COM Interop (how to pass an array to the com) via classic ASP

Question

I need to create a com object for my classic asp, since i can create a .net Assembly and have it 'Interop' with com, so i proceeded to create a .net Assembly like this:-

using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Linq;
using System.Text;
using System.Data.SqlClient;
using System.Data;
using System.Configuration;
using System.Web;


namespace LMS
{

[ComVisible(true)]
public class Calc
{

    public int Add(int val1, int val2, out string[] outputz)
    {
        int total = val1 + val2;
        outputz = new string[5];
        outputz[1] = "test2";
        outputz[2] = "test3";
        outputz[3] = "test4";
        outputz[4] = "test5";
        return total;
    }


}
}

Next i did the usual, build, ran: gacutil & RegAsm

and in my classic asp page i had this:-

Dim params  
dim objPassport3
set objPassport3 = Server.CreateObject("LMS.Calc")
comTest2 = objPassport3.Add(1,1,params)

and i get error:

Error Type: Microsoft VBScript runtime (0x800A0005) Invalid procedure call or argument: 'Add' /eduservice/test.asp, line 25

But if i modify the assembly not to use an array, it all just work, i can even send normal string or int to and from the assembly to classic asp. i read so many things but i get the same error,

anyone tried this before and was successful, please do share your solution

thanks

D'Arcy Rittich · Accepted Answer · 2009-08-31 14:05:46Z

10

ASP can only handle arrays that are variant, rather than arrays of strings or ints. So try using an object instead, e.g.,

public int Add(int val1, int val2, out object outputz)
{
    int total = val1 + val2;
    outputz = new object[5]
      {
          "test1",
          "test2",
          "test3",
          "test4",
          "test5"
      };

    return total;
}

answered Aug 31, 2009 at 14:05

D'Arcy Rittich

172k41 gold badges298 silver badges287 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

visual Over a year ago

thanks so much for the reply...cant wait to try..will update you on the status

visual Over a year ago

OrbMan, thanks, you solved my problem, wish i could treat you for lunch.

obsoleter Over a year ago

This is the same for VBScript. Even though you can CreateObject complex types exposed through COM from VBScript, you cannot pass them back into a method from a .NET assembly unless the complex parameters of that method are of type object. Primitives (e.g., string, int, etc.) are fine.

Collectives™ on Stack Overflow

COM Interop (how to pass an array to the com) via classic ASP

1 Answer 1

3 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related