Question

I have ASP.NET web service, which is creating file in XML table format.

I need to convert this file into Excel 2003 format.

What can I use instead of Microsoft.Interop library?

UPDATE: I also need to copy format from the original file.

Answer 1

I’ve found the answer by myself.

I could not use different libraries, because I had to open file in XML Table format and resave it to Excel 2003 format.

Maybe my experience in this question will help someone. I used Windows Server 2008 with IIS 7.0 and Excel Library Microsoft.Office.Interop.Excel version 12.

Microsoft says, that using Interop DLL may cause unpredictable result, but it’s NOT impossible.

The main problem of using Interop classes lies into access to launch DCOM applications by user, that starts web-service.

To make web-service works correct in my way I did next:

1. I opened “dcomcnfg” and disable authorization for all DCOM
   components.

   Another way is to find exactly your DCOM objects and give
   permissions to local launch to the user, that starts the service.

2. Gave permissions to registry branch

   HKEY_CLASSES_ROOT\CLSID\ID_OF_MICROSOFT_APPLICATION_CLASS

   ID_OF_MICROSOFT_APPLICATION_CLASS = class, which contained in
   web-server error while accessing to Interop DLL

3. It’s very strange, but important: I created folder

   for 86x: C:\Windows\System32\config\systemprofile\Desktop
   for 64x: C:\Windows\SysWOW64\config\systemprofile\Desktop

4. Gave write permission to web-service user to all folders, which my
   web-service use, including folder from item (3).

If your web-service works under NETWORK SERVICE try to change it to some local user, maybe it may help you.