Re: How can i call COM DLL in vc++ 2005? - COM Discussion Boards

27-Dec-06 22:51

Hi all,

How can i call the com based dll file to my vc++ MFC project.

And i am having one com based DLL,which is only the dll file(like eg. comgs.dll) there is no .h file and .lib file then how can i use it.

Please send any cleared article URL.

Thankx in Advance....

Currently i am using Microsoft Visual studio 2005.

Sakthiu27-Dec-06 23:40

Sakthiu

27-Dec-06 23:40

you want to use that COM dll .. right ?

then you have to register that COM dll in to your system.

To do that pres 'Start' button take 'Run' Applicaiotn, inside Run win type 'Regsvr32' then space your COM dll file location.

for example., you COM file location is C:\\app.dll then

in Run window, type 'regsvr32 c:\\app.dll' press enter

now your COM dll is register wit your system.

then write COM client program using api's like CoInitialize(NULL),CoCreateInsatnce() and CoUninitialize();

This is the way you have to use COM dll.

bye.

$uresh $hanmugam28-Dec-06 1:40

28-Dec-06 1:40

Hi Sakthiu,

That's fine, i have registered successfully but, i didn't know how to used to the client application. i didn't find good and cleared articles.

some articles tells that

AfxOleInit() - COM Initialize.

AfxOleTerm() - COM Uninitialize.

i have really confused. please send any cleared article URL or any sample code...

Thankx...

prasad_som28-Dec-06 1:54

28-Dec-06 1:54

This[^] article should give you idea, how you need to use COM interface.

Prasad
Notifier using ATL | Operator new[],delete[][^]

$uresh $hanmugam28-Dec-06 23:44

28-Dec-06 23:44

Hi Prasad,

I had read ur article.It's really usefull for me...

I followed correctly through ur sending article and successfully loading my dll,
but when i clicked the OK button,
1) MessageBox within "s" message and
2) MessageBox within "Failed" message showned and
3) assertion failed would be throwned.
my source code look like this...

void Ctest2_vcDlg::OnBnClickedOk()

{

// TODO: Add your control notification handler code here

CString s1,s2,s3;

s1=_T("c:\\p1.pdf");

s2=_T("c:\\pppp.jpg");

s3=_T("jpeg");

BSTR b1,b2,b3;

b1=s1.AllocSysString();

b2=s2.AllocSysString();

b3=s3.AllocSysString();

typedef HRESULT (WINAPI *pMakeFile) (BSTR,BSTR,BSTR);

pMakeFile MakeFile;

HMODULE hDll=LoadLibrary(_T("comgs.dll"));

if(hDll)

{

AfxMessageBox(_T("S"));

MakeFile = (pMakeFile)GetProcAddress(hDll,"MakeFile");

if(!MakeFile)

{

AfxMessageBox(_T("Failed"));

}

ATLASSERT(MakeFile);

MakeFile(b1,b2,b3);

FreeLibrary(hDll);

}

else

{

AfxMessageBox(_T("DLL Err"));

ATLASSERT(0);

}

OnOk()
}

And comgs library .tlh file look like this....

// Created by Microsoft (R) C/C++ Compiler Version 14.00.50727.42 (931fd62f).

//

// e:\sureshshanmugam\psudocodes\test2_vc\debug\comgs.tlh

//

// C++ source equivalent of Win32 type library comgs.dll

// compiler-generated file created 12/29/06 at 11:26:07 - DO NOT EDIT!

#pragma once

#pragma pack(push, 8)

#include <comdef.h>

namespace COMGSLib {

//

// Forward references and typedefs

//

struct __declspec(uuid("7a474480-a013-11d3-9c8b-00e098055175"))

/* LIBID */ __COMGSLib;

struct /* coclass */ gscript;

struct __declspec(uuid("7a47448c-a013-11d3-9c8b-00e098055175"))

/* dual interface */ Igscript;

//

// Smart pointer typedef declarations

//

_COM_SMARTPTR_TYPEDEF(Igscript, __uuidof(Igscript));

//

// Type library items

//

struct __declspec(uuid("7a47448d-a013-11d3-9c8b-00e098055175"))

gscript;

