Release COM+ object

Question

I have COM+ server component written in C# that is consumed by a C# WPF client, All the COM components are registered on the Client machine, I am able to create an instance of COM component and call the methods but after i am done with i am not able
to dispose it.
COM+ class:
    using System;
    using System.EnterpriseServices;
    using System.Runtime.InteropServices;
    namespace Mdrx.PM.Server.Lookup.Svr
        [EventTrackingEnabled(true)]
        [Guid("999999-A351-4AF9-AAFE-931549FD6EFA")]
        [ProgId("foo.PM.Server.Lookup.Svr.LkpQueryPat")]
        [Transaction(TransactionOption.Supported)]
        public class LkpQueryPat : ServicedComponent, IQuery
            public LkpQueryPat();
            public int Query(dynamic vntToken, object vntIn, ref object vntData, ref int lngErrorID);
I have compile time reference to this assembly in my client project so i am able to directly instantiate an object. I try to use Marshal.ReleaseComObject but that throws exception:
The object's type must be __ComObject or derived from __ComObject  
    LkpQueryPat patientLookupQuery = new LkpQueryPat();
    patientLookupQuery = null;
On the server i can see under dcomcnfg that the object remains under In Call column and never goes away, even if i kill the client application.
I noticed one more thing Objects column is the number of references client is holding and in my case it is 0 and that is because of these 2 lines, if i remove these then that number also keep increasing.
http://msdn.microsoft.com/en-us/library/windows/desktop/ms681593%28v=vs.85%29.aspx
(patientLookupQuery as System.EnterpriseServices.ServicedComponent).Dispose();
patientLookupQuery = null;
What i don't understand is what the In Call column and how can bring that number to 0.
    

Answer 1

My class is very simple, It has all the typical COM realted attributes applied to the class and it has one public method:
public interface IGetFeatureToggles
List<Data.FeatureToggle> GetAllFeatureToggles(object[] token);
// List<Data.FeatureToggle> GetAllFeatureToggles(Token token);
/// <summary>
/// Class for retrieving Feature Toggles
/// </summary>
[ProgId("Mdrx.PM.Server.FeatureToggle.Svr.GetFeatureToggles")]
[Transaction(TransactionOption.Supported)]
[EventTrackingEnabled(true)]
[Guid("960D39FE-2792-44D7-AC2B-14CD7A1CB50F")]
public class GetFeatureToggles : ServicedComponent, IGetFeatureToggles
#region private members
#endregion
#region constructors
#endregion
#region public properties
#endregion
#region public methods
/// <summary>
/// Retrieves all Feature Toggles
/// </summary>
/// <param name="token">Object Array representing a Token</param>
/// <returns>List of FeatureToggle</returns>
[AutoComplete]
public List<Data.FeatureToggle> GetAllFeatureToggles(object[] token)
IGetDbFeatureToggleAll getData = new GetFeatureToggleAll();
var properToken = new Token(token);
var featureToggles = getData.GetFeatureToggleDataAll(properToken);
if (featureToggles != null && featureToggles.Count > 0)
var getUserAccess = new GetFeatureToggleUserAccessByFeatureToggleId();
foreach (var featureToggle in featureToggles)
featureToggle.UsersWithAccess = getUserAccess.GetUserAccessDataByFeatureToggleId(properToken, featureToggle.FeatureToggleID);
return featureToggles;
#endregion
#region private methods
#endregion
This class is registered on the client machine, I am adding a reference to the DLL, I need to the add the reference to my project because when i try to create an instance of the class using Activator.CreateInstance and the DLL is not there it gives in File
not found exception.
I am using this to get the type and create an instance;
var iGetFeatureToggles = _comServerFactory.GetComServer<IGetFeatureToggles>(typeof(GetFeatureToggles));
public T GetComServer<T>(string progId)
Type comType;
if (ComClientAssembliesManager.IsClientType(progId))
comType = Type.GetTypeFromProgID(progId, null);
else
string remoteServer = ConfigurationManager.AppSettings[RemoteComputerNameConfigKey];
//TODO: Analyze how to call DCOM object with "localhost" remote server name.
comType = Type.GetTypeFromProgID(
progId,
string.IsNullOrWhiteSpace(remoteServer) || remoteServer == "localhost" ? null : remoteServer);
return (T)Activator.CreateInstance(comType);