force two managed components to communicate through the com interop layer

Question

hi all.

i have two .net components that need to communicate using a com interface.  each component has its own declaration of that interface.

this seemed to be exactly what i needed:

http://blogs.msdn.com/b/jmstall/archive/2009/07/09/icustomqueryinterface-and-clr-v4.aspx

...but i can't get this sample to work.  does anyone know how to fix this problem?

Answer 1

Hi Jhail,

Welcome to the MSDN Forum.

What problem have you encountered?

Would you like to post your project here?

Best regards,

---

Mike Feng
MSDN Community Support | Feedback to us
Please remember to mark the replies as answers if they help and unmark them if they provide no help.

Answer 2

the problem is that the linked sample doesn't work.

Answer 3

Hi Jhail,

There is some code snippet in that blog, would you like to post your project here?

I look forward you.

Best regards,

---

Mike Feng
MSDN Community Support | Feedback to us
Please remember to mark the replies as answers if they help and unmark them if they provide no help.

Answer 4

The blog ends with a complete sample application.  I'll reproduce it below:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;

namespace ConsoleApplication4
{
    [ComImport, InterfaceType(1), ComConversionLoss, Guid("FC3E287D-D659-4E1D-81D5-9D29398C7237")]
    interface IFoo1
    {
        [PreserveSig]
        int Thing(int x);
    }

    [ComImport, InterfaceType(1), ComConversionLoss, Guid("FC3E287D-D659-4E1D-81D5-9D29398C7237")]
    interface IFoo2
    {        
        void Thing(int x);
    }


    class C1 : IFoo1, ICustomQueryInterface
    {

        static readonly Guid IID_IMarshal = new Guid("00000003-0000-0000-C000-000000000046");
        static readonly Guid IID_IManagedObject = new Guid("C3FCC19E-A970-11d2-8B5A-00A0C9B7C9C4");

        CustomQueryInterfaceResult ICustomQueryInterface.GetInterface(ref Guid iid, out IntPtr ppv)
        {
            if (iid == IID_IMarshal ||
                iid == IID_IManagedObject
                )
            {
                ppv = IntPtr.Zero;
                return CustomQueryInterfaceResult.Failed;
            }

            ppv = IntPtr.Zero;
            return CustomQueryInterfaceResult.NotHandled;
        }



        #region IFoo1 Members

        public int Thing(int x)
        {
            Console.WriteLine("Inside C1={0}", x);
            return 0;
        }

        #endregion
    }


   
    class Program
    {
        // Convert it to a RCW
        static object GetRCW(object o)
        {
            IntPtr ip = IntPtr.Zero;
            try
            {
                ip = Marshal.GetIUnknownForObject(o);
                return Marshal.GetObjectForIUnknown(ip);
            }
            finally
            {
                Marshal.Release(ip);
            }
        }

        static void Main(string[] args)
        {
            Console.WriteLine("Hi!");

            object c1 = new C1();
            object obj = GetRCW(c1);

            Console.WriteLine(c1.GetType().FullName); // ConsoleApplication4.C1
            Console.WriteLine(obj.GetType().FullName); // System.__ComObject

            IFoo1 f1 = (IFoo1)obj;
            IFoo2 f2 = (IFoo2)obj;
            f1.Thing(5);
            f2.Thing(3);
        }
    }
}

Answer 5

The exception message?

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Ghost,
Call me ghost for short, Thanks
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