From: Katiyar, Subodh (Path) (skatiyarAFSINDIA.COM)
Date: Tue Feb 17 2004 - 23:42:21 CST

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kim
i can't help laughing at my stupid pArray->cDims=1 mistake
 
the sample code works fine when it is called from vb client
when i call it from asp client with an array of (2,4) with following values

vin(0,0)="a"
vin(0,1)="b"
vin(0,2)="c"
.....
and so on i fill till h
when i try to call this asp page
i get -> a e b f c g Vame from dbl dim
now what could be misbehaving in here?and one more thing if i pass it a single dim array from asp it prints fine.

regards

-----Original Message-----
From: Kim Gräsman [mailto:kim.grasmanLABS2.COM]
Sent: Wednesday, February 18, 2004 12:34 Subah
To: DCOMDISCUSS.MICROSOFT.COM
Subject: Re: Passing variant arrays from asp to atl component doesn't
work

Hi Subodh,

> if (!(vin->vt & VT_ARRAY) || !(vin->vt & VT_BSTR))
> return 1 ;

This implies that you're looking for a SAFEARRAY of BSTR... VBScript only
handles SAFEARRAY of VARIANT, so I'm surprised that it works at all.

> if (pArray->cDims=1)
> //problem here cDims is always 1 either i pass single dim or dbl dim

No surprise - you're assigning one to pArray->cDims.

All in all, here are a couple of tips:

- Be as explicit with types as you can, i.e. prefer BSTR to VARIANT (what is
spmname? verr?)
- Always dereference incoming VARIANTs, either with VariantCopyInd
(expensive), or some manual inspection (cheap, but cumbersome)
- Avoid [out] only with scripting languages. VBScript can't figure out how
to deallocate complex types (BSTR, objects, arrays, etc) with [out], only
with [out, retval].

See below for a working version.

Hope that helps,
Kim

// ---
STDMETHODIMP CInvoke::Go(VARIANT *spmname, VARIANT *vin, VARIANT *vout,
VARIANT *verr)
{
        HRESULT hr;

        CComBSTR newBstr;

        // Dereference variant
        CComVariant vaInArray;
        hr = VariantCopyInd(&vaInArray, vin);
        if(FAILED(hr)) return hr;

        // Validate
        if(vaInArray.vt != (VT_ARRAY | VT_VARIANT))
        {
                return E_INVALIDARG;
        }

        // Access raw variant data
        VARIANT* bvararrayddim = NULL;
        SAFEARRAY* psa = vaInArray.parray;
        ::SafeArrayAccessData (psa, (void**)&bvararrayddim);

        // Traverse variant buffer, and build BSTR
        long c = 0;
        for(int j = 0; j < psa->cDims; j++)
        {
                for(unsigned int i = 0; i < psa->rgsabound[j].cElements;
i++, c++)
                {
                        if(bvararrayddim[c].vt == VT_BSTR)
                        {
                                newBstr += bvararrayddim[c].bstrVal;
                        }
                }
        }

        // Append some value and return
        newBstr += "Vame from dbl dim";
        verr->vt = VT_BSTR;
        verr->bstrVal = newBstr.Detach();

        return S_OK;
}

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