DevExpress GridView ExportToXls/Xlsx not working-CodePudding

I´m currently trying to export my GridView1 to an XLS- and XLSX-File. My Problem is, that the export is not working. I just get an empty file and the following error:

And I can´t find anything regarding this error..

My code is pretty basic:

           Case "barXLS"
                fileName = $"C:\Temp\{dt.Year}{dt.Month}{dt.Day}{dt.Second}_Export.xls"
                GridView1.ExportToXls(fileName)
            Case "barXLSX"
                fileName = $"C:\Temp\{dt.Year}{dt.Month}{dt.Day}{dt.Second}_Export.xlsx"
                GridView1.ExportToXlsx(fileName)

But I tried a lot of settings for the GridView and for XlsExportOptionsEx but none of them worked. When I try to open the XLS-Sheet I get an error saying that the file is corrupted.

I would really appreciate your help, thank you!

CodePudding user response：

I added the following line to my column-defintions:

columns(i).UnboundDataType = GetType(<DATATYPE>)

After that the export worked as expected.