Firebase Facebook推特提供程序getEmail空

firebase.auth().onAuthStateChanged(function(user) {
  if (user) {
    user.providerData.forEach(function(profile) {
      console.log("Provider-specific: ", profile.providerId);
      console.log("Email: ", profile.email);
    });
  }
});

const facebookProvider = new firebase.auth.FacebookAuthProvider();
facebookProvider.addScope('email'); // 请求电子邮件权限
firebase.auth().signInWithPopup(facebookProvider);

// 初始化Firebase
firebase.initializeApp(firebaseConfig);

// 创建Facebook提供程序实例并添加电子邮件权限
const facebookProvider = new firebase.auth.FacebookAuthProvider();
facebookProvider.addScope('email');

// 使用弹出窗口方式登录
firebase.auth().signInWithPopup(facebookProvider).then(function(result) {
  // 用户成功登录
  const user = result.user;
  console.log("User email:", user.email);
}).catch(function(error) {
  // 处理登录错误
  console.error("Error signing in:", error);
});