IDirectDrawSurface::QueryInterface

HRESULT QueryInterface(REFIID riid, LPVOID FAR * ppvObj);

Determines if the DirectDrawSurface 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 DirectDraw.

·Returns DD_OK if successful, or one of the following error values otherwise:

DDERR_INVALIDOBJECT DDERR_INVALIDPARAMS

DDERR_OUTOFMEMORY

riid

Reference identifier of the interface being requested.

ppvObj

Address of a pointer that will 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 IDirectDrawSurface::QueryInterface method allows DirectDrawSurface objects to be extended by Microsoft and third parties without interfering with each other's existing or future functionality.