This example illustrates how to customize the Insert Merge Field menu to group merge field names with identical prefixes (Employees and Customers in this example) into submenus.
The DataBindingController class generates menu items/subitems from the mail merge data source on the fly. These items are added to a popup menu.
When a custom menu item is clicked, the CustomInsertMergeFieldMenuItem.OnClick method is executed to insert the current merge field.
When you click the Insert Merge Field Ribbon item, the built-in Insert Merge Field form is shown.
Note that the custom Insert Merge Field Ribbon item uses resources (images) from the project's Images folder to initialize the BarButtomItem.LargeGlyph and BarButtonItem.Glyph properties. Customize the LargeGlyph and Glyph properties of the CustomInsertMergeFieldItem class to use another source for images.