// [ default ] interface Igscript

struct __declspec(uuid("7a47448c-a013-11d3-9c8b-00e098055175"))

Igscript : IDispatch

{

//

// Wrapper methods for error-handling

//

HRESULT MakeFile (

_bstr_t inputfile,

_bstr_t outputfile,

_bstr_t devicename );

//

// Raw methods provided by interface

//

virtual HRESULT __stdcall raw_MakeFile (

/*[in]*/ BSTR inputfile,

/*[in]*/ BSTR outputfile,

/*[in]*/ BSTR devicename ) = 0;

};

//

// Wrapper method implementations

//

#include "e:\sureshshanmugam\psudocodes\test2_vc\debug\comgs.tli"

} // namespace COMGSLib

#pragma pack(pop)

prasad_som29-Dec-06 0:28

Re: How can i call COM DLL in vc++ 2005? [modified]

29-Dec-06 0:28

surezu wrote:
I followed correctly through ur sending article

No , you haven't.
You are mixing simple dll with COM dll.
In case of COM dll, there would interface(s) present. Which you need to use. This interface in your case is Igscript .
You haven't noticed how interface need to be used from C++ client. Look in to CMfcclientDlg::OnOk.
You need to use CoCreateInstance for this purpose.
Refer CMfcclientDlg::OnOk. from article and post back, if got any issue.

Prasad
Notifier using ATL | Operator new[],delete[][^]

$uresh $hanmugam29-Dec-06 4:22

29-Dec-06 4:22

Hi Prasad,

I got result and i knew some basic concepts about COM based DLL.
Thank you very much.

-- modified at 7:30 Tuesday 2nd January, 2007

Amateur

Shouvik Das27-Dec-06 20:33

Shouvik Das

27-Dec-06 20:33

hi there,

To be using COM in my final year proj. Can anybody point me out very good reference - Online/literature. it'd of immense help as i need to learn it as a crash course Blush | :O

.

plz help

Shouvik

prasad_som28-Dec-06 1:56

28-Dec-06 1:56

Refer COM[^] section on this site.

Prasad
Notifier using ATL | Operator new[],delete[][^]

Shouvik Das28-Dec-06 2:02

Shouvik Das

28-Dec-06 2:02

Thanks Prasad,

Till now all my posts are replied by u first Smile | :)

thanks a lot

Shouvik

prasad_som28-Dec-06 2:16

28-Dec-06 2:16

Most welcome ! Smile | :)

Hope , it helps you in some way.

Majority of CP'ians are on vacation, otherwise, you will get lots of replies.

Prasad
Notifier using ATL | Operator new[],delete[][^]

Shouvik Das28-Dec-06 2:31

Shouvik Das

28-Dec-06 2:31

I also need to get some hands on Text parsing like Natural Language processing. Can u help me out.
I know this is out of thread ques. Plz bear with me.

please if u can... Smile | :)

Shouvik

prasad_som28-Dec-06 2:48

How can i use MODI in Vc++?

28-Dec-06 2:48

shouvik.d wrote:
Natural Language processing

Frankly, I'vent seen much of it, too. Better you ask this to larger audience, may be somebody has good knowledge of it.
Try General discussions/ lounge on this site, for this question.

Prasad
Notifier using ATL | Operator new[],delete[][^]

TLBIMP.exe and COM

mgmail27-Dec-06 8:34

mgmail

27-Dec-06 8:34

I have a webapp which uses a COM dll by way of a wrapper.

the last time i made changes to this object i was able to recreate the wrapper and it worked successfully.

now i am again modifying the the code of the object (nothing special, just added an order clause to a sql statement) however this time when i generate the wrapper, the webapp fails with the follwing runtime error

Could not load type StmtGeneratorNET.StatementGeneratorClass from assembly StmtGeneratorNet

any ideas what the problem is here ?

Re: TLBIMP.exe and COM

mgmail27-Dec-06 9:39

mgmail

27-Dec-06 9:39

Here is some additional information

when running TlbImp.exe i get the following warning, the wrapper dll is generated as is VBA.dll

TlbImp warning: Type library importer has encountered an interface not derived from IUnknown: _HiddenInterface.

however the webapp still cannot access the type required.

$uresh $hanmugam26-Dec-06 19:27