Using a C# dll inside EXCEL VBA

Question

I am running into a little problem here and need you guys\' help.

I have a C# DLL exposed through COM interop. It is working alright, but apparently the deployment o

Answer 1

These are the using statements to put at the top of your class which are key:

using System.Diagnostics; using RGiesecke.DllExport;

Also ensure that you have a project started before the Nuget PM statement to install the template above. I am new at this - I am sure there are others as well. I am using AutoCAD VBA and got another error since it is 64 bit - I had to use PtrSafe (etc) in the Declare statement for VBA to continue without errors (see MS docs for this http://support.microsoft.com/kb/983043)

It worked btw!

My final code (based on the above)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;
using System.Diagnostics;
using RGiesecke.DllExport;

namespace ClassLibrary3
{
    [ComVisible(true), ClassInterface(ClassInterfaceType.AutoDual)]
    public class Class1
    {
        public string Text
        {
            [return: MarshalAs(UnmanagedType.BStr)]
            get;
            [param: MarshalAs(UnmanagedType.BStr)]
            set;
        }

        [return: MarshalAs(UnmanagedType.BStr)]
        public string TestMethod()
        {
            return Text + "...";
        }
    }

    static class UnmanagedExports
    {
        [DllExport]
        [return: MarshalAs(UnmanagedType.IDispatch)]
        static Object CreateDotNetObject(String text)
        {
            return new Class1 { Text = text };
        }
    }
}

and my vba code:

#If VBA7 Then
    Private Declare PtrSafe Function CreateDotNetObject Lib "G:\gitRepository\VS\ClassLibrary3\ClassLibrary3\bin\Debug\ClassLibrary3.dll" (ByVal text As String) As Object
#Else
    Private Declare Function CreateDotNetObject Lib "G:\gitRepository\VS\ClassLibrary3\ClassLibrary3\bin\Debug\ClassLibrary3.dll" (ByVal text As String) As Object
#End If

Sub test()

  Dim instance As Object

  Set instance = CreateDotNetObject("Test 1")
  Debug.Print instance.text

  Debug.Print instance.TestMethod

  instance.text = "abc 123" ' case insensitivity in VBA works as expected'

  Debug.Print instance.text
End Sub