HRESULT QueryInterface(REFIID riid, LPVOID * ppvObj);
Determines if the DirectPlay object supports a particular COM interface. If it does, the system increases the reference count for the object, and the application can begin using that interface immediately. This method is part of the IUnknown interface inherited by DirectPlay.
·Returns DP_OK if successful, or one of the following error values otherwise:
DPERR_INVALIDOBJECT DPERR_INVALIDPARAMS
riid
Reference identifier of the interface being requested.
ppvObj
Address for a pointer to be filled with the interface pointer if the query is successful.
If the application does not need to use the interface retrieved by a call to this method, it must call the Release method for that interface to free it. The IDirectPlay::QueryInterface method allows DirectPlay objects to be extended by Microsoft and third parties without interfering with each other's existing or future functionality.