Call Unmanaged Code from SSIS Script Task

Question

I have Business Intelligence -> Integration Services Project where I have SSIS Packages -> Script Task. I need to call from Script Task Unmanaged code using DllImport. Since I don't know where code for Script Task is stored during run-time I can't call my unmanaged dll.

Example code below for Script Task:

using System; // Console
using System.Runtime.InteropServices; // DllImport

class App
{
    [DllImport("lib.dll", CallingConvention = CallingConvention.Cdecl)]
extern static int next(int n);

    static void Main()
    {
       Console.WriteLine(next(0));
       Dts.TaskResult = (int)ScriptResults.Success;
    }
}

You can find more about Script Task here

Question: How to call Unmanaged Code from SSRS Package -> Script Task?

Answer 1

SSIS won't load dll's by location, even managed dll's. You have to GAC them, http://microsoft-ssis.blogspot.com/2011/05/referencing-custom-assembly-inside.html . I would therefore expect you to have to COM register your unmanaged dll, https://technet.microsoft.com/en-us/library/bb490985.aspx .

Answer 2

Make sure to copy c/c++ dll into " C:\\Program Files\\Microsoft SQL Server\\120\\DTS\\Binn " which will be loaded when managed code calls DllImport

NOTE: 120 is version specific make sure to copy to the correct version that you have.