I have implemented the ListDataValidationRule code to add a dropdownlist to the spreadsheet. Based on the code I can find and the searching I have conducted, it seems to be correct, however the dropdown does not appear in the control.
The dropdown list does appear in Excel when I export the file.
Dim Context As ListDataValidationRuleContext = New ListDataValidationRuleContext(CurrentWorksheet, CurrentCellIndex)
Add support for creating Tables and applying tables styles (predefined ones or custom).
If a worksheet spans more than one page, you can print row and column headings or labels (also called print titles) on every page to ensure that the data is properly labeled.