What if any links exist to free Excel "helper" class libraries for C#?

Question

I'm looking for any available free Excel "helper" classes that are written for .net (doesn't have to be C#). I'd like to evaluate what others consider to be useful and generic static (and non static) helper methods. Can be targeted at VSTO or regular Office automation, although that probably doesn't matter.

I guess I should also point out that this question is NOT asking for "what are good alternatives (or free alternatives) to using Excel object model automation. I don't really want links to SS gear, etc, although they are all great products that's not the purpose of the question.

In case I wasn't clear enough in the previous paragraph: I don't want answers that state - use this free (or not free) 3rd party component, instead of Excel object model code.

So basically what i was asking for was user developed C# code libraries that contain VSTO, Office or Excel helper functions such as static methods for working with menus, ribbons, ranges, workbooks, documents, xml (such as the ones otaku mentioned)...

Answer 1

In terms of Office automation for Excel, there are some good PowerShell Open XML cmdlets that can be used for PS or ported to C# at Announcing the Release of PowerTools for Open XML V1.1. Eric White's blog, where this link is, has recently done an more in depth look at Excel automation using Open XML, like Table Markup in Open XML SpreadsheetML. Note about Open XML - although it is the preferred method by many, you don't actually have to use the Open XML SDK - you can just use System.IO.Packaging to gain access to Excel 2007/2010 files.

Also, often overlooked, but the Excel snippets available for VSTO, Open XML and Interop development are great. 1, 2, 3

Also, check out the Excel samples for VB @ http://msdn.microsoft.com/en-us/library/8x19fbw1(v=VS.90).aspx. These come installed with VS when you also choose VB as a language during the install.

Update: Just discovered the All-In-One Code Framework (Office) which has a lot of great Excel helper classes. You can find it on: http://1code.codeplex.com/releases/view/51868.

Answer 2

ExcelDNA is a very cool project. It provides a lightweight way to consume .NET code from Excel, with a deployment model which is much easier than VSTO. I found it an interesting alternative to VSTO if you want to write UDF in .NET for instance.