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I am VC Developer and I am working on a COM wrapper for a DLL that we have.... I need to be able to pass DWORD (unsigned long) and WORD (unsigned short) values into this COM DLL.
THe Problem is that the DLL has to be able to be used from VB...When I compile my COM DLL and try and use the functions in VB it reports that VB does not support the automation type...
Any help you could give me would be greatly appreciated..
Joe Wiemann
Software Engineer
Daktronics Inc.
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Can't you use the Variant type?
"Want to know what makes me mad? Everything!" The Ranting Swede.
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I agree completely, I never use them, but then I don't do COM. I just thought that the entire purpose of the variant type was for compatibility between the C world and the VB world.
"Want to know what makes me mad? Everything!" The Ranting Swede.
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There are no unsigned types in VB. Can you convert them to their signed counterparts before you pass them?
I vote pro drink ![Beer | [beer]](https://codeproject.global.ssl.fastly.net/script/Forums/Images/beer.gif)
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How to find the users that logged on one domain?
Which funntion or api to use?
sandos
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Cannot add files to project.
It raise an exception and close.
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Using CoCreateInstance(...) will create an instance, but what I need is to link to an already existing IE window. Is this possible? How can I do this?
Thx!
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I have to read and write on the contents tab(which appears when u rigth click on any word file and select the properties).i am able to read and write rest all the tabs like (General,Summary,Statstic and custom) but not on contents. I am using IPropertySetStorage. the code i am using is given below please suggest some solution.........its urgent
the code i am using is described below
#define UNICODE
#define _UNICODE
#define WIN32_LEAN_AND_MEAN
#define UNICODE
#define _UNICODE
#include
#include
#include
#include
// Implicitly link ole32.dll
#pragma comment( lib, "ole32.lib" )
#include
// From uuidgen.exe:
//b725f130-47ef-101a-a5f1-02608c9eebac
//79c1e210-9ad8-11d5-ae31-000102572d6d
/*const FMTID fmtid = { /* d170df2e-1117-11d2-aa01-00805ffe11b8
0xd170df2e,
0x1117,
0x11d2,
{0xaa, 0x01, 0x00, 0x80, 0x5f, 0xfe, 0x11, 0xb8}
};*/
const FMTID fmtid = { /* d170df2e-1117-11d2-aa01-00805ffe11b8 */
0xb725f130,
0x47ef,
0x101a,
{0xa5, 0xf1, 0x02, 0x60, 0x8c, 0x9e, 0xeb, 0xac}
};
EXTERN_C void wmain()
{
HRESULT hr = S_OK;
IPropertySetStorage *pPropSetStg=NULL,*pPropSetStg1=NULL;
IPropertyStorage *pPropStg = NULL,*pPropStg1 = NULL;
WCHAR *pwszError = L"";
LPSTORAGE pFileStorage = NULL;
PROPVARIANT propvarWrite, propvarWrite1;
PROPSPEC propspec;
try
{
// Create a file and a property set within it.
hr = StgCreateDocfile( L"d:\\temp\\WriteRead.doc",
STGM_CREATE|STGM_SHARE_EXCLUSIVE|STGM_READWRITE,
0,
&pFileStorage);
if( FAILED(hr) ) return ;//throw L"Failed StgCreateStorageEx";
/*//#CHNG rajeev
LPSTORAGE pStorage;
hr = pFileStorage->CreateStorage( L"\005MyStorage",
STGM_CREATE|STGM_SHARE_EXCLUSIVE|STGM_READWRITE,
0,
0,
&pStorage);
LPSTREAM pStream1;
hr = pFileStorage->CreateStream( L"\005MyStream",
STGM_CREATE|STGM_SHARE_EXCLUSIVE|STGM_READWRITE,
0,
0,
&pStream1);
if ( FAILED(hr)) return;
CComBSTR ab("\005abcd");
unsigned long count;
pStream1->Write(ab,ab.Length(),&count);
*/
//
//#CHNG rajeev*/
//FMTID_DocSummaryInformation //for the summary coc
//FMTID_UserDefinedProperties
pFileStorage->QueryInterface(IID_IPropertySetStorage,(void **) &pPropSetStg1);
hr = pPropSetStg1->Create( FMTID_SummaryInformation, NULL, PROPSETFLAG_DEFAULT ,
STGM_CREATE|STGM_READWRITE|STGM_SHARE_EXCLUSIVE,
&pPropStg1 );
propspec.ulKind = PRSPEC_PROPID;
propspec.propid = 0x000000002;
PropVariantInit( &propvarWrite1 );
propvarWrite.vt = VT_LPWSTR;
propvarWrite.pwszVal = L"abc";
hr = pPropStg1->WriteMultiple( 1, &propspec, &propvarWrite, 0x00000000D);
if( FAILED(hr) ) throw L"Failed IPropertyStorage::WriteMultiple";
//////////code added by pankaj/////////////////
pFileStorage->QueryInterface(IID_IPropertySetStorage,(void **) &pPropSetStg);
hr = pPropSetStg->Create( FMTID_DocSummaryInformation, NULL, PROPSETFLAG_DEFAULT ,
STGM_CREATE|STGM_READWRITE|STGM_SHARE_EXCLUSIVE,
&pPropStg );
if( FAILED(hr) ) throw L"Failed IPropertySetStorage::Create";
// Write a Unicode string property to the property set
// propspec.ulKind = PRSPEC_LPWSTR;
// propspec.lpwstr = L"Property Name";
propspec.ulKind = PRSPEC_PROPID;
propspec.propid = 0x00000000C;
///
PropVariantInit( &propvarWrite1 );
propvarWrite1.vt = VT_LPWSTR;
propvarWrite1.pwszVal = L"Tittle";
propvarWrite.vt = VT_VARIANT | VT_VECTOR;
propvarWrite.capropvar.cElems = 1;
propvarWrite.capropvar.pElems = &propvarWrite1;
hr = pPropStg->WriteMultiple( 1, &propspec, &propvarWrite, 0x00000000D);
if( FAILED(hr) ) throw L"Failed IPropertyStorage::WriteMultiple";
LPSTR abc="Tittle";
//propspec.lpwstr = L"Contents";
propspec.propid = 0x00000000D;
propvarWrite.vt = VT_VECTOR | (VT_LPWSTR);
propvarWrite.calpstr.cElems = 1;
propvarWrite.calpstr.pElems = &abc;
hr = pPropStg->WriteMultiple( 1, &propspec, &propvarWrite, 0x000000002);
if( FAILED(hr) ) throw L"Failed IPropertyStorage::WriteMultiple";
/*propspec.propid = 0x00000000D;
propvarWrite.vt = VT_STORAGE;
propvarWrite.pStorage = pStorage;
hr = pPropStg->WriteMultiple( 1, &propspec, &propvarWrite, 0x000000002);
if( FAILED(hr) ) throw L"Failed IPropertyStorage::WriteMultiple";*/
propspec.ulKind = PRSPEC_PROPID;
propspec.propid = 0x000000003;
PropVariantInit( &propvarWrite );
propvarWrite.vt = VT_LPWSTR;
propvarWrite.pwszVal = L"RajeevSoft Inc. Punjab";
hr = pPropStg->WriteMultiple( 1, &propspec, &propvarWrite, 0x000000004);
if( FAILED(hr) ) throw L"Failed IPropertyStorage::WriteMultiple";
propspec.ulKind = PRSPEC_PROPID;
propspec.propid = 0x00000000A;
PropVariantInit( &propvarWrite );
propvarWrite.vt = VT_I4;
propvarWrite.iVal = 1234;
hr = pPropStg->WriteMultiple( 1, &propspec, &propvarWrite, 0x000000005);
if( FAILED(hr) ) throw L"Failed IPropertyStorage::WriteMultiple";
PROPID propidDictionary=PID_DICTIONARY;
WCHAR *pwszFriendlyName = L"Write/Read Properties Sample Property Set";
hr = pPropStg->WritePropertyNames( 1, &propidDictionary, &pwszFriendlyName );
if( FAILED(hr) ) throw L"Failed IPropertyStorage::WritePropertyNames";
pPropStg->Release(); pPropStg = NULL;
pPropSetStg->Release(); pPropSetStg = NULL;
pPropStg1->Release(); pPropStg1 = NULL;
pPropSetStg1->Release(); pPropSetStg1 = NULL;
pFileStorage->Release();pFileStorage = NULL;
// pStream1->Release();
}
catch( const WCHAR *pwszError )
{
wprintf( L"Error: %s (hr=%08x)\n", pwszError, hr );
}
if( pPropStg ) pPropStg->Release();
if( pPropSetStg ) pPropSetStg->Release();
if( pPropStg1 ) pPropStg1->Release();
if( pPropSetStg1 ) pPropSetStg1->Release();
}
Pankaj Mongia
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I installed .Net,and I found the component writed with VB was correct while debug step by step,then I make the dll.But it does not work correct.(In one method of this component ,I called one function of another dll just for unzip files.)
If this is caused by .net?
sandos
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Dear all,
Pls look at this problem.
HRESULT has many pre-defined values, each associated with an error-message,
which can be extracted using _com_error class like this :
HRESULT hr = some-method();
if(FAILED(hr)
{
_com_error ce(hr);
cout << ce.ErrorMessage();
}
Similar way how I can define a new value of HRESULT type, and map it to
app-specific error messages, which I can extract using above method.
Any timely help is apperiaciated.
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you need to support ISupportErrorInfo in your com object (usually selected through the wizard when creating the COM project)
then call Error from your Method.
return Error(_bstr_t("Bespoke Error").copy(), IID_IObj);
This will give you a bespoke error description.
It has been suggested that you should not generate your own HRESULT, even though you can do it as M$ may use the value you generated in the future.
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Hi,
I am embedding MSWord In my application, using OLE automation.
But when I goto save i get the saveas method is not available as the
document is been editted in another application.
Code As Follows, from the CanCloseFrame
CEmbedWordCntrItem* ViewObj;
ViewObj = ((CEmbedWordView*)pFrame->GetActiveView())
- >m_pSelection;
LPDISPATCH lpDispatch = (ViewObj->GetIDispatch());
_Document doc;
doc.AttachDispatch(lpDispatch);
COleVariant covFalse((short)FALSE);
COleVariant vtOptional((long)DISP_E_PARAMNOTFOUND,VT_ERROR);
doc.SaveAs(COleVariant("C:\\DataDoc.doc",VT_BSTR), vtOptional.........)
Cheers
Richard
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I'm trying to create a COM obj. that has events. Is that possible? and if so, how? (you can be pretty general, i'll be able to figure most of it out)
~
SHABBA!!
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Yeah Master, you must implement IConnectionPoints.
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Hi,
I've got an active x control packaged up and signed in a .cab file
the only problem left is marking it safe for scripting and inialising. I have some code that has come with the internet SDK files called CATHELP.h ,.CPP and how to call them in the DLLRegisterServer function, but they don't have any effect!
I can use the regediter and manually set the implemented catigories, and it works fine then , but this isn't a good way to go.
Does anyone have any experience with the CATHELP.h,.CPP files or anyother way to mark a control as safe?
thanks.
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In a ATL project I have a coclass CMonitorClt with an outgoing interface called _IMonitorCltEvents with a method called DataReceived([in] BSTR Key, [in] BSTR Data).
The coclass creates a thread (receiver-thread) that is responsible for receiving something on a socket and fireing an event on the outgoing interface.
The coclass have a ATL-generated Fire_DataReceived(BSTR Key, BSTR Data) method that can be called to fire an event in the client. To make Fire_DataReceived() available to the receiver-thread I have passed a reference to the coclass in CreateThread(). When I call the Fire_DataReceived function from the receiver-thread the client (VB6) crashes - Dohh.
I think I know what the problem is - the outgoing interfacepointer needs to be marshalled between the main-thread and the receiver-thread with CoMarshalInterThreadInterfaceInStream() and CoGetInterfaceAndReleaseStream() in order to call a method on the interface. But can this be done? The interfacepointers are held and managed by the coclass (derived from IConnectionPointImpl) and the receiver-thread knows nothing about these interfacepointers and when they should be marshalled.
How can I use ConnectionPoint and fire an event on a connectionpoint from a thread that is not a main-thread?
Søren Randrup
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The most simple way to do this is use MTA (Multiple Thread Apartment) in your COM Object.
Also make sure that you are using ::CoInitializeEx(...) and ::CoUnitialize() in each thread that you have created.
This loads the OLE libarary for each thread, this is required if you are using COM Objects in the Threads
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What's wrong with the convertion?:
CComVariant varStrRet(ostrBuffer.str().c_str());
ostrBuffer is ostringstream. Everithing works fine but if I load more then aprox. 500Kb into ostrBuffer the the convertion result in access violetion. Enyone knows why?
Thanks a lot for any help
Peter
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I'm trying to learn Visual C++ but I've the problem that everytime I get the typical window-crash-nobody-knows-why and I restore my computer, the project browser doesn't display anything and I get the message above.
Could somebody tell me how to restore the classview information file?
Thanks.
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For Classview
Before opening Visual Studio, delete the myProject.ncb file
Where myProject is the name of your project.
For ClassWizard
Delete the myProject.clw file
Both these files will be rebuilt for you.
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Hi
I queried for a interface pointer in a constructor and want to use it across
several functions.I need that pointer in many functions but dont know where to release it and how to do it?Can I release it in destructor of the class in which i queried and using?
Please help me
Thanks
Pathi
bhikshapathi_g@semanticspace.com
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From your general description I would say releasing the interface pointer in the destructor would be sufficient.
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I wrote an ATL NT service? i want to use CPtrlist class,but the project doesn't support MFC?How can i
add such support?
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Why burdon yourself, and your code, with adding MFC? Why not just use and STL container such as a list, deque, etc.?
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