on COM in .NET - COM Discussion Boards

25-Oct-04 4:04

I am developing a simple local COM server, after I finished building this server(compiled, ran), then I used the OLE/COM object viewer to check it (I am using VC6.00, and this OLE/COM object viewer is a tool provided in the IDE of VC6.0), I opened up the "All Objects", I can see the one that is inside my newly created local COM server, but when I clicked the "+" sign to open it more up, it says the following:

GetObject() failed,
The system cannot find the path speicifed, $80070003

Anyone knows what is this and what is reason??
Confused | :confused:

thanks!

Jörgen Sigvardsson25-Oct-04 8:38

Jörgen Sigvardsson

25-Oct-04 8:38

Did you remove the DLL file after it was registered? Take a look at the registry key HKEY_CLASSES_ROOT\CLSID\{your class' GUID}\InprocServer32 (assuming it's a DLL server). The default value of that key should be the path to your DLL. If it isn't, bingo, there's your problem. If the value is correct, then I can't really tell.

--
Weiter, weiter, ins verderben.
Wir müssen leben bis wir sterben.

liyang yu25-Oct-04 8:47

25-Oct-04 8:47

Thanks! In fact, I am using a EXE (local COM server) server, and the registry key looks like following:

HKEY_CLASSES_ROOT\CLSID\{myClassGUID}\LocalServer32 = somePath

so this part should be fine...

I appreciate your input very much though.

liyang

Jörgen Sigvardsson25-Oct-04 8:51

Jörgen Sigvardsson

25-Oct-04 8:51

Could it be that your COM server depends on a DLL (probably home made) which OLE/COM Viewer can't find? I can't remember if that fault produces the "file not found" error or "device not ready". In any case, the error code given is not intuitive. Unsure | :~

--
Weiter, weiter, ins verderben.
Wir müssen leben bis wir sterben.

liyang yu25-Oct-04 8:56

"Interface not registered" with win XP

25-Oct-04 8:56

not really. this is a very simple example, in fact it is a small lab example from this "Developer's Workshop to COM/ATL 3.0" book, and the author's own lab code also produces this problem. sigh..., and I cannot find his contact info.

on COM in .NET

ppp00125-Oct-04 1:21

ppp001

25-Oct-04 1:21

Hi all,

how can I create a COM in VC++.NET, which project template should I choose ?

Thanks
Patrick

sanouk24-Oct-04 22:19

sanouk

24-Oct-04 22:19

Hello,

I develop a COM Object wint IConnectionPoint. I have a method "Advise" with the line:
HRESULT hr = CoMarshalInterThreadInterfaceInStream(IID__IInterface_OutilsEvents, p, &m_StreamArray[m_nStreamIndex] );

It's ok with windows 2000 but when I try it with Windows XP, I have an error in this line:
"Interface not registered"

Why?

Thanks

Sanouk

Re: "Interface not registered" with win XP

geo_m19-Nov-04 3:27

geo_m

19-Nov-04 3:27

And is it registered? You can investigate by using OLE/COM object viewer if the interface is registered or not.

basic question about COM

liyang yu23-Oct-04 9:14

23-Oct-04 9:14

I am writing a very simple local COM server (exe), which has a Car class, a CarClassFactory, also a simple idl, everything goes well until the WinMain() file which provides the housing for the coclass and class factory, vC6.00 keeps saying the following:

Deleting intermediate files and output files for project 'CarCOMExe - Win32 Debug'.
--------------------Configuration: CarCOMExe - Win32 Debug--------------------
Creating Type Library...
Processing F:\COM\CarCOMExe\CarCOMExeTypeInfo.idl
CarCOMExeTypeInfo.idl
Processing F:\Microsoft Visual Development\Microsoft Visual Studio\VC98\INCLUDE\oaidl.idl
oaidl.idl
Processing F:\Microsoft Visual Development\Microsoft Visual Studio\VC98\INCLUDE\objidl.idl
objidl.idl
Processing F:\Microsoft Visual Development\Microsoft Visual Studio\VC98\INCLUDE\unknwn.idl
unknwn.idl
Processing F:\Microsoft Visual Development\Microsoft Visual Studio\VC98\INCLUDE\wtypes.idl
wtypes.idl
Compiling...
StdAfx.cpp
Compiling...
Car.cpp
CarClassFactory.cpp
CarCOMExe.cpp
f:\com\carcomexe\carclassfactory.h(13) : error C2504: 'IClassFactory' : base class undefined
f:\com\carcomexe\carclassfactory.h(19) : error C2061: syntax error : identifier 'REFIID'
f:\com\carcomexe\carclassfactory.h(25) : error C2061: syntax error : identifier 'LPUNKNOWN'
F:\COM\CarCOMExe\CarCOMExe.cpp(32) : error C2065: 'CoInitialize' : undeclared identifier
F:\COM\CarCOMExe\CarCOMExe.cpp(36) : error C2065: 'ITypeLib' : undeclared identifier
F:\COM\CarCOMExe\CarCOMExe.cpp(36) : error C2065: 'pTLib' : undeclared identifier
F:\COM\CarCOMExe\CarCOMExe.cpp(36) : error C2106: '=' : left operand must be l-value
F:\COM\CarCOMExe\CarCOMExe.cpp(37) : error C2065: 'LoadTypeLibEx' : undeclared identifier
F:\COM\CarCOMExe\CarCOMExe.cpp(37) : error C2065: 'REGKIND_REGISTER' : undeclared identifier
F:\COM\CarCOMExe\CarCOMExe.cpp(38) : error C2227: left of '->Release' must point to class/struct/union
F:\COM\CarCOMExe\CarCOMExe.cpp(48) : error C2065: 'CoRegisterClassObject' : undeclared identifier
F:\COM\CarCOMExe\CarCOMExe.cpp(48) : error C2065: 'IClassFactory' : undeclared identifier
F:\COM\CarCOMExe\CarCOMExe.cpp(48) : error C2059: syntax error : ')'
F:\COM\CarCOMExe\CarCOMExe.cpp(61) : error C2065: 'CoRevokeClassObject' : undeclared identifier
F:\COM\CarCOMExe\CarCOMExe.cpp(65) : error C2065: 'CoUninitialize' : undeclared identifier
locks.cpp
Generating Code...
Error executing cl.exe.
Creating browse info file...

