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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
The following table shows the methods for this interface in alphabetical order.
Method | Description |
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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. |
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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. |
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Decrements the reference count for the calling interface on a object. If the reference count on the object falls to zero, the object is freed from memory. |
Remarks
To determine whether the platform supports this interface, see Determining Supported COM APIs.
Requirements
Header | unknwn.h, unknwn.idl |
Library | ole32.lib, uuid.lib |
Windows Embedded CE | Windows CE 1.0 and later |
Windows Mobile | Windows Mobile Version 5.0 and later |
See Also
Reference
IUnknown::AddRefIUnknown::QueryInterface
IUnknown::Release