auth::AuthResult auth_result = *result.result();\n printf(\"Sign in succeeded for `%s`\\n\",\n auth_result.user.display_name().c_str());\n } else {\n printf(\"Sign in failed with error '%s'\\n\", result.error_message());\n }\n }\n ```\n Or, if your program is event driven, you may prefer to [register a callback on the\n Future](#register_callback_on_future).\n\nRegister a callback on a Future Some programs have `Update` functions that are called 30 or 60 times per second. For example, many games follow this model. These programs can call the `LastResult` functions to poll asynchronous calls. However, if your program is event driven, you may prefer to register callback functions. A callback function is called upon completion of the Future. \n\n```c++\nvoid OnCreateCallback(const firebase::Future\u003cfirebase::auth::User*\u003e& result,\n void* user_data) {\n // The callback is called when the Future enters the `complete` state.\n assert(result.status() == firebase::kFutureStatusComplete);\n\n // Use `user_data` to pass-in program context, if you like.\n MyProgramContext* program_context = static_cast\u003cMyProgramContext*\u003e(user_data);\n\n // Important to handle both success and failure situations.\n if (result.error() == firebase::auth::kAuthErrorNone) {\n firebase::auth::User* user = *result.result();\n printf(\"Create user succeeded for email %s\\n\", user-\u003eemail().c_str());\n\n // Perform other actions on User, if you like.\n firebase::auth::User::UserProfile profile;\n profile.display_name = program_context-\u003edisplay_name;\n user-\u003eUpdateUserProfile(profile);\n\n } else {\n printf(\"Created user failed with error '%s'\\n\", result.error_message());\n }\n}\n\nvoid CreateUser(firebase::auth::Auth* auth) {\n // Callbacks work the same for any firebase::Future.\n firebase::Future\u003cfirebase::auth::AuthResult\u003e result =\n auth-\u003eCreateUserWithEmailAndPasswordLastResult();\n\n // `&my_program_context` is passed verbatim to OnCreateCallback().\n result.OnCompletion(OnCreateCallback, &my_program_context);\n}\n```\nThe callback function can also be a lambda, if you prefer. \n\n```c++\nvoid CreateUserUsingLambda(firebase::auth::Auth* auth) {\n // Callbacks work the same for any firebase::Future.\n firebase::Future\u003cfirebase::auth::AuthResult\u003e result =\n auth-\u003eCreateUserWithEmailAndPasswordLastResult();\n\n // The lambda has the same signature as the callback function.\n result.OnCompletion(\n [](const firebase::Future\u003cfirebase::auth::User*\u003e& result,\n void* user_data) {\n // `user_data` is the same as &my_program_context, below.\n // Note that we can't capture this value in the [] because std::function\n // is not supported by our minimum compiler spec (which is pre C++11).\n MyProgramContext* program_context =\n static_cast\u003cMyProgramContext*\u003e(user_data);\n\n // Process create user result...\n (void)program_context;\n },\n &my_program_context);\n}\n```\n\nNext steps\n\nAfter a user signs in for the first time, a new user account is created and\nlinked to the credentials---that is, the user name and password, phone\nnumber, or auth provider information---the user signed in with. This new\naccount is stored as part of your Firebase project, and can be used to identify\na user across every app in your project, regardless of how the user signs in.\n\n- In your apps, you can get the user's basic profile information from the\n [`firebase::auth::User`](/docs/reference/cpp/class/firebase/auth/user) object:\n\n ```c++\n firebase::auth::User user = auth-\u003ecurrent_user();\n if (user.is_valid()) {\n std::string name = user.display_name();\n std::string email = user.email();\n std::string photo_url = user.photo_url();\n // The user's ID, unique to the Firebase project.\n // Do NOT use this value to authenticate with your backend server,\n // if you have one. Use firebase::auth::User::Token() instead.\n std::string uid = user.uid();\n }\n ```\n- In your Firebase Realtime Database and Cloud Storage\n [Security Rules](/docs/database/security/user-security), you can\n get the signed-in user's unique user ID from the `auth` variable,\n and use it to control what data a user can access.\n\nYou can allow users to sign in to your app using multiple authentication\nproviders by [linking auth provider credentials to an\nexisting user account.](/docs/auth/cpp/account-linking)\n\nTo sign out a user, call [`SignOut()`](/docs/reference/cpp/class/firebase/auth/auth#signout): \n\n```c++\nauth-\u003eSignOut();\n```"]]
