private void dataGridViewProveedor_DoubleClick(object sender, EventArgs e)
        {
            var codigo = Convert.ToInt32(dataGridViewProveedor.CurrentRow.Cells[0].Value);

            Proveedor         = proveedorBL.ObtenerProveedorPorId(codigo);
            this.DialogResult = DialogResult.OK;
            this.Close();
        }