dotnet thoughts

Few days before I got a requirement to use a .Net assembly in VBScript, but it was not working. But today I got the solution. It was related to my 64bit OS. In this post I am discussing how to create and use a .net assembly in VBScript or Javascript.

First we need to create a class library. Set the ComVisible attribute to true in the AssemblyInfo.cs manually.

[assembly: ComVisible(true)]

Or you can do it using Properties > Application Tab and select Assembly Information, from the Assembly Information dialog, Check the Make assembly COM-Visible check box.

Make Assembly COM Visible option from Assembly Information dialog

Build the assembly. Now we need register the assembly. We can do it using RegAsm.exe. If your OS in 64 bit, then you need to use Regasm command from Framework64 folder(Normally it will be C:\Windows\Microsoft.NET\Framework64\ folder). For running RegAsm command it is recommended to sign the assembly. You can Sign the assembly Properties > Signing Tab.

Sign Assembly option

As RegAsm command add / update information to Windows Registry, you need to run the RegAsm command as Administrator, otherwise it will not work.

You can register the assembly using following command, like this

regasm /codebase assemblyname.dll

You can unregister the assembly using RegAsm command, like this

regasm /u assemblyname.dll

That’s it. Now you can create the object of the .net assembly in VBScript. Like this, it will add 10 and 20 using C# Add method and returns the value.

Dim calcLib
Set calcLib = CreateObject("CalcLib.Math")
Dim result
result = calcLib.Add (10 , 20)
msgbox result

And here is the C# Class, which we are invoked from VBScript.

namespace CalcLib
{
    public class Math
    {
        public int Add(int number1, int number2)
        {
            return number1 + number2;
        }
    }
}

Happy Coding