Question

I am trying to call a method I have written in C# from VBScript.

I have followed just about all of the instructions I can find on the web and am still having problems.

Specifically I am getting

Error: ActiveX component can’t create object

Code: 800A01AD

So far I have done the following:

1. Set ComVisible(true)
2. Registered using regasm /codebase
3. Strong named my assembly
4. Confirmed it is in the registry and points to the correct location
5. Made the class public
6. Have no static methods
7. Made the method I want to call public
8. Have a parameterless constructor
9. Explicitly defined a GUID

My VBScript looks like this:

set oObject = CreateObject("TTTTTT.FFFFF.CCCCCCCCC")

My C# code looks like this:

using System;
using System.IO;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace XXXXX.YYYYY
{
    [ComVisible(true)]
    [Guid("3EB62C37-79BC-44f7-AFBD-7B8113D1FD4F")]
    [ProgId("TTTTTT.FFFFF.CCCCCCCCC")]
    public class CCCCCCCCC
    {
        public void MyFunc()
        {
            //
        }
    }
}

Can anyone help?

Answer 1

Here’s a simple project with only a few steps, to get you started.

C# code:

using System;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;

[assembly:System.CLSCompliant(true)]
[assembly: ComVisible(true)]
// The following GUID is for the ID of the typelib if this project is exposed to COM
[assembly: Guid("7d9c5cd3-73d4-4ab1-ba98-32515256c0b0")]

namespace Cheeso.ComTests
{
    [Guid("7d9c5cd3-73d4-4ab1-ba98-32515256c0b1")]
    public class TestReply
    {
        public string salutation;
        public string name;
        public string time;
    }

    [Guid("7d9c5cd3-73d4-4ab1-ba98-32515256c0b2")]
    public class TestObj
    {
        // ctor
        public TestObj () {}

        public TestReply SayHello(string addressee)
        {
            return SayHello(addressee, "hello");
        }

        public TestReply SayHello(string addressee, string greeting)
        {
            string x = String.Format("{0}, {1}!", greeting, addressee);
            Console.WriteLine("{0}", x);

            TestReply r = new TestReply
            {
                salutation = greeting,
                name = addressee,
                time = System.DateTime.Now.ToString("u")
            };
            return r;
        }
    }
}

VBScript client code:

Function Main()
    Dim obj
    Dim reply
    set obj = CreateObject("Cheeso.ComTests.TestObj")
    Set reply = obj.SayHello("Evgeny")
    WScript.Echo "Reply at: " & reply.time
    Set reply = obj.SayHello_2("Evgeny", "wassup")
    WScript.Echo "Reply at: " & reply.time
End Function

Main

To build:

(produce your .snk file, once)
csc.exe /t:library /debug+ /keyfile:Foo.snk /out:TestObj.dll TestObj.cs
regasm /codebase TestObj.exe

Then just run the vbscript (through cscript.exe).

Once you get the basic thing working, you can tweak it, add GAC, make the typelib explicit, add an explicit ProgId, and so on.

ps: FYI, this example shows what happens with overloaded .NET methods on a class registered for interop. There’s an implicit _2 (_3, _4, etc) appended to the method name.