IUnknown

Important:
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This interface enables clients to get pointers to other interfaces on a specified object through the IUnknown::QueryInterfacemethod, and manage the existence of the object through the IUnknown::AddRefand IUnknown::Releasemethods. All other COM interfaces are inherited, directly or indirectly, from IUnknown. Therefore, the three methods in IUnknownare the first entries in the Vtable for every interface.

Methods	Description
IUnknown::QueryInterface	Returns a pointer to a specified interface on an object to which a client currently holds an interface pointer. This method must call IUnknown::AddRefon the pointer it returns.
IUnknown::AddRef	Increments the reference count for an interface on an object. It should be called for every new copy of a pointer to an interface on a specified object.
IUnknown::Release	Decrements the reference count for the calling interface on a object. If the reference count on the object falls to 0, the object is freed from memory.

Requirements

Runs On	Versions	Defined in	Include	Link to
Windows CE OS	1.0 and later	Unknwn.h

Note This API is part of the complete Windows CE OS package as provided by Microsoft. The functionality of a particular platform is determined by the original equipment manufacturer (OEM) and some devices may not support this API.