Get varient array from VC++ dll to vb.net application - vb.net

Question

I have to get the Features array in vb.net application. How this can be done. This is a function in VC++ .
STDMETHODIMP CclsLicense::FeatureList(VARIANT* Features,BSTR HostName, VARIANT_BOOL *ret){
USES_CONVERSION;
int status = 0;
int iCount = 0;
int nLicenseFeatures = 0;
char **featureList = NULL; // List of features
// Safe Array
SAFEARRAYBOUND bound[1];
SAFEARRAY *safeArray = NULL; // A Safe array for VB
CComVariant *pBstr = NULL; // Array of BSTR Value
// Initialize the return value
*ret = VARIANT_FALSE;
nLicenseFeatures = 0;
featureList = new char*[MAX_FEATURES];
for (i=0;i<4;i++)
{
featureList[nLicenseFeatures]=array[i];
nLicenseFeatures++;
}
// Array starts at 0 and has the number of features as elements
bound[0].lLbound = 0;
bound[0].cElements = nLicenseFeatures;
// Initialize Array
if((safeArray = ::SafeArrayCreate( VT_VARIANT, 1, bound)) == NULL)
return E_FAIL;
::VariantClear(Features);
Features->vt = VT_VARIANT | VT_ARRAY;
Features->parray = safeArray;
//use direct access to data
if(FAILED(hr = ::SafeArrayAccessData(safeArray, (void HUGEP**)&pBstr)) || pBstr == NULL)
return hr;
iCount = 0;
while( featureList[iCount] != NULL )
{
// Add to Array
if(pBstr[iCount].bstrVal != NULL)
{
::SysFreeString(pBstr[iCount].bstrVal);
pBstr[iCount].bstrVal = NULL;
}
if(featureList[iCount] == NULL)
pBstr[iCount].bstrVal = ::SysAllocString(OLESTR("")); //imposible
else
pBstr[iCount].bstrVal = ::SysAllocString(T2OLE(featureList[iCount]));
pBstr[iCount].vt = VT_BSTR;
// Increment counter
iCount++;
}
// Release Array
::SafeArrayUnaccessData(safeArray);
*ret = VARIANT_TRUE;
return S_OK;
}
Vb.Net function to get the list of features
Public Shared Function FeatureList(ByVal strLicensePath As String)
Dim features(10) As String
Try
m_objUTSLicense = CreateObject("dll name")
Call m_objUTSLicense.FeatureList(features, "192.168.1.3")
Catch ex As Exception
End Try
Dim i As Integer
Dim size As Integer = features.Length
For i = 0 To size - 1
MessageBox.Show(features(i))
Next
End Function
When i am trying this code, getting the error "Attempted to read or write protected memory. This is often an indication that other memory is corrupt"

Answer 1

I can't test this without your whole project, but you might try declaring a member variable (rather than a local) so that you can apply the necessary marshalling attribute. Something like:
Imports System.Runtime.InteropServices
<MarshalAs(UnmanagedType.SafeArray, safearraysubtype:=VarEnum.VT_BSTR)>
Private features As System.Array