How to stop Delphi registering COM objects

Posted on 2003-02-20
Medium Priority
Last Modified: 2011-09-20
I am writing a DLL in Delphi that serves COM objects to a Python script.  Python is basically an interpreted language and accesses the COM objects using using IDispatch.  As far as I can tell, the only way to write IDispatch objects in Delphi is to write dual-interfaced automation objects.  I use File->New->ActiveX->Automation Object to create them because that's the only thing that seems to work for me.

Although the DLL provides many COM objects, I want the DLL to register only the top-level object (IServer).  The python script makes calls on IServer to get the other objects, so no registration is necessary for them.

Unfortunately, when I create automation objects as above, Delphi adds a TAutoObjectFactory.Create to the initialization section for every unit.  In consequence all the interfaces get registered.  I can't comment out this bit because it causes TAutoObject.Create to fail.  I suppose I could derive a new class factory from TAutoObjectFactor and the override the UpdateRegistry method to do nothing, but this seems ugly.  Surely there is a better way.

So my question is this: Is there a proper way to serve IDispatch interfaces in Delphi without Delphi attempting to register them?
Question by:oliverbock
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Expert Comment

ID: 7992131
You can do it other way:
New -> ActiveX -> ActiveX Library then
New -> ActiveX -> Type Library
then there will be no auto created COMs.
Or other way is:
New -> Unit
this unit should look like this:

unit UEntryPoint;


uses ComServ;

function DllGetClassObject(const CLSID, IID: TGUID; var Obj): HResult; stdcall;
function DllCanUnloadNow: HResult; stdcall;
function DllRegisterServer: HResult; stdcall;
function DllUnregisterServer: HResult; stdcall;


uses AddIn, webdcsrvtool_TLB, ActiveX;

        S_OK    = $00000000;

function DllGetClassObject(const CLSID, IID: TGUID; var Obj): HResult;
  // do here custom DLL Load

function DllCanUnloadNow: HResult;
  // custom DLL UnLoad

function DllRegisterServer: HResult;
  //custom register

function DllUnregisterServer: HResult;
  // custom UnRegister


then go to project file and change ComServ with UEntryPoint.

Author Comment

ID: 8012807
While ziolko's comment shows me how to create a COM server that doesn't export anything, it doesn't solve my problem.  It doesn't tell me how to implement an IDispatch object that doesn't register itself.

Accepted Solution

oliverbock earned 0 total points
ID: 8023247
It turns out that there is a simple way to do this: select "Internal" as the Instancing type in the Automation Object Wizard.  (You get to this wizard when creating new automation objects via File->New->ActiveX->Automation Object)  This supplies the ciInternal flag to the TAutoObjectFactory constructor.

Expert Comment

ID: 9317147
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