IMFMediaEventQueue::QueueEventParamUnk method (mfobjects.h)

Creates an event, sets an IUnknown pointer as the event data, and puts the event in the queue.


HRESULT QueueEventParamUnk(
  [in] MediaEventType met,
  [in] REFGUID        guidExtendedType,
  [in] HRESULT        hrStatus,
  [in] IUnknown       *pUnk


[in] met

Specifies the event type of the event to be added to the queue. The event type is returned by the event's IMFMediaEvent::GetType method. For a list of event types, see Media Foundation Events.

[in] guidExtendedType

The extended type of the event. If the event does not have an extended type, use the value GUID_NULL. The extended type is returned by the event's IMFMediaEvent::GetExtendedType method.

[in] hrStatus

A success or failure code indicating the status of the event. This value is returned by the event's IMFMediaEvent::GetStatus method.

[in] pUnk

Pointer to the IUnknown interface. The method sets this pointer as the event value. The pointer is returned by the event's IMFMediaEvent::GetValue method.

Return value

The method returns an HRESULT. Possible values include, but are not limited to, those in the following table.

Return code Description
The method succeeded.
The Shutdown method was called.


Call this method when your component needs to raise an event that contains an IUnknown pointer value and no attributes. If the event contains attributes, use IMFMediaEventQueue::QueueEvent instead.

This interface is available on the following platforms if the Windows Media Format 11 SDK redistributable components are installed:

  • Windows XP with Service Pack 2 (SP2) and later.
  • Windows XP Media Center Edition 2005 with KB900325 (Windows XP Media Center Edition 2005) and KB925766 (October 2006 Update Rollup for Windows XP Media Center Edition) installed.


Requirement Value
Minimum supported client Windows Vista [desktop apps | UWP apps]
Minimum supported server Windows Server 2008 [desktop apps | UWP apps]
Target Platform Windows
Header mfobjects.h (include Mfidl.h)
Library Mfuuid.lib

See also