COM Discussion Boards

Re: Need help using object in ATL ActiveX EXE window services server.

pba_23-Dec-02 12:41

23-Dec-02 12:41

You will need to overwrite CServiceModule::Run - after the service will register the class objects, init your object and call the method. After the message loop sequence, destroy your object.

Re: Need help using object in ATL ActiveX EXE window services server.

bahruddina23-Dec-02 19:14

bahruddina

23-Dec-02 19:14

hi,

thanx for ur replay Smile | :)

I've change my code. But when I try to start my service I got an error :

Could not start the Test on Local Computer.
Error 1053: The service did not respond to the start or control request
in a timely fashion.

And one more thing; how i want to destroy the ATL object in a correct way:

m_Obj->Release()

or

m_Obj = NULL

Below is code for CServiceModule::Run() :

void CServiceModule::Run() { _Module.dwThreadID = GetCurrentThreadId(); HRESULT hr = CoInitialize(NULL); // If you are running on NT 4.0 or higher you can use the following call // instead to make the EXE free threaded. // This means that calls come in on a random RPC thread // HRESULT hr = CoInitializeEx(NULL, COINIT_MULTITHREADED); _ASSERTE(SUCCEEDED(hr)); // This provides a NULL DACL which will allow access to everyone. CSecurityDescriptor sd; sd.InitializeFromThreadToken(); hr = CoInitializeSecurity(sd, -1, NULL, NULL, RPC_C_AUTHN_LEVEL_PKT, RPC_C_IMP_LEVEL_IMPERSONATE, NULL, EOAC_NONE, NULL); _ASSERTE(SUCCEEDED(hr)); hr = _Module.RegisterClassObjects(CLSCTX_LOCAL_SERVER | CLSCTX_REMOTE_SERVER, REGCLS_MULTIPLEUSE); _ASSERTE(SUCCEEDED(hr)); <big>// //create an ATL object // CComObject<CMyObj> *m_Obj; CComObject<CMyObj>::CreateInstance(&m_Obj);</big> <big>// //call object method // m_Obj->CallMe();</big> LogEvent(_T("Service started")); if (m_bService) SetServiceStatus(SERVICE_RUNNING); MSG msg; while (GetMessage(&msg, 0, 0, 0)) DispatchMessage(&msg); <big>// //free the object; I'm not sure wether to use m_Obj->Release() or m_Obj = NULL // m_Obj->Release();</big> _Module.RevokeClassObjects(); CoUninitialize(); }

Below is code for CMyObj :

HRESULT CMyObj::FinalConstruct() { return S_OK; } void CMyObj::FinalRelease() { } <big>STDMETHODIMP CMyObj::CallMe() { MessageBox(NULL, "Window services called me.", "MyObj", MB_OK); return S_OK; }</big>

Sorry for the silly questions. Smile | :)

Thanx in advance.

Regards.

Re: Need help using object in ATL ActiveX EXE window services server.

pba_24-Dec-02 4:28

pba_

24-Dec-02 4:28

NT Services are running into a window station which is not interactive, so they cannot have a user interface - your service will be blocked at MessageBox call from CallMe method. Try to write something to the debug output instead. To release the object call Release ( setting the smart ptr to NULL will NOT dereference the object), or use CComObjectStack instead of CComObject, since your object is used only in Run method.
ps. If you really want, you can change your service to interact with the active desktop ( to have a user interface ), by using service_interactive flag when you call CreateService.

Re: Need help using object in ATL ActiveX EXE window services server.

geo_m30-Dec-02 5:56

geo_m

30-Dec-02 5:56

Or if you really want to use the messagebox inside the service, really only for debugging purposes or something like that, you can use the MB_SERVICE_NOTIFICATION flag for the messagebox function

<br />
MessageBox( NULL, "some message", NULL, MB_OK | MB_SERVICE_NOTIFICATION );<br />

This will pop-up the message box on the default desktop.

Assigining a NULL value to the smart pointer is also a correct way of releasing the pointer - if you look into the implementation of CComPtr, it will first call release on currently assigned pointer and then attaches to the new one. This is a must for correctly working = operator, so I guess it is valid for each com smart pointer. Then if you assign NULL, it will first call the Release and then stores your NULL value.

Re: Need help using object in ATL ActiveX EXE window services server.

pba_30-Dec-02 6:03

pba_

30-Dec-02 6:03

You are right - assigning NULL to a CComPtr instance will dereference the contained interface. Thanks!

