private void AtualizaHistorico()
        {
            ttbCodigo.Clear();
            btnRegistrar.Text = "Registrar";
            rbtTrans.Enabled = true;

            if (cbbDestino.SelectedIndex != -1)
            {
                ggbHistorico.Enabled = true;

                MovContas mov = new MovContas(new BancoM());
                if (rbtUltimosLan.Checked)
                {
                    dgvHistorico.DataSource = mov.UltimosLancamentos(int.Parse(cbbDestino.SelectedValue.ToString()));
                }
                else if (rbtPeriodo.Checked)
                {
                    dgvHistorico.DataSource = mov.porPeriodo(int.Parse(cbbDestino.SelectedValue.ToString()), dtpIni.Value.AddDays(-1), dtpFim.Value);
                }
                else
                {
                    char mov_tipo = 'X';
                    if(cbbTipo.SelectedIndex != -1)
                        char.TryParse(cbbTipo.SelectedValue.ToString(),out mov_tipo);
                    dgvHistorico.DataSource = mov.porTipo(int.Parse(cbbDestino.SelectedValue.ToString()),mov_tipo);
                }
            }
            else
            {
                ggbHistorico.Enabled = false;
                MovContas mov = new MovContas(new BancoM());
                dgvHistorico.DataSource = mov.UltimosLancamentos(0);
            }
        }
        private void btnLocalizar_Click(object sender, EventArgs e)
        {
            MovContas mov = new MovContas(new BancoM());

            if (rbtExibirTodos.Checked)
            {
                dgvHistorico.DataSource = mov.exibirTodos();
            }
            else if (rbtCredito.Checked)
            {
                dgvHistorico.DataSource = mov.porTipo('C');
            }
            else if (rbtDebito.Checked)
            {
                dgvHistorico.DataSource = mov.porTipo('D');
            }
            else if (rbtPeriodo.Checked)
            {
                dgvHistorico.DataSource = mov.porPeriodo(dtpIni.Value.AddDays(-1), dtpFim.Value);
            }
        }