Making an MS Excel User-Defined-Functions

Question

i'm trying to create a User Defined Function for MS Excel in C#.

But no matter what I try, when I try to add the Add-in to Excel I always get the infamous "The file you have selected does not contain a new automation server, or you do not have sufficient privileges to register the automation server" error.

Here's the code that I took from and online example just to try it out:

// C#

using System;
using System.Runtime.InteropServices;
using Microsoft.Win32;

namespace AutomationAddin
{
    [ClassInterface(ClassInterfaceType.AutoDual)]
    public class MyUdf
    {
        public MyUdf()
        {
        }

        public double addMeTest(double x, double y)
        {
            return x + y;
        }

        [ComRegisterFunctionAttribute]
        public static void RegisterFunction(Type t)
        {
            Microsoft.Win32.Registry.ClassesRoot.CreateSubKey(
                "CLSID\\{" + t.GUID.ToString().ToUpper() +
                   "}\\Programmable");
        }

        [ComUnregisterFunctionAttribute]
        public static void UnregisterFunction(Type t)
        {
            Microsoft.Win32.Registry.ClassesRoot.DeleteSubKey(
                "CLSID\\{" + t.GUID.ToString().ToUpper() +
                  "}\\Programmable");
        }
    }
}

I tried this with MS Visual Studio 2012 on Excel 2013 x64 and Excel 2010 x86

SolutionsI've found and tried with no success:

[ClassInterface(ClassInterfaceType.AutoDual)] as seen in the code
[ComRegisterFunctionAttribute] AND [ComUnregisterFunctionAttribute] as seen in the code
regasm /codebase did nothing as well
Turning on/off "Register COM interop" (VS running as admin when building)
[assembly: ComVisible(true)] set to true
Tried different code examples from the web
Read this on stackoverflow: How to get COM Server for Excel written in VB.NET installed and registered in Automation Servers list?
I've also tried all of the above together - no luck here
Ran Excel in admin mode

So please guys, if you can tell me what am I missing here and maybe even tell me what should I do to make it work I would be so grateful! Thanks in advance!

I will gladly provide any additional info if needed.

P.S. Haven't had any sleep for two nights now so I might be screwing something up in a really stupid way. If someone could test this code if it works and tell me their project setup it just might help.

http://www.codeproject.com/Articles/7753/Create-an-Automation-Add-In-for-Excel-using-NET seems to address your problem, hope it helps! — JuStDaN, Dec 20 '13 at 02:57
@JuStDaN Thanks, but the code example in my question is exactly for that very page and I've tried their solutions. — Janis Vepris, Dec 20 '13 at 03:01
@Janisimo, do you compile your assembly for AnyCPU platform? — user626528, Dec 20 '13 at 03:30
@Janisimo, I believe you should, but trying different options might help. Also, don't forget to use the version of regasm (32 or 64 bit) matching your Excel bitness. — user626528, Dec 20 '13 at 09:08

score 2 · Answer 1 · answered Dec 20 '13 at 03:04

2

You can try this library https://exceldna.codeplex.com, it simplifies creation of UDFs a lot.

answered Dec 20 '13 at 03:04

user626528

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Thank you very much for your suggestion. I've successfully created XLL UDF's before with this tool, it's great. But the problem is that I have a university assignment and they want me to create a COM automation Add-in, that's a requirement :( – Janis Vepris Dec 20 '13 at 03:07

Making an MS Excel User-Defined-Functions

1 Answers1