Re: Need help using object in ATL ActiveX EXE window services server.

bahruddina30-Dec-02 20:28

bahruddina

30-Dec-02 20:28

hi,

When I call m_Obj->Release() or m_Obj = NULL; my FinalRelease() never called Frown | :(

void CServiceModule::Run()<br />
{<br />
    _Module.dwThreadID = GetCurrentThreadId();<br />
<br />
    HRESULT hr = CoInitialize(NULL);<br />
//  If you are running on NT 4.0 or higher you can use the following call<br />
//  instead to make the EXE free threaded.<br />
//  This means that calls come in on a random RPC thread<br />
//  HRESULT hr = CoInitializeEx(NULL, COINIT_MULTITHREADED);<br />
<br />
    _ASSERTE(SUCCEEDED(hr));<br />
<br />
    // This provides a NULL DACL which will allow access to everyone.<br />
    CSecurityDescriptor sd;<br />
    sd.InitializeFromThreadToken();<br />
    hr = CoInitializeSecurity(sd, -1, NULL, NULL,<br />
        RPC_C_AUTHN_LEVEL_PKT, RPC_C_IMP_LEVEL_IMPERSONATE, NULL, EOAC_NONE, NULL);<br />
    _ASSERTE(SUCCEEDED(hr));<br />
<br />
    hr = _Module.RegisterClassObjects(CLSCTX_LOCAL_SERVER | CLSCTX_REMOTE_SERVER, REGCLS_MULTIPLEUSE);<br />
    _ASSERTE(SUCCEEDED(hr));<br />
<br />
	CComObject<CMyObj> *m_Obj;<br />
	CComObject<CMyObj>::CreateInstance(&m_Obj);<br />
<br />
	m_Obj->CallMe();<br />
<br />
    LogEvent(_T("Service started"));<br />
    if (m_bService)<br />
        SetServiceStatus(SERVICE_RUNNING);<br />
<br />
    MSG msg;<br />
    while (GetMessage(&msg, 0, 0, 0))<br />
        DispatchMessage(&msg);<br />
<br />
        <big>//FinalRelease is not triggered<br />
	m_Obj->Release();</big> <br />
<br />
    _Module.RevokeClassObjects();<br />
<br />
    CoUninitialize();<br />
}<br />

Below is .h code for CMyObj :

<br />
// MyObj.h : Declaration of the CMyObj<br />
<br />
#ifndef __MYOBJ_H_<br />
#define __MYOBJ_H_<br />
<br />
#include "resource.h"       // main symbols<br />
<br />
/////////////////////////////////////////////////////////////////////////////<br />
// CMyObj<br />
class ATL_NO_VTABLE CMyObj : <br />
	public CComObjectRootEx<<CComSingleThreadModel>>,<br />
	public CComCoClass<<CMyObj, &CLSID_MyObj>>,<br />
	public IDispatchImpl<<IMyObj, &IID_IMyObj, &LIBID_TESTLib>><br />
{<br />
public:<br />
	CMyObj()<br />
	{<br />
	}<br />
<br />
	HRESULT FinalConstruct()<br />
	{<br />
		MessageBox(NULL, "Start", NULL, MB_OK | MB_SERVICE_NOTIFICATION );<br />
		return S_OK;<br />
	}<br />
<br />
	<big><br />
        //this never get called when Release() or NULL executed<br />
        void FinalRelease()<br />
	{<br />
		MessageBox(NULL, "stop", NULL, MB_OK | MB_SERVICE_NOTIFICATION);<br />
	}</big><br />
<br />
DECLARE_REGISTRY_RESOURCEID(IDR_MYOBJ)<br />
<br />
DECLARE_PROTECT_FINAL_CONSTRUCT()<br />
<br />
BEGIN_COM_MAP(CMyObj)<br />
	COM_INTERFACE_ENTRY(IMyObj)<br />
	COM_INTERFACE_ENTRY(IDispatch)<br />
END_COM_MAP()<br />
<br />
// IMyObj<br />
public:<br />
	STDMETHOD(CallMe)();<br />
};<br />
<br />
#endif //__MYOBJ_H_<br />

Thanx in advance Smile | :)

Regards.

packaging a vc++ software?

xxhimanshu21-Dec-02 1:40

xxhimanshu

21-Dec-02 1:40

hi all,

i am stuck.please help. my problem is I want to make a setup program for my vc++ application as we have in VB.can anyone help me out?

thanks in advance
regards

Himanshu

Re: packaging a vc++ software?

