wcf - Error in exposing c# DLL to VB6 -

i ask how exposed c# dll vb6. purpose of exposing dll consume wcf service vb6 application since cant consume directly wcf service.

below code in c#

[guid("116cca1e-7e39-4515-9849-90790da6431e")] [classinterface(classinterfacetype.none),comsourceinterfaces(typeof(itestbillerv10service))] [comvisible(true)] public class testbillerv10 : itestbillerv10service {     testbillerinquiry.testbillerinquiryclient _testbillerinquiry;      public testbillerv10()     {         _testbillerinquiry = new testbillerinquiry.testbillerinquiryclient();         system.net.servicepointmanager.expect100continue = false;     }      /// <summary>     /// inquire if account no valid or not     /// </summary>     /// <param name="accountno">account no. check</param>     /// <param name="userid">user id of terminal</param>     /// <returns>string array index[0] = response code(yes/no), index[1] = description response, index[2] = error code if response code no</returns>     [comvisible(true)]     [dispid(1)]     public string[] inquiry(string accountno, string userid)     {         var newinquiry = new testbillerinquiry.testbillerinquiryrequest {accountnumber = accountno, userid= userid };         testbillerinquiry.testbillerinquiryresponse response = _testbillerinquiry.inquiry(newinquiry);         var retval = new string[3];         retval[0] = response.response;         retval[1] = response.message;         retval[2] = response.error;         return retval;     } } 

and simple interface below

/// <summary>     /// inquire if account no valid or not     /// </summary>     /// <param name="accountno">account no. check</param>     /// <param name="userid">user id of terminal</param>     /// <returns>string array index[0] = response code(yes/no), index[1] = description response, index[2] = error code if response code no</returns>     [comvisible(true)]     public interface itestbillerv10service     {         [dispid(1)]         string[] inquiry(string accountno, string userid);     } 

below how try consume on vb6 returns

runtime erro 429 says acvtive x component cant create object.

dim testbillerv10 v10bridge.testbillerv10 set testbillerv10 = new testbillerv10 

try 2 changes. first class needs progid attribute (and don't use comsourceinterfaces got rid of it):

[guid("116cca1e-7e39-4515-9849-90790da6431e")] [classinterface(classinterfacetype.none)] [comvisible(true)] [progid("mynamespace.testbillerv10")] public class testbillerv10 : itestbillerv10service 

your interface needs guid , interfacetype:

[guid("782ab14d-be28-4b47-9498-dff94b457e6d")] [interfacetype(cominterfacetype.interfaceisidispatch)] [comvisible(true)] public interface itestbillerv10service