CoRevokeClassObject function (combaseapi.h)

Article
10/13/2021

Informs OLE that a class object, previously registered with the CoRegisterClassObject function, is no longer available for use.

Syntax

HRESULT CoRevokeClassObject(
  [in] DWORD dwRegister
);

Parameters

[in] dwRegister

A token previously returned from the CoRegisterClassObject function.

Return value

This function can return the standard return values E_INVALIDARG, E_OUTOFMEMORY, and E_UNEXPECTED, as well as the following values.

Return code	Description
S_OK	The class object was revoked successfully.

Remarks

A successful call to CoRevokeClassObject means that the class object has been removed from the global class object table (although it does not release the class object). If other clients still have pointers to the class object and have caused the reference count to be incremented by calls to IUnknown::AddRef, the reference count will not be zero. When this occurs, applications may benefit if subsequent calls (with the obvious exceptions of AddRef and IUnknown::Release) to the class object fail. Note that CoRegisterClassObject calls AddRef and CoRevokeClassObject calls Release, so the two functions form an AddRef/Release pair.

An object application must call CoRevokeClassObject to revoke registered class objects before exiting the program. Class object implementers should call CoRevokeClassObject as part of the release sequence. You must specifically revoke the class object even when you have specified the flags value REGCLS_SINGLEUSE in a call to CoRegisterClassObject, indicating that only one application can connect to the class object.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps \| UWP apps]
Minimum supported server	Windows 2000 Server [desktop apps \| UWP apps]
Target Platform	Windows
Header	combaseapi.h (include Objbase.h)
Library	Ole32.lib
DLL	Ole32.dll