IControlChangeNotify::OnNotify method

The OnNotify method notifies the client when the status of a connector or subunit changes.


  [in] DWORD   dwSenderProcessId,
  [in] LPCGUID pguidEventContext


dwSenderProcessId [in]

The process ID of the client that changed the state of the control. If a notification is generated by a hardware event, this process ID will differ from the client's process ID. For more information, see Remarks.

pguidEventContext [in]

A pointer to the context GUID for the control-change event. The client that initiates the control change supplies this GUID. For more information, see Remarks.

Return value

If the method succeeds, it returns S_OK. If it fails, it returns an error code.


A client can use this method to keep track of control changes made by other processes and by the hardware. However, a client that changes a control setting can typically disregard the notification that the control change generates. In its implementation of the OnNotify method, a client can inspect the dwSenderProcessId and pguidEventContext parameters to discover whether it or another client is the source of the control-change event.


Minimum supported client

Windows Vista [desktop apps only]

Minimum supported server

Windows Server 2008 [desktop apps only]



See also

IControlChangeNotify Interface