[RESOLVIDO] Formulário não fecha

Fiz a implementação como mostrado na aula, entretanto o formulário não fechou. Podem me ajudar?

[EDIT] Eu não havia colocado 'Navigator.pop(context);' dentro do 'Confirmar' do AlertDialog, por isso o formulário não fechava.

[imports]

class TransferenciaForm extends StatefulWidget {
  final Contato contato;

  TransferenciaForm(this.contato);

  @override
  _TransferenciaFormState createState() => _TransferenciaFormState();
}

class _TransferenciaFormState extends State<TransferenciaForm> {
  final TextEditingController _valueController = TextEditingController();
  final TransferenciaWebClient _webClient = TransferenciaWebClient();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Nova transferência'),
      ),
      body: SingleChildScrollView(
        child: Padding(
          padding: const EdgeInsets.all(16.0),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: <Widget>[
              Text(
                widget.contato.nome,
                style: TextStyle(
                  fontSize: 24.0,
                ),
              ),
              Padding(
                padding: const EdgeInsets.only(top: 16.0),
                child: Text(
                  widget.contato.conta.toString(),
                  style: TextStyle(
                    fontSize: 32.0,
                    fontWeight: FontWeight.bold,
                  ),
                ),
              ),
              Padding(
                padding: const EdgeInsets.only(top: 16.0),
                child: TextField(
                  controller: _valueController,
                  style: TextStyle(fontSize: 24.0),
                  decoration: InputDecoration(labelText: 'Valor'),
                  keyboardType: TextInputType.numberWithOptions(decimal: true),
                ),
              ),
              Padding(
                padding: const EdgeInsets.only(top: 16.0),
                child: SizedBox(
                  width: double.maxFinite,
                  child: RaisedButton(
                    child: Text('Transferir'),
                    onPressed: () {
                      final double valor =
                          double.tryParse(_valueController.text);
                      final transferenciaCriada =
                          Transferencia(valor, widget.contato);
                      showDialog(
                        context: context,
                        builder: (contextDialog) {
                          return TransferenciaAuthDialog(
                            onConfirm: (String password) {
                              _save(transferenciaCriada, password, context);
                            },
                          );
                        },
                      );
                    },
                  ),
                ),
              )
            ],
          ),
        ),
      ),
    );
  }

  void _save(Transferencia transferenciaCriada, String password,
      BuildContext context) async {
    _webClient
        .save(transferenciaCriada, password)
        .then((transferenciaRecebida) {
      if (transferenciaRecebida != null) {
        Navigator.pop(context);
      }
    });
  }
}

import 'package:flutter/material.dart';

class TransferenciaAuthDialog extends StatefulWidget {
  final Function(String) onConfirm;

  TransferenciaAuthDialog({
    @required this.onConfirm,
  });

  @override
  _TransferenciaAuthDialogState createState() =>
      _TransferenciaAuthDialogState();
}

class _TransferenciaAuthDialogState extends State<TransferenciaAuthDialog> {
  final TextEditingController _passwordController = TextEditingController();

  @override
  Widget build(BuildContext context) {
    return AlertDialog(
      title: Text("Autenticação"),
      content: TextField(
        controller: _passwordController,
        obscureText: true,
        textAlign: TextAlign.center,
        style: TextStyle(
          fontSize: 64,
          letterSpacing: 24,
        ),
        decoration: InputDecoration(
          border: OutlineInputBorder(),
        ),
        maxLength: 4,
        keyboardType: TextInputType.number,
      ),
      actions: [
        FlatButton(
          onPressed: () {
            Navigator.pop(context);
          },
          child: Text("CANCEL"),
        ),
        FlatButton(
          onPressed: () {
            widget.onConfirm(_passwordController.text);
#
#  O erro foi não ter colocado o .pop abaixo 
#           Navigator.pop(context);
#
          },
          child: Text("CONFIRM"),
        ),
      ],
    );
  }
}