Excel 2010 64 bit can't create .net object
-
02-10-2019 - |
Question
I have a simple class library that I use in Excel. Here is a simplification of my class...
using System;
using System.Runtime.InteropServices;
namespace SimpleLibrary
{
[ComVisible(true)]
public interface ISixGenerator
{
int Six();
}
public class SixGenerator : ISixGenerator
{
public int Six()
{
return 6;
}
}
}
In Excel 2007 I would create a macro enabled workbook and add a module with the following code:
Public Function GetSix()
Dim lib As SimpleLibrary.SixGenerator
lib = New SimpleLibrary.SixGenerator
Six = lib.Six
End Function
Then in Excel I could call the function GetSix() and it would return six. This no longer works in Excel 2010 64bit. I get a Run-time error '429': ActiveX component can't create object.
I tried changing the platform target to x64 instead of Any CPU but then my code wouldn't compile unless I unchecked the Register for COM interop option, doing so makes it so my macro enable workbook cannot see SimpleLibrary.dll as it is no longer regsitered.
Any ideas how I can use my library with Excel 2010 64 bit?
Solution
You haven't described in detail how your created your .NET assembly. However, there are a certain number of steps required to expose the assembly to COM:
Add the following attributes to your code:
using System; using System.Runtime.InteropServices; namespace SimpleLibrary { [ComVisible(true)] [Guid("71F645D0-AA78-4447-BA26-3A2443FDA691")] public interface ISixGenerator { int Six(); } [ComVisible(true)] [ProgId("SimpleLibrary.SixGenerator")] [Guid("8D59E0F6-4AE3-4A6C-A4D9-DFE06EC5A514")] [ClassInterface(ClassInterfaceType.AutoDispatch)] public class SixGenerator : ISixGenerator { [DispId(1)] public int Six() { return 6; } } }
Your assembly must be signed (Project -> Properties... -> Signing, create a strong key file and check the box to sign the assembly
The following command is necessary to register the assembly (all in one line):
C:\Windows\Microsoft.NET\Framework64\v2.0.50727\RegAsm.exe SimpleLibrary.dll /tlb SimpleLibrary.tlb /codebase
This creates a .tlb type library file which you will have to reference from your VBA project (Tools -> References -> Browse... in your VBA editor)
Adjust the VBA code:
Public Function GetSix() Dim lib As SimpleLibrary.SixGenerator Set lib = New SimpleLibrary.SixGenerator GetSix = lib.Six End Function
You will find the steps described in more detail in this article on Microsoft's support database:
How to call a Visual Basic .NET or Visual Basic 2005 assembly from Visual Basic 6.0