4.7. Secondary Modules
Our application will have only one secondary module, named “Invoices”. Secondary modules typically contain larger numbers of records than primary ones and new records are added to them frequently.
An invoice consists of a title where some general attributes are described (number, date, customer …) and invoice lines with the list of products, their quantities, prices, etc. It is convenient to have two grids for such documents: the main one showing the invoice header data and the detail one for the list of products sold. We will need one DataGridView component for each entity on the document form, binding the appropriate BindingSource to each.
Figure 26. Invoice form