# IViewObject::SetAdvise

Sets up a connection between the view object and an advise sink so that the advise sink can be notified about changes in the object’s view.

HRESULT SetAdvise(

DWORD dwAspect, | //View for which notification is being requested
DWORD advf, | //Information about the advise sink
IAdviseSink * pAdvSink | //Pointer to the advise sink that is to receive change notifications
); |

Parameters

dwAspect
  [in] View for which the advisory connection is being set up. Valid values are taken from the enumeration DVASPECT. See the DVASPECT enumeration for more information.
advf
  [in] Contains a group of flags for controlling the advisory connection. Valid values are from the enumeration ADVF. However, only some of the possible ADVF values are relevant for this method. The following table briefly describes the relevant values. See the ADVF enumeration for a more detailed description.

  ADVF Value | Description
  ADVF_ONLYONCE | Causes the advisory connection to be destroyed after the first notification is sent.
  ADVF_PRIMEFIRST | Causes an initial notification to be sent regardless of whether data has changed from its current state.

  Note that the ADVF_ONLYONCE and ADVF_PRIMEFIRST can be combined to provide an asynchronous call to IDataObject::GetData.

pAdvSink
  [out] Pointer to the IAdviseSink interface on the advisory sink that is to be informed of changes. A NULL value deletes any existing advisory connection.

Return Values

This method supports the standard return values E_INVALIDARG and E_OUTOFMEMORY, as well as the following:

S_OK
  The advisory connection was successfully established.
OLE_E_ADVISENOTSUPPORTED
  Advisory notifications are not supported.
DV_E_DVASPECT
  Invalid value for dwAspect.

Remarks

A container application that is requesting a draw operation on a view object can also register with the IViewObject::SetAdvise method to be notified when the presentation of the view object changes. To find out about when an object’s underlying data changes, you must call IDataObject::DAdvise separately.

To remove an existing advisory connection, call the IViewObject::SetAdvise method with pAdvSink set to NULL.

If the view object changes, a call is made to the appropriate advise sink through its IAdviseSink::OnViewChange method.

At any time, a given view object can support only one advisory connection. Therefore, when IViewObject::SetAdvise is called and the view object is already holding on to an advise sink pointer, OLE releases the existing pointer before the new one is registered.

See Also

ADVF, IAdviseSink, IViewObject::GetAdvise