regsvr32 fails for simple freepascal COM dll

Question

I'm completely new to free-pascal and I try to implement a simple dll that should register a COM class. Unfortunately I could only find little information about COM Programming for freepascal. Thus I hope that someone here can give me some hints or even a link to some examples.

So here is what I did:

• my operating system is Windows 7 64 bit
• downloaded and installed Lazarus 32bit version
  • Version #: 1.2.6
  • Date: 2014-10-11
  • FPC: Version 2.6.4
  • SVN Revision: 46529
  • i386-win32-win32/win64
• installed the ActiveX package in Lazarus
• made a new project - type Library with a simple TAutoObject and a default TAutoObjectFactory for the COM registration: source code included after this description
• build the dll
• use regsvr32.exe to register my dll --> this fails with

  "make sure the binary is stored at the specified path ..."
  Invalid access to memory location.

• then I tried to change the default project options:
  under Compiler Options - Config and Target, I set
  • Target OS: Win32
  • Target CPU family: i386
• still the same error occurs

Project source

library LazarusSimpleComRegTest;

{$mode objfpc}{$H+}

uses
  Classes,
  { you can add units after this }
  ComServ, MyComObj;

exports
  DllGetClassObject,
  DllCanUnloadNow,
  DllRegisterServer,
  DllUnregisterServer;

end.           

MyComObj Unit:

unit MyComObj;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils, ComObj;

const
  CLASS_Plugin: TGUID = '{5E020FB0-B593-4ADF-9288-801C2FD432CF}';

type
  TPlugin = class(TAutoObject)

  end;

implementation

uses ComServ;

initialization
  TAutoObjectFactory.Create(ComServer, TPlugin, CLASS_Plugin,
    ciMultiInstance, tmApartment);

end.

Answer 1

I think the main problem was, that I did not include the type library as a resource in my dll file: Now it works fine.

I've made a very basic and simple working example on git-hub with some basic documentation: lazarus-com-example