IWbemEventProviderQuerySink interface (wbemprov.h)

The IWbemEventProviderQuerySink interface is optionally implemented by event providers who want to know what kinds of event query filters are currently active to optimize performance.


The IWbemEventProviderQuerySink interface inherits from the IUnknown interface. IWbemEventProviderQuerySink also has these types of members:


The IWbemEventProviderQuerySink interface has these methods.


Call the IWbemEventProviderQuerySink::CancelQuery method whenever a logical event consumer cancels a relevant event query filter with Windows Management.

Call the IWbemEventProviderQuerySink::NewQuery method when a logical event consumer registers a relevant event query filter with Windows Management.


Although WMI calls the methods of IWbemEventProvider only one time after an event provider becomes active, WMI calls the methods of IWbemEventProviderQuerySink continuously, as appropriate. The provider can ignore all calls to IWbemEventProviderQuerySink methods as needed. This point is very important; supporting IWbemEventProviderQuerySink indicates that a provider will supply at least the events requested by queries.

A provider can also generate more events than requested, which WMI filters as appropriate. This functionality means you can implement IWbemEventProviderQuerySink and optimize processing without addressing all parts of the WMI Query Language (WQL). For instance, if a provider does not specifically handle a particular query, the provider can generate all possible events for the query.


Minimum supported client Windows Vista
Minimum supported server Windows Server 2008
Target Platform Windows
Header wbemprov.h (include Wbemidl.h)