IRawElementProviderAdviseEvents::AdviseEventAdded Method
Notifies the UI Automation provider when a UI Automation client begins listening for a specific event, including a property-changed event.
Syntax
HRESULT AdviseEventAdded( EVENTID eventId, SAFEARRAY *propertyIDs );
Parameters
- eventId
[in] The identifier of the event being added. For a list of event IDs, see Event Identifiers.- propertyIDs
[in] The address of a SAFEARRAY that contains the identifiers of properties being added, or NULL if the event listener being added is not listening for property events.
Return Value
Returns S_OK if successful, or an error value otherwise.
Remarks
This method enables the provider to reduce overhead by raising only events that are being listened for.
It is important for Microsoft UI Automation providers to treat the IRawElementProviderAdviseEvents::AdviseEventAdded like the AddRef method of the IUnknown interface. As long as AdviseEventAdded has been called more times than AdviseEventRemoved for a specific event or property, the provider should continue to raise corresponding events, because some clients are still listening. Alternatively, UI Automation providers can use the UiaClientsAreListening function to determine if at least one client is listening and, if so, raise all appropriate events.
See Also