How to pass byte array from c# to MFC ActiveX

Question

I'm writing simple c# app.

It's really simple. c# app calls activeX function with byte array as parameter, and then, activeX receives byte array and presents it.

I'm asking, Which data type I have to use in MFC ActiveX? Variant? Variant*?

Any help will be appreciated. Thanks.

Answer 1

A VARIANT of type VT_ARRAY|VT_UI1 . Code sample:

char original_buffer[1024];
SAFEARRAY FAR* psa;
SAFEARRAYBOUND rgsabound[1];

// fill original_buffer here

rgsabound[0].lLbound = 0;
rgsabound[0].cElements = 1024;
psa = SafeArrayCreate(VT_UI1, 1, rgsabound);
void* p=(char*)psa->pvData;

if (psa)
{                   
    VARIANT variant_buffer;
    VariantInit(&variant_buffer); 
    variant_buffer.vt = VT_ARRAY|VT_UI1;
    variant_buffer.parray = psa;

    void* p = (char*)psa->pvData; 
    memcpy(p, (void*)original_buffer, 1024); 

    // do someting with the array here

    SafeArrayDestroy(psa);
}