Renjith Ramachandran29-Dec-02 6:00

Renjith Ramachandran

29-Dec-02 6:00

hey
use the SMS installer 16/32

~~~~Code the Dreams~~~~~

ATL COM thingie using inheritance

Scracha20-Dec-02 4:56

Scracha

20-Dec-02 4:56

Is it possible for a COM Class I've made using the ATL Wizard thingie to inherit from another class.

The following code doesn't compile since I added "public INewParentClass", I get the following error on the COM_INTERFACE_ENTRY(IDispatch) line.

c:\temp\code\mymethod2\mymethod.h(29) : error C2594: 'static_cast' : ambiguous conversions from 'class CMYMETHOD *' to 'struct IDispatch *'

Code is as follows.

/////////////////////////////////////////////////////////////////////////////
// MYMETHOD.h : Declaration of the CMYMETHOD

#ifndef __MYMETHOD_H_
#define __MYMETHOD_H_
#include "resource.h" // main symbols
#include "IParentClass.h"

/////////////////////////////////////////////////////////////////////////////
// CMYMETHOD
class ATL_NO_VTABLE CMYMETHOD :
public CComObjectRootEx<ccomsinglethreadmodel>,
public CComCoClass<cmymethod, &clsid_mymethod="">,
public IDispatchImpl<ivpim, &iid_imymethod,="" &libid_mymethodserver2lib="">,
public INewParentClass
{
public:
CMYMETHOD()
{
}

DECLARE_REGISTRY_RESOURCEID(IDR_MYMETHOD)

DECLARE_PROTECT_FINAL_CONSTRUCT()

BEGIN_COM_MAP(CMYMETHOD)
COM_INTERFACE_ENTRY(IMYMETHOD)
COM_INTERFACE_ENTRY(IDispatch)
END_COM_MAP()

// IMYMETHOD
public:
STDMETHOD(Hello)(/*[in]*/ BSTR sClientName);
};

#endif //__MYMETHOD_H_

Re: ATL COM thingie using inheritance

Ranjan Banerji20-Dec-02 5:44

Ranjan Banerji

20-Dec-02 5:44

Yes it is possible. Not sure what the cause of the error is, but most likely it is coming from something in INewParentClass. An ATL based class can inherit from a regular C++ class, not another ATL class.

Re: ATL COM thingie using inheritance

pba_23-Dec-02 12:30

pba_

23-Dec-02 12:30

Probably INewParentClass is inherited from IDispatchImpl too.

Beginners help with SAFEARRAY

Obliterator19-Dec-02 8:24

Obliterator

19-Dec-02 8:24

Hi all,

I have what seems to be a trivial problem...
I need to convert an array of doubles to a SAFEARRAY**

i.e. I have:
double MyArray[50];

I need to pass this to a third part function as a SAFEARRAY**

I'm sure this is a doddle - but I just keep crashing it with what I pass.
I'm new to all this COM stuff... why does it have to be so complicated?!

Thanks

--

The Obliterator

Re: Beginners help with SAFEARRAY

Barry Lapthorn19-Dec-02 20:47

Barry Lapthorn

19-Dec-02 20:47

Something like this should help:

SAFEARRAY* CFoo::DoubleArrayToSafeArray(double* array, int n)<br />
{<br />
        // n is the size of the array.<br />
        // caller takes ownership of returned SAFEARRAY<br />
<br />
        // create array bounds.<br />
	SAFEARRAYBOUND rgsabound[1];<br />
	rgsabound[0].lLbound = 0;<br />
	rgsabound[0].cElements = n;<br />
<br />
        //  create safearray<br />
	SAFEARRAY* pReturn = NULL;<br />
	pReturn = SafeArrayCreate( VT_R8 , 1, rgsabound);<br />
<br />
	if (pReturn == NULL)<br />
		return pReturn;<br />
<br />
        //  populate it<br />
	long idxPos = 0;<br />
	for (idxPos = 0 ; idxPos < n; idxPos++)<br />
	{<br />
	  HRESULT hr = SafeArrayPutElement(pReturn, &idxPos, (void*) &(array[idxPos]));<br />
	}<br />
	return pReturn;<br />
}

Regards

Barry

Re: Beginners help with SAFEARRAY

work_to_live20-Dec-02 20:18

work_to_live

20-Dec-02 20:18

Barry,
Can you point me to a good overview on the use of SafeArrays and Variants?

Thanks.

Re: Beginners help with SAFEARRAY

Barry Lapthorn22-Dec-02 0:37

Barry Lapthorn

22-Dec-02 0:37

I spent ages trawling through MSDN I'm afraid. Frown | :(

I would imagine that there are some articles on safearrays and variants here on CodeProject as well. Big Grin | :-D

Regards

Barry

Re: Beginners help with SAFEARRAY

Barry Lapthorn23-Dec-02 3:16

Barry Lapthorn

23-Dec-02 3:16

Try:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnguion/html/drgui032999.asp[^]

and

http://support.microsoft.com/support/kb/articles/Q167/6/68.ASP[^]

Regards

Barry

a COM+ design question

Anonymous19-Dec-02 3:16

Anonymous

19-Dec-02 3:16

I want to design a card game ,use Com+ server.
But when 4 clients connected,it's created 4 com+ instance in server,
so it's hard to manage.
I want to know :
