exampleScreen.dart

import 'package:flutter/material.dart';

class Profile extends StatefulWidget {
  String nombreProfile = '';
  String apellidoProfile = '';
  @override
  _ProfileState createState() =>
      _ProfileState(apellidoUser: apellidoProfile, nombreUser: nombreProfile);
}

class _ProfileState extends State<Profile> {
  var nombreUser = "";
  var apellidoUser = "";

  _ProfileState({this.apellidoUser, this.nombreUser});

  @override
  Widget build(BuildContext context) {
    //nombre y apellido lo cargo en un textField
    return null;
  }
}

class DrawerWidget extends StatefulWidget {
  @override
  _DrawerWidgetState createState() => _DrawerWidgetState();
}

class _DrawerWidgetState extends State<DrawerWidget> {
  String emailShow = "";

  String nombrePerfil = Profile().nombreProfile;
  String apellidoPerfil = Profile().apellidoProfile;

  getNombreCompleto() {
    String nombreCompleto = '';
    if (nombrePerfil.isEmpty) {
      nombreCompleto = apellidoPerfil;
    } else if (apellidoPerfil.isEmpty) {
      nombreCompleto = nombrePerfil;
    } else
      nombreCompleto = nombrePerfil + ' ' + apellidoPerfil;
    return nombreCompleto;
  }

  cargarEmailShow() async {
    var a = CounterStorage();
    String res = await a.readDynamic('email');

    setState(() {
      emailShow = res;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Drawer(
      child: Container(
        child: ListView(
          children: <Widget>[
            Padding(
              padding: EdgeInsets.all(0),
              child: ListTile(
                  title: Text(
                    getNombreCompleto() ? null : '$emailShow',
                  ),
                  onTap: () {}),
            ),
          ],
        ),
      ),
    );
  }
}