Issues with VB and Aspose

Question

I have the following lines of code:

Dim ms As New MemoryStream(my_memory_stream)
workbook As New Workbook(ms)
workbook.Save("C:\book1.xlsx")

My purpose is to save the stream contained in my_memory_stream into an xlsx file named "book1": the problem is that when I run this code an exception occurr (Invalid Excel2007Xlsx file format). Does anyone know what I'm doing wrong?

Thanks so much!

try to not saving in system root C: .. – matzone Jun 13 '13 at 08:55 — matzone, Jun 13 '13 at 08:55
I tried, but I still have the same problem – Daniele Milani Jun 13 '13 at 08:58 — Daniele Milani, Jun 13 '13 at 08:58
what's in **my_memory_stream** ? – matzone Jun 13 '13 at 09:06 — matzone, Jun 13 '13 at 09:06
The content of an xlsx file (base64 format) – Daniele Milani Jun 13 '13 at 09:11 — Daniele Milani, Jun 13 '13 at 09:11

score 2 · Accepted Answer · answered Jun 13 '13 at 19:42

Most probably, the problem is the base64 format. It is in the form of ASCII characters. You need to convert the Base64 data to binary. And then load the binary data in Workbook class.

' Decode base64
Dim binaryBytes As Byte() = Convert.FromBase64CharArray(base64Data, 0, base64Data.Length)

' Load in MemoryStream
Dim binaryStream As New MemoryStream(binaryBytes)

' Pass memory stream to Workbook
Dim workbook As New Aspose.Cells.Workbook(my_memory_stream)
workbook.Save(dataDir + "workbook-out.xlsx")

Also note that, if your decoding is correct, you can directly save the binary byte or stream to disk and verify that the Excel is saved correctly.

PS. I am a Developer Evangelist at Aspose.

score 0 · Answer 2 · answered Jun 13 '13 at 09:00

It seems that you are trying to save a stream directly to a Excel file. Excel files have a fixed format, and the stream will not be adhering to the standard file protocol of excel.

I think you would like to use Workbook object of Microsoft.office.Interop.Excel namespace.

Issues with VB and Aspose

2 Answers2