I'm trying to pass an object as a parameter to a queued component.  I know
that the class needs to implement the IPersistStream interface, but I'm
still having problems.  First, I'm defining the IPersistStream interface in
my code as follows:

//Definition for interface IPersistStream.
[ComImport,
InterfaceType(ComInterfaceType.InterfaceIsIUnknown),
Guid("0000010c-0000-0000-C000-000000000046")]
public interface IPersist
{
void GetClassID( /* [out] */ out Guid pClassID);
};

[ComImport,
InterfaceType(ComInterfaceType.InterfaceIsIUnknown),
Guid("00000109-0000-0000-C000-000000000046")]
public interface IPersistStream : IPersist
{
new void GetClassID(out Guid pClassID);
[PreserveSig]
int IsDirty();
void Load([In] UCOMIStream pStm);
void Save([In] UCOMIStream pStm, [In, MarshalAs(UnmanagedType.Bool)] bool
fClearDirty);
void GetSizeMax(out long pcbSize);
};

Next, I define the class that I'm trying to pass as a parameter, and I
implement the IPersistStream methods

void IPersist.GetClassID(out Guid pClassID)
{
pClassID = Marshal.GenerateGuidForType( this.GetType());
}
void IPersistStream.GetClassID(out Guid pClassID)
{
pClassID = Marshal.GenerateGuidForType( this.GetType());
}
int IPersistStream.IsDirty()
{
log.WriteEntry(@"IMyPersistStreamImpl::IsDirty");
return m_bRequiresSave ? 0 : -1;
}
//called when instantiating the object from the stream.
unsafe void IPersistStream.Load([In] UCOMIStream pStm)
{
log.WriteEntry(@"IMyPersistStreamImpl::Load");
[... code omitted for brevity...]

}
//called when saving the object in the stream
unsafe void IPersistStream.Save([In] UCOMIStream pStm, [In,
MarshalAs(UnmanagedType.Bool)] bool fClearDirty)
{
log.WriteEntry(@"IMyPersistStreamImpl::Save");
[... code omitted for brevity...]

}
void IPersistStream.GetSizeMax(out long pcbSize)
{
log.WriteEntry(@"IMyPersistStreamImpl::GetSizeMax");
[... code omitted for brevity...]
}
Finally, I call my queued component, and I go look at the Event log.  I can
tell that none of the members of the IPersistStream interface have been
called, but I do find the following errors in the event log.

Object reference passed as a method parameter to a Queued Component does not
implement IPersistStream.IPersistStream::Save
and
Object reference passed as a method parameter to a Queued Component does not
implement IPersistStream.CMarshalInterceptor::GetSizeMax and Save

This, despite the fact that I have done my darndest to implement those very
methods!  I've been beating my head against the wall for a while now on
this, and I'm about to rewrite my code to pass all the arguments in as
individual primitive types, although it isn't as elegant.  However, I
thought I'd make one last try and see if anyone out there had any
suggestions.

By the way, I have tried both defining the methods that implement the
IPersistStream interface with the usual implicit interface syntax
e.g. public void GetSizeMax(out long pcbSize)

and with the explicit interface syntax
e.g. void IPersistStream.GetSizeMax(out long pcbSize)
It doesn't appear to make a difference one way or the other.

Oh yes, and I'm using Visual Studio.NET 2003, and Windows XP Professional,
although the components will eventually be deployed on Windows Server 2003.

Thanks for any suggestions...

Laura