在无Firebase的Flutter应用程序中添加Facebook和Google身份验证

dependencies:
  flutter_facebook_auth: ^3.5.0
  google_sign_in: ^5.0.0

import 'package:flutter_facebook_auth/flutter_facebook_auth.dart';

// ...

Future<void> loginWithFacebook() async {
  final LoginResult result = await FacebookAuth.instance.login();

  if (result.status == LoginStatus.success) {
    final AccessToken accessToken = result.accessToken;
    // 在这里可以获取用户的访问令牌并执行其他操作
  } else {
    // 登录失败的处理
  }
}

import 'package:google_sign_in/google_sign_in.dart';

// ...

Future<void> loginWithGoogle() async {
  final GoogleSignIn googleSignIn = GoogleSignIn();

  try {
    final GoogleSignInAccount account = await googleSignIn.signIn();
    final GoogleSignInAuthentication authentication =
        await account.authentication;

    // 在这里可以获取用户的身份验证信息并执行其他操作
  } catch (error) {
    // 登录失败的处理
  }
}