private void BtnSave_Click(object sender, RoutedEventArgs e) { string code = txtCode.Text; string description = txtDescription.Text; Group group = (Group)cmbGroups.SelectedItem; VAT vat = (VAT)cmbVATs.SelectedItem; decimal.TryParse(txtNetPrice.Text, out decimal netprice); Product product; if (isNew) { product = new Product(code, description, netprice, vat, group); globalService.AddProduct(product); } else { product = (Product)lstProducts.SelectedItem; product.Code = code; product.Description = description; product.NetPrice = netprice; product.Vat = vat; product.ProductGroup = group; } PopulateListbox(); DefaultSituation(); lstProducts.SelectedItem = product; LstProducts_SelectionChanged(null, null); }