CoCarEXE.exe - 15 error(s), 0 warning(s)

as you can sees, it keeps saying that IClassFactory is undefined, but the CarClassFactory.cpp compiles well. CarClassFactory.h is very simple:

#define CarClassFactory_H

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

#include <windows.h>

class CarClassFactory : public IClassFactory
{
public:
	CarClassFactory();
	virtual ~CarClassFactory();

	// IUnknown
	STDMETHODIMP QueryInterface(REFIID riid,void** pIFace);
	STDMETHODIMP_(ULONG)AddRef();
	STDMETHODIMP_(ULONG)Release();

	// IClassFactory
	STDMETHODIMP LockServer(BOOL fLock);
	STDMETHODIMP CreateInstance(LPUNKNOWN pUnkOuter,REFIID riid,void** ppv);

private:

	ULONG m_refCount;

};
#endif

and CarCOMExe.cpp is as follows:

#include "stdafx.h"
#include "CarCOMExeTypeInfo_i.c"	// MIDL file
#include "CarClassFactory.h"		// MIDL file
#include <string.h>


// Our global counter for locks & active objects.
DWORD g_allLocks;


int APIENTRY WinMain(HINSTANCE hInstance,
                     HINSTANCE hPrevInstance,
                     LPSTR     lpCmdLine,
                     int       nCmdShow)
{
	// Init COM.
	CoInitialize(NULL); 	

	// Let's register the type lib.
	// to get the 'free' type library marsahler.
	ITypeLib* pTLib = NULL;
	LoadTypeLibEx(L"CarCOMExeTypeInfo.tlb", REGKIND_REGISTER, &pTLib);
	pTLib->Release();
	
	// Let's see if we were started by SCM.
	if(strstr(lpCmdLine, "/Embedding") || strstr(lpCmdLine, "-Embedding"))
	{
		// Create the Car class object.
		CarClassFactory carClassFactory;

		// Register the Car Factory.
		DWORD regID = 0;
		CoRegisterClassObject(CLSID_Car, (IClassFactory*)&carClassFactory, 
							  CLSCTX_LOCAL_SERVER, REGCLS_MULTIPLEUSE, ®ID);

		// Now just run until a quit message is sent,
		// in responce to the final release.
		MSG ms;
		while(GetMessage(&ms, 0, 0, 0))
		{
			TranslateMessage(&ms);
			DispatchMessage(&ms);
		}

		// All done, so remove class object.
		CoRevokeClassObject(regID);	
	}

	// Terminate COM.
	CoUninitialize();	
	MessageBox(NULL, "Server is dying", "EXE Message!", MB_OK | MB_SETFOREGROUND);
	return 0;
}

Really frustrated, can some one give me some help?

Thanks!!

Anonymous23-Oct-04 16:00

Anonymous

23-Oct-04 16:00

Have you #included the following file into your program?

#include <windows.h>

-John

liyang yu23-Oct-04 16:38

23-Oct-04 16:38

yes, I did...

liyang yu23-Oct-04 16:40

Re: basic question about COM - the answer is here!!

23-Oct-04 16:40

Yes,I did. In fact, I did the following:

#include "stdafx.h"

which includes windows.h.

liyang yu23-Oct-04 17:14

Re: basic question about COM - the answer is here!!

23-Oct-04 17:14

It took me a day to figure this out:

I am using VC 6.00, and my

stdafx.h looks like this:<br />
<br />
<pre>
#if !defined(AFX_STDAFX_H__A9DB83DB_A9FD_11D0_BFD1_444553540000__INCLUDED_)
#define AFX_STDAFX_H__A9DB83DB_A9FD_11D0_BFD1_444553540000__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

#define WIN32_LEAN_AND_MEAN		// Exclude rarely-used stuff from Windows headers

#include <windows.h>


// TODO: reference additional headers your program requires here

//{{AFX_INSERT_LOCATION}}
// Microsoft Visual C++ will insert additional declarations immediately before the previous line.

#endif // !defined(AFX_STDAFX_H__A9DB83DB_A9FD_11D0_BFD1_444553540000__INCLUDED_)
</pre><br />
<br />
you need to get rid of <pre>#define WIN32_LEAN_AND_MEAN</pre> to make a simple local COM server work!!<br />
<br />
Thanks!

User 21559725-Oct-04 19:59

User 215597

25-Oct-04 19:59

Are u using ATL???

-------------------------
Have a great day ahead!
Regards,
Sohail Kadiwala
(My COM Blog - http://lovecom.blogspot.com)

modified 21-Apr-21 21:01pm.

Re: basic question about COM - the answer is here!!

liyang yu26-Oct-04 8:18

26-Oct-04 8:18

no, plain COM.