Reading Excel files from C#

Question

Is there a free or open source library to read Excel files (.xls) directly from a C# program?

It does not need to be too fancy, just to select a worksheet and read the data as strings. So far, I've been using Export to Unicode text function of Excel, and parsing the resulting (tab-delimited) file, but I'd like to eliminate the manual step.

Answer 1

Late to the party, but I'm a fan of LinqToExcel

Answer 2

Lately, partly to get better at LINQ.... I've been using Excel's automation API to save the file as XML Spreadsheet and then get process that file using LINQ to XML.

Answer 3

Koogra is an open-source component written in C# that reads and writes Excel files.

Answer 4

Not free, but with the latest Office there's a very nice automation .Net API. (there has been an API for a long while but was nasty COM) You can do everything you want / need in code all while the Office app remains a hidden background process.

Answer 5

The solution that we used, needed to:

• Allow Reading/Writing of Excel produced files
• Be Fast in performance (not like using COMs)
• Be MS Office Independent (needed to be usable without clients having MS Office installed)
• Be Free or Open Source (but actively developed)

There are several choices, but we found NPoi (.NET port of Java's long existing Poi open source project) to be the best: http://npoi.codeplex.com/

It also allows working with .doc and .ppt file formats

Answer 6

I did a lot of reading from Excel files in C# a while ago, and we used two approaches:

• The COM API, where you access Excel's objects directly and manipulate them through methods and properties
• The ODBC driver that allows to use Excel like a database.

The latter approach was much faster: reading a big table with 20 columns and 200 lines would take 30 seconds via COM, and half a second via ODBC. So I would recommend the database approach if all you need is the data.

Cheers,

Carl