Aktivieren Sie auf dem Tab Anmeldemethode die Anmeldemethode Google und klicken Sie auf Speichern.
Laden Sie die aktualisierte Firebase-Konfigurationsdatei herunter, wenn Sie in der Console dazu aufgefordert werden.
(google-services.json), die jetzt die Informationen zum OAuth-Client enthält
für Google Log-in erforderlich.
Verschieben Sie diese aktualisierte Konfigurationsdatei in Ihr Android Studio-Projekt und ersetzen Sie sie dabei.
die inzwischen veraltete Konfigurationsdatei.
Weitere Informationen finden Sie unter Firebase zu meinem Android-Projekt hinzufügen.
Auf die Klasse firebase::auth::Auth zugreifen
Die Klasse Auth ist das Gateway für alle API-Aufrufe.
Fügen Sie die Auth- und App-Headerdateien hinzu:
#include"firebase/app.h"#include"firebase/auth.h"
Erstellen Sie in Ihrem Initialisierungscode einen
Klasse firebase::App.
Folgen Sie der Anleitung für Android und iOS +, um ein ID-Token für die Google-Anmeldung abzurufen.
Nachdem sich ein Nutzer erfolgreich angemeldet hat, tauschen Sie das ID-Token gegen Firebase-Anmeldedaten aus und authentifizieren Sie sich mit Firebase:
Wenn Ihr Programm eine Update-Schleife hat, die regelmäßig ausgeführt wird (z. B. 30- oder 60-mal pro Sekunde), können Sie die Ergebnisse einmal pro Update mit Auth::SignInAndRetrieveDataWithCredentialLastResult prüfen:
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());}}
Einige Programme haben Update-Funktionen, die 30 oder 60 Mal pro Sekunde aufgerufen werden.
So folgen beispielsweise viele Spiele diesem Modell. Diese Programme können die LastResult-Funktionen aufrufen, um asynchrone Aufrufe abzufragen.
Wenn Ihr Programm jedoch ereignisgesteuert ist, möchten Sie möglicherweise Callback-Funktionen registrieren.
Nach Abschluss der Future wird eine Callback-Funktion aufgerufen.
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);}
Die Rückruffunktion kann auch eine Lambda-Funktion sein.
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);}
Nächste Schritte
Nachdem sich ein Nutzer zum ersten Mal angemeldet hat, wird ein neues Nutzerkonto erstellt und
die mit den Anmeldedaten verknüpft sind, d. h. Nutzername und Passwort,
oder Authentifizierungsanbieter-Informationen – also für den Nutzer, mit dem sich der Nutzer angemeldet hat. Diese neue
-Konto wird als Teil Ihres Firebase-Projekts gespeichert und kann verwendet werden, um
in jeder App in Ihrem Projekt einen Nutzer erreichen,
unabhängig davon, wie er sich anmeldet.
In Ihren Apps können Sie die grundlegenden Profilinformationen des Nutzers über das Objekt firebase::auth::User abrufen:
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();}
In Firebase Realtime Database und Cloud StorageSicherheitsregeln können Sie
die eindeutige Nutzer-ID des angemeldeten Nutzers aus der Variablen auth abrufen,
und steuern, auf welche Daten ein Nutzer zugreifen kann.
[[["Leicht verständlich","easyToUnderstand","thumb-up"],["Mein Problem wurde gelöst","solvedMyProblem","thumb-up"],["Sonstiges","otherUp","thumb-up"]],[["Benötigte Informationen nicht gefunden","missingTheInformationINeed","thumb-down"],["Zu umständlich/zu viele Schritte","tooComplicatedTooManySteps","thumb-down"],["Nicht mehr aktuell","outOfDate","thumb-down"],["Problem mit der Übersetzung","translationIssue","thumb-down"],["Problem mit Beispielen/Code","samplesCodeIssue","thumb-down"],["Sonstiges","otherDown","thumb-down"]],["Zuletzt aktualisiert: 2025-09-04 (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```"]]
