IUIAutomation::AddPropertyChangedEventHandler method (uiautomationclient.h)

Registers a method that handles and array of property-changed events.

Syntax

HRESULT AddPropertyChangedEventHandler(
  [in] IUIAutomationElement                     *element,
  [in] TreeScope                                scope,