如何使用Firebase身份验证检索用于登录链接帐户的登录方法

Question

If i have two linked accounts for the same UserID, lets say, Facebook and email based. When authenticating FireBase triggers the following:

 // Track ID token changes.
    private void IdTokenChanged(object sender, System.EventArgs eventArgs)
    {
        Firebase.Auth.FirebaseAuth senderAuth = sender as Firebase.Auth.FirebaseAuth;
        if (senderAuth == auth && senderAuth.CurrentUser != null)// && !fetchingToken)
        {
            senderAuth.CurrentUser.TokenAsync(false).ContinueWith(
              task =>
              {
                  fetchingToken = true; 
                  UserLoginDetails.provideId = new List<Firebase.Auth.IUserInfo>(senderAuth.CurrentUser.ProviderData)[0].ProviderId;
                  UserLoginDetails.userId = senderAuth.CurrentUser.UserId;
                  UserLoginDetails.name = senderAuth.CurrentUser.DisplayName;
                 //DO MORE STUFF HERE
              }
        }
    }

As you can see i can get user information, and get the Providers using ProviderData .

Issue is that when getting main ProviderId from senderAuth.CurrentUser.ProviderId: you get "Firebase" And from ProviderData you cannot know which is the used to authenticate.

This sounds to me pretty basic to have some info with whom you last logged in with in some field in the main object.

Answer 1

I don't think there's any way to find what profile the user last used to sign in from their profile.

If you need this information, you'll need to capture it when the user signs in. For example from the documentation on signing in with email/password :

auth.SignInWithEmailAndPasswordAsync(email, password).ContinueWith(task => {
  if (task.IsCanceled) {
    Debug.LogError("SignInWithEmailAndPasswordAsync was canceled.");
    return;
  }
  if (task.IsFaulted) {
    Debug.LogError("SignInWithEmailAndPasswordAsync encountered an error: " + task.Exception);
    return;
  }

  Firebase.Auth.FirebaseUser newUser = task.Result;
  Debug.LogFormat("User signed in successfully: {0} ({1})",
      newUser.DisplayName, newUser.UserId);

  this.SignInMethod = "Password";
});

Or if you sign in directly with Credential :

auth.SignInWithCredentialAsync(credential).ContinueWith(task => {
  ...
  this.SignInMethod = credential.Provider;
})