Re: VB Activex dll in VC++ with array parameter

From:
Andrea Visinoni <andrea.visinoni@gmail.com>
Newsgroups:
microsoft.public.vc.mfc
Date:
Fri, 4 Mar 2011 03:13:15 -0800 (PST)
Message-ID:
<a7da0a79-4d13-4e74-8fdc-075b8905c954@y14g2000vbb.googlegroups.com>
this seems to work correctly (unluckily i still don't have the device
to properly try)

CoInitialize(NULL);

SAFEARRAY *psaOut = SafeArrayCreateVector(VT_BSTR, 0, 32);

try
{
        HRESULT res;

        Qpod_DLL::_cQPodPtr ptr;

        res = ptr.CreateInstance("Qpod_DLL.cQPod");

        if (res == S_OK)
            long ret = ptr->FindQpods(&psaOut);
}
catch(_com_error &e)
{
        TRACE1("Err: %s\n", e.Description());
}

CoUninitialize();

i only have this exception:
First-chance exception in activex.exe (KERNEL32.DLL): 0xC000008F:
Float Inexact Result.

On 4 Mar, 10:46, Andrea Visinoni <andrea.visin...@gmail.com> wrote:

I think it's more or less like the second example in:http://support.micro=

soft.com/kb/194873/en-us

but it's still not clear to me what are these:

yourserver::IYourObjectPtr
p(yourClassWizardGeneratedObject.m_lpDispatch);

On 4 Mar, 10:29, Goran <goran.pu...@gmail.com> wrote:

On Mar 4, 9:18 am, Andrea Visinoni <andrea.visin...@gmail.com> wrote:

The problem is that this is DLL come from a device and the only thing
i have is a useless pdf with
this prototype:
FindQpods (By Ref sSNArray(0 to 32)) [=lRtnVal]

and this info from a IDL file generated by OLE viewer (analyzing the
DLL)

[id(0x60030002)]
        HRESULT FindQpods(
                        [in, out] SAFEARRAY(B=

STR)* SNArray,

                        [out, retval] long* )=

;

the automatic procedure of VC++ 6.0 creating an IDispatch class to
interface to the DLL, failed on all the methods having arrays as
parameter.


You might try using #import, then call the method directly. E.g.

#import "yourserver.tlb" // or dll or exe

yourserver::IYourObjectPtr
p(yourClassWizardGeneratedObject.m_lpDispatch);
SAFEARRAY a = PrepareSafearrayWithStringsInIt();// (educated guess on
what FindQPods need)
long count;
p->FindQPods(&a, &count);

Goran.

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