COM

void f(IMediaEvent * p)
{
    if( p != NULL )
    {
        IDeliveredEvent * l_p(NULL);
        HRESULT const l_hr(p->QueryInterface(
            IID_IDeliveredEvent, 
            reinterpret_cast<void**>(&l_p)));

        if( SUCCEEDED(l_hr) )
        {
            // use l_p
            l_p->Release();
        }
    }
}

LPDISPATCH   lpDisp = m_shControl.GetActiveDocument();<br />
DISPID dispid;<br />
OLECHAR FAR* szFunction;<br />
szFunction = OLESTR("Protect");<br />
//DISPPARAMS dispparamsNoArgs = {NULL, NULL, 0, 0};<br />
// parameter structure<br />
DISPPARAMS dispparams;<br />
// one-element array of parameter names<br />
DISPID mydispid[1] = { DISP_PROPERTYPUT };<br />
// one-element array of parameters<br />
VARIANTARG vararg[1];<br />
dispparams.rgvarg = vararg; // 1-element array<br />
VariantInit(&dispparams.rgvarg[0]);<br />
dispparams.rgvarg[0].vt = VT_I4;   // 32-bit integerwdAllowOnlyRevisions<br />
dispparams.rgvarg[0].iVal =2 ; <br />
dispparams.rgdispidNamedArgs = mydispid; // name array<br />
dispparams.cArgs = 1;      // total args<br />
dispparams.cNamedArgs =1;   // named args<br />
<br />
HRESULT hr = lpDisp->GetIDsOfNames (IID_NULL, &szFunction, 1, <br />
                             LOCALE_USER_DEFAULT, &dispid);<br />
<br />
hr = lpDisp->Invoke (dispid, IID_NULL, LOCALE_USER_DEFAULT,<br />
                       DISPATCH_METHOD, &dispparams, NULL, NULL, <br />
                       NULL);