Question

I am attempting to send a message via sockets from VBA. I have made static .NET classes to do this (for use in other .NET applications).

How do I use them in VBA?

I found VBA syntax for using shell32.dll functions that look like this, but I can not do this as when I build my library geared for COM use I can’t have static routines (and research says COM doesn’t like static fields). How did Shell32 do it?

Private Declare Function SHGetPathFromIDList Lib "shell32.dll" Alias "SHGetPathFromIDListA" (ByVal pidl As Long, ByVal pszPath As String) As Long

I figured out how to do it by having VBA instantiate a class and call the routine from that, but I can only implement this by adding a reference to my .DLL in VBA’s References section (which means the end user has to have it installed in a static place).

TL;DR; How do I use static routines made in C# .NET in VBA by having the library in the same directory as the excel file? (.xlsm, or .xlsb)

Answer 1

You cannot pass class objects between VBA and a DLL, only COM objects. You would need to wrap your class in a COM object, with COM methods and properties rather than class methods and properties.

You can also call DLL methods as you provide in the example – those are just functions, not class functions. You would need to (in C#) create a function that then created the class and called the function.