VB Forum / COM / December 2005

I'm trying to figure out how events are generated in VC++ ATL and then
received in VB. I already have a working example to which I want to add an
event function. In the IDL file I have added the function name to the
dispinterface as follows:

[id(10)] void Hover(BSTR someString);

Then, when I want to fire the event I call

obj->Fire_Hover(someString);

and the Fire_Hover function:

VOID Fire_Hover(BSTR someString)
{
T* pT = static_cast<T*>(this);
int nConnectionIndex;
CComVariant* pvars = new CComVariant[1];
int nConnections = m_vec.GetSize();

for (nConnectionIndex = 0; nConnectionIndex < nConnections;
nConnectionIndex++)
{
pT->Lock();
CComPtr<IUnknown> sp = m_vec.GetAt(nConnectionIndex);
pT->Unlock();
IDispatch* pDispatch = reinterpret_cast<IDispatch*>(sp.p);
if (pDispatch != NULL)
{
pvars[0] = someString;
DISPPARAMS disp = { pvars, NULL, 1, 0 };
pDispatch->Invoke(0x10, IID_NULL, LOCALE_USER_DEFAULT, DISPATCH_METHOD,
&disp, NULL, NULL, NULL);
}
}
delete[] pvars;
}

Now, probably there's something I haven't done since the VB function

myObj_Hover(ByVal someString As String)

is not called. The Hover event appears for the class in the object
browser of VB. What have I forgotten?