return a safearray as a variant from a COM objects

[abramowi]

Hi!

I'm trying to retun a safe array as a variant in a COM object. This is what I do:

COMObject::GetArray(VARIANT* arr)
{
CComSafeArray<BSTR> safeArray;
safeArray.add(&quot;Hello&quot;

CComVariant return(safeArray);
ret.Detach(groups);
}

However, when I try to get the array from VB Script using the following lines:

Dim Arr
Arr = comobj.GetArray

I get the following error:

Invalid access to memory location

has ANYONE got any idea why??? It would be really nice to solve this prob before Monday.

Thanks in advance /dave

 

[onlyshiza]

Hi Dave,

For the safearrays you should use
- Use SafeArrayCreate() to create the array
and
- Use SafeArrayAccessData() to gain access to the array’s data elements

otherwise you most likely run into memory problems as you did.
if you have access to MSDN get some more info on these.
Hope this helps

Cheers,
onlyshiza

 

[abramowi]

Thank you for your quick reply. Hmmm... I tried changing the code to:

COMObject::GetArray(VARIANT* arr)
{
CComSafeArray<BSTR> * safeArray = new CComSafeArray<BSTR>(1); //parameter is size of array
safeArray.add(&quot;Hello&quot;

CComVariant return(*safeArray);
ret.Detach(groups);
}

And I still get the same exception.

 

[onlyshiza]

Hey,

sorry man, I overlooked that you are using CCOMSafeArray. This is new to ATL 7.0 and I am not very familiar with it, there are no wrapper classes in ATL 3 for safearrays. However might find some hints on this link:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vclib/html/vclrfccomsafearray.asp

seems you have to set the bounds first. sorry couldn't help!

good luck,