public void Login() { LoginViewModel vm = new LoginViewModel(); if (vm.Autenticar(new Models.Usuario() { Login = LoginField.Text, Senha = SenhaField.Text })) { Preferences.Set("isLogged", true); MessagingCenter.Send <object>(this, App.EVENT_LAUNCH_MAIN_PAGE); } else { DisplayAlert("Erro ao logar", "Por favor, confira o usuario e senha", "Ok"); } }