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Important This document may not represent best practices for current development, links to downloads and other resources may no longer be valid. Current recommended version can be found here.


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Provides an alternative way to invoke the OLE method IUnknown::AddRef.

Header file:


Implemented by:


Called by:

Client applications and service providers

  LPVOID punk


[in] Pointer to an interface derived from the IUnknown interface, in other words any MAPI interface.


The call succeeded and has returned the expected value or values.


An error of unexpected or unknown origin prevented the operation from completing.

UlAddRef returns the value returned by the IUnknown::AddRef method, which is the new value of the reference count for the interface. The value is nonzero.

For more information about IUnknown::AddRef, see Implementing the IUnknown Interface.

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