private void btnCalculate_Click(object sender, EventArgs e) { Logic.Logic logic = new Logic.Logic(); CalculateVatRequest request = CreateCalculateVatRequest(); CalculateVatResponse response = logic.HandleCalculateRequest(request) as CalculateVatResponse; if (response != null && response.IsValid) { //zakładając że chcemy zaokrąglenie response.Result = Math.Round(response.Result, 2, MidpointRounding.AwayFromZero); tbBrutto.Text = String.Format("{0:0.##}", response.Result); } else { // można też gdzieś wrzucić komunikaty walidacyjne tbBrutto.Text = String.Empty; } }