jpoi5

Especially noticeable when reading from a not-very-small workbook, even if it just contains multiple sheets with some tens of thousands of rows. Slow method that opens the workbook multiple times (and, I guess, reads it/interprets its XML completely each time to load it into memory): Dim...

Dim i As Int Dim theSheet As PoiSheet = ... Dim joTheSheet As JavaObject = theSheet Dim theSheetWriter As XLSheetWriter = ... Dim theSheetLastRow1 As Int = theSheet.LastRowNumber + 1 ' One-based index of the last row in the sheet Dim theSheetLastCol0 As Int = theSheet.GetRow(0).Cells.Size - 1 '...