If I google “Aspose cells number format”, I get taken to this address.
There I find the code:
workbook.Save(“NumberFormatting.xls”, FileFormatType.Excel97To2003, SaveType.OpenInExcel, System.Web.HttpContext.Current.Response)
On my system SaveType is not declared.
I am importing Aspose.Cell and System, as per your example.
Also, obviously, there is no “SaveType” parameter in the workbook.Save command.
I am using a recent version of Cells (one or two months old).
What am I doing wrong?