private void btn_AddTempProduct_Click(object sender, RoutedEventArgs e) { if (decimal.TryParse(textbox_Price.Text, out price) && price > 0 && textbox_Description != null) { string description = textbox_Description.Text; price = decimal.Parse(textbox_Price.Text); int amount = int.Parse(textBox_ProductAmount.Text); TempProduct NewTemp = _storageController.CreateTempTempProduct(description, price, _tempID); _storageController.TempTempProductList.Add(NewTemp); _posController.AddSaleTransaction(NewTemp, amount); UpdateReceiptEventHandler?.Invoke(this, null); this.Close(); } else { textbox_Description.BorderBrush = Brushes.Red; textbox_Price.BorderBrush = Brushes.Red; } }