Trying to access .NET code from Xojo

General
1

Hi everyone,
i was testing a really old example from the blog for accessing .NET code from Xojo, written in 2014 by Paul Lefebvre.
https://blog.xojo.com/2014/01/03/accessing-net-code-from-xojo

I can add the .Net Library as an ActiveX component, but i always get an error:

There is no class with this name
Dim o As New xojoTestProject.InterfaceImplementation

Isn’t this example up to date anymore? Has anything changed?

2

Not all .NET libraries register them self’s as ActiveX. They need to have ActiveX flag in then project manifest when their compiled if I remember correctly.

3

Thanks Björn,
i think the ActiveX component itself is ok. The error refers only to InterfaceImplementation as if this class is not found, but i can find it in the .net code.

4

Check if the class has the following flag:

<System.Runtime.InteropServices.ComVisible(True)>

The interface you might see in ActiveX / COM but implementation not found if the class is not exposed to ActiveX / COM.

5

I made it exactly like in Paul’s example:

using System.Runtime.InteropServices;

and also

checked the “Register for Com interop” checkbox

in the build section

6

Thanks Björn, now i got it. I didn’t understand that i had to change the InteropServices Flag in the assemblyinfo.cs. Problem solved!

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