Import and Export Excel - What is the best library? [closed]

I'm going to throw my hand in for flat csv files, if only because you've got the greatest control over the code. Just make sure that you read in the rows and process them one at a time (reading the document to the end and splitting will eat up all of your memory - same with writing, stream it out).

Yes, the user will have to save-as CSV in excel before you can process it, but perhaps this limitation can be overcome by training and providing clear instructions on the page?

Finally, when you export to the customer, if you set the mime type to text/csv, Excel is usually mapped to that type so it appears to the user to be 'an Excel file'.

I discovered the Open XML SDK since my original answer. It provides strongly typed classes for spreadsheet objects, among other things, and seems to be fairly easy to work with. I am going to use it for reports in one of my projects. Alas, version 2.0 is not supposed to get released until late 2009 or 2010.

the last version of ExcelPackage that is free under LGPL for commercial projects is, https://www.nuget.org/packages/EPPlus/4.5.3.3

If you need latest and greatest, Commercial license is available here: https://epplussoftware.com/en/LicenseOverview/

I'm still fighting with the export to excel function since my application should export some data to excel-template 2007

this project seems fine to me, and the developer is very responsive to bugs and issues.