On Friday, 28 April 2017 at 09:25:31 UTC, John Chapman wrote:
On Thursday, 27 April 2017 at 20:20:23 UTC, Nierjerson wrote:
QueryInterface is COM's version of opCast. It asks if you
support the interface represented by an IID (riid). If you
don't, then you return E_NOINTERFACE. If you do, then you point
the result (pvObject) to yourself and return S_OK. Here's a
basic implementation:
extern(Windows)
HRESULT QueryInterface(IID* riid, void** pvObject) {
if (pvObject is null) return E_POINTER;
*pvObject = null;
if (*riid == IID_IUnknown) *pvObject =
cast(void*)cast(IUnknown)this;
else if (*riid == IID_IDispatch) *pvObject =
cast(void*)cast(IDispatch)this;
// and so on for all interfaces we support
if (*pvObject is null) return E_NOINTERFACE;
(cast(IUnknown)this).AddRef();
return S_OK;
}
Your code works. I had something similar but I think I was
returning a null pointer on IID_Unknown or something similar. I
now get a different error but it is a COM error rather than
access violation. (error 80020009)
