private void bNewPayment_Click(object sender, EventArgs e) { AddPayment addPayment = new AddPayment(selectedContractId); var result = addPayment.ShowDialog(); if (result == DialogResult.OK) { PaymentRepository paymentRepository = new PaymentRepository(); ContractRepository repository = new ContractRepository(); radGridView1.DataSource = repository.getContractsByCustomerId(customerId).ToList(); radGridView2.DataSource = paymentRepository.getPaymentsByContractId(selectedContractId).ToList(); } }