how I can connect every 4 clients to 1 com+ instance in server.

Re: a COM+ design question

Burt Harris21-Dec-02 10:34

Burt Harris

21-Dec-02 10:34

Hi Anonymous,

I'm not sure use of COM+ for this is a good match betwen your problem and the platform. You might want to take a look at DirectPlay http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dx8_c/directx_cpp/Play/DPlay.asp[^] which is specifically designed for multi-player games.

Burt Harris

Got CLSID/PROGID, how to access?

Anonymous19-Dec-02 1:25

Anonymous

19-Dec-02 1:25

Hi,

I've got a CLSID for a COM object in a C++ program, how do I access methods on this object. Do I have to call QueryInterface() somehow?

I can do a CoCreateInstance() but that requires an interface ID. Assuming all I have is the CLSID, how do I do it?

Thanks!

Re: Got CLSID/PROGID, how to access?

Anonymous19-Dec-02 10:17

Anonymous

19-Dec-02 10:17

Try to QI for IUnknown or IDispatch

CLSID clsid;//some valid clsid
LPDISPATCH pDisp;
HRESULT hr = CoCreateInstance(clsid,NULL,CLSCTX_SERVER,IID_IDispatch,(LPVOID*)&pDisp);
if(SUCCEEDED(hr))
{
//now call interface methods
pDisp->AutomationCall();
}
}

Re: Got CLSID/PROGID, how to access?

geo_m30-Dec-02 6:16

geo_m

30-Dec-02 6:16

hmm, in fact, you can create the object, asking CoCreateInstance for IID_IUnknown as an Interface ID (IID). Then you will receive the pointer to the IUnknown.

But the question is what you want to do next - for nearly every other activity you will need to retrieve some interface from the object, else you will be able only to call IUnknown methods or might be IDispatch methods, but without any further info you are generally not able to perform any operation over that object.

I don't know if I expressed myself correctly, but the situation then is similar to having a .lib without header - so you have some objects inside the lib but you don't know how to talk to them.

What interface to implement to be a datasource to VB data bound control?

Erik Juhl13-Dec-02 5:47

Erik Juhl

13-Dec-02 5:47

I have created a COM collection object for use by our UI team, but now requirements seem to have changed and they no longer want COM collections but something like ADO recordsets they can bind to their grids. It seemed to me that a data bound control is probably just using an interface on the ADO recordset objects to navigate the collection. And since I already had my COM collection implemented, if I could implement this mysterious DataSource interface I could make everyone happy. Can anyone give me a push in the right direction? What interface do I need to implement in my COM collection to act as a DataSource for a VB Data Bound control? Thanks in advance.

Re: What interface to implement to be a datasource to VB data bound control?

Jörgen Sigvardsson24-Dec-02 12:46

Jörgen Sigvardsson

24-Dec-02 12:46

Take a look at the ATL OLEDB data producer classes¹. Many grids support OLEDB as well if I'm not mistaken..

Just fire up an ATL project, and add an OLEDB data producer class using the ATL wizard, and go on from there. Smile | :)

¹ I'm not sure this is the correct name. I'm 100 miles from home, so I can't lookup the name right now. But just look at the ATL wizards and you'll know it when you see it.

--
Only in a world this sh*tty could you even try to say these were innocent people and keep a straight face.

how to debug visual com dll ??

Leesen13-Dec-02 5:08

Leesen

13-Dec-02 5:08

hi,all
I write a COM Dll in Visual ATL . And I refer the COM dll in VB environment. The vb program runs well except when the program exit, the error dialog occur. The error info are such as "the address can't read ..." . Is it concerns with
the c++ pointer ??? But how can I find the actuall false??

Are there any tools to help to debug the com dll??
The problem disturb me for very long time .

Ask for your help , please !

Regards.

Re: how to debug visual com dll ??

geo_m13-Dec-02 11:29

geo_m

13-Dec-02 11:29

Best way is to load the ATL project to the MSVC and set up the visual basic as a startup exe. Then when you press f5, the VB will be started. You can work with the VB as you want, e.g. load some test project, but you can put the breakpoints to methods of your DLL and the execution will stop there in case it will be called...

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.