I am using the following code to try add another sheet to an existing excel file...
Dim workBookPart As WorkbookPart = spreadsheetdoc.AddWorkbookPart()
This code works fine for inserting the first sheet, but throws "Only one instance of the type is allowed for this parent" when there is already an existing sheet.
Am I misunderstanding something?
Please help.
http://sites.google.com/site/carrollsoftware/products/task-manager