//Search for Copies of the Item by relevant parameters //Excluding the ISBN, which is unique for each Item private void btnQuantity_Click(object sender, RoutedEventArgs e) { //Get the Item to search for from the DataGrid AbstractItem item = (AbstractItem)dataLib.SelectedItem; //Show the result of the Message Box GuiMsgs.Info($"The quantity of this {item.ItemType} is {mainLibrary.ItemQuantity(item)}"); }