Flutter/Firebase/Firestore - 注册不会将数据推送到数据库

Question

I am trying to record some additional user data when they sign up to my app. My signup process looks like this:

    String ref = "users";
    Future<bool> signUp(
    String email,
    String password,
    String firstName,
    String lastName,
  ) async {
    try {
      _status = Status.Authenticating;
      notifyListeners();
      await    _auth
          .createUserWithEmailAndPassword(email: email, password: password);
      FirebaseFirestore.instance.collection(ref).doc(user.uid).set({
        'id': user.uid,
        'displayName': firstName.trim() + " " + lastName.trim(),
        'email': email.trim(),
        'createdat': DateTime.now()
      });
      return true;
    } catch (e) {
      _status = Status.Unauthenticated;
      notifyListeners();
    } return false;
  }

I can't work out why, when the user enters their data and signs up, the specified values aren't pushed to firestore. Can someone help me out? Thanks. Here is where I have implemented my code:

           child: RaisedButton(
                      child: Text('Create an Account', style: TextStyle(color: Colors.white),),
                      onPressed: ()  async {
                        if (validate()) {
                          _formKey.currentState.reset();
                          user.signUp(_emailController.text, _passwordController.text, _firstNameController.text, _lastNameController.text);
                          Navigator.pushReplacement(
                              context, MaterialPageRoute(builder: (context) => Home()));
                        }
                      }),

Answer 1

So, as mentioned in the comments, it should be like this:

  await FirebaseFirestore.instance.collection(ref).doc(user.uid).set({
    'id': user.uid,
    'displayName': firstName.trim() + " " + lastName.trim(),
    'email': email.trim(),
    'createdat': DateTime.now()
  });