hello som you have helped me a lot to solve my problem....i just mail you here to say thank you very much for your support and help...for coding and corresction... And yes one more thing this error is just no more when i have used the try,catch block.....and now my project is working fine.... Haappy New Year Regards Priyanka

error C2872: '_DBAccess' : ambiguous symbol

thanks i have used the same link to proceed with....but still facng the problem....after #import dll when i use namespace it report the error....why...

can you pls point me wher i am making big mistake....pls when i use this code it also give error error C2787: '_DBAccess' : no GUID has been associated with this object hresult=CoCreateInstance(clsid,NULL,CLSCTX_INPROC_SERVER,__uuidof(_DBAccess),(LPVOID *) &t); But i have seen in .tlh file clsid is attach with this ....

i have change my code also to laod dll.....now what to do....you have hepled me before also...thank you

when it comes to setquotetodb function it gives error...i just dont know what to do,i have given my 100%....pls help me

see i have chkge the code still i am not able to locate my function.....i have tried all my best...pls help me...still it return null...and for function call setquotetodb is....unhandled exeption in apiocx access violation. code here

HRESULT hresult;
CLSID clsid;

CoInitialize(NULL);
hresult=CLSIDFromProgID(OLESTR("WartzODLCOM.DBAccess"),&clsid);
\_DBAccess \*t;
hresult=CoCreateInstance(clsid,NULL,CLSCTX\_INPROC\_SERVER,\_\_uuidof(IDispatch ),(LPVOID \*) &t);

if(FAILED(hresult))
{
AfxMessageBox("Creation Failed");
return;
}

else
{
MessageBox("success");
}

SessID=SessionId;
CurrentRequestId=RequestId;

marketno.Format("%d",MarketNo);
bid\_d.Format("%c",BidDirection);
ask\_d.Format("%c",AskDirection);
marketstate.Format("%d",MarketState);

   m\_MainEdit= SessionId + "\\t" + RequestId +"\\t"+ marketno ; 
m\_MainEdit= Market + Bid  + bid\_d +  Ask +ask\_d High ;
m\_MainEdit=m\_MainEdit + Low  + marketstate   + Timestamp ;

UpdateData(FALSE);
iLineCount=m\_EditCtrl.GetLineCount();
m\_EditCtrl.LineScroll(iLineCount);

if(hresult != NULL)
{
MessageBox("not null");
USES_CONVERSION;
BSTR bsTimeStamp = A2BSTR(Timestamp);
BSTR bsMarket = A2BSTR(Market);
BSTR bsBid = A2BSTR(Bid);
BSTR bsAsk = A2BSTR(Ask);

// SetQuote(&bsTimeStamp,&MarketNo,&bsMarket,&bsAsk,&bsBid,&MarketState);
t->setQuoteToDB(&bsTimeStamp,&MarketNo,&bsMarket,&bsAsk,&bsBid,&MarketState);
SysFreeString(bsTimeStamp);
SysFreeString(bsMarket);
SysFreeString(bsBid);
SysFreeString(bsAsk);
}
else
{
MessageBox("null");
}
// FreeLibrary( hInstance );

CoUninitialize();

return;
}

while using this code....unhandled exeption in a.exe(apiocx):0xc0000005 Access Violation any solution

HRESULT hresult;
CLSID clsid;

CoInitialize(NULL);
hresult=CLSIDFromProgID(OLESTR("WartzODLCOM.DBAccess"),&clsid);
    \_DBAccess \*t;
hresult=CoCreateInstance(clsid,NULL,CLSCTX\_INPROC\_SERVER,\_\_uuidof(IDispatch ),(LPVOID \*) &t);

if(FAILED(hresult))
{
AfxMessageBox("Creation Failed");
return;
}

else
{
MessageBox("success");
}

SessID=SessionId;
CurrentRequestId=RequestId;

marketno.Format("%d",MarketNo);
bid\_d.Format("%c",BidDirection);
ask\_d.Format("%c",AskDirection);
marketstate.Format("%d",MarketState);

    m\_MainEdit= SessionId  + RequestId + marketno ; 
m\_MainEdit=Market +  Bid + bid\_d + Ask + ask\_d + High 
m\_MainEdit= Low  + marketstate  + Timestamp ;
UpdateData(FALSE);
iLineCount=m\_EditCtrl.GetLineCount();
m\_EditCtrl.LineScroll(iLineCount);

if(hresult != NULL)
{
USES_CONVERSION;
BSTR bsTimeStamp = A2BSTR(Timestamp);
BSTR bsMarket = A2BSTR(Market);
BSTR bsBid = A2BSTR(Bid);
BSTR bsAsk = A2BSTR(Ask);

t->setQuoteToDB(&bsTimeStamp,&MarketNo,&bsMarket,&bsAsk,&bsBid,&MarketState);
SysFreeString(bsTimeStamp);
SysFreeString(bsMarket);
SysFreeString(bsBid);
SysFreeString(bsAsk);
}
else
{
MessageBox("null");
}
FreeLibrary( hInstance );

CoUninitialize();

return;
}

you can find lot of project here hoe to load vc++ dll....see this link http://www.codeproject.com/dll/[^]

I am also strrugling with same problem....you can have look at this site it may be helpful to you http://www.codeproject.com/dll/vbactivexwithvc.asp[^]

when using this got error no guid is attach,how to solve this error C2787: '_DBAccess' : no GUID has been associated with this object hresult=CoCreateInstance(clsid,NULL,CLSCTX_INPROC_SERVER,__uuidof(_DBAccess),(LPVOID *) &t);

No i am still stuck with same problem...do you have any clear idea how to call com dll function....i think my problem is that only....pls if you can help me....

can anybody help me to give simple steps to call "com dll function"....thank you:)

when i use dependency walker to check my dll and its function....and when i open my dll there are two window top and bottom...with some tab Ordinal Hint Function Entry Point In this tab i am not able to see nay of my dll function what does this mean

how to use dependency walker to check that everything is getting linked properly...for dll

there are lots of project online better try to search...all the best:laugh:

do you have any link,i have never used this function before

no

yes i think ,see my code....

HINSTANCE hInstance ;

hInstance = AfxLoadLibrary("C:\\ActiveXdll\\WartzODLCOM.dll");
if(hInstance != NULL)
{
//dont go further
MessageBox("load dll");
}
else
{
MessageBox("enable to load dll");
}

//"GetProcAddress" get the address of the functions
SetQuote = (Set_Quote_DB)GetProcAddress(hInstance,"setQuoteToDB");
if(SetQuote != NULL)
{

   MessageBox("set quote is not null");
 	
}	
else
{
	MessageBox("set quote is null");
}

i am trying to get address of dll function but not able to do that,any idea how to solve it..... it always return null....

SetQuote = (Set_Quote_DB)GetProcAddress(hInstance,"setQuoteToDB");
if(SetQuote != NULL)
{

   MessageBox("set quote is not null");
 	
}	
else
{
	MessageBox("set quote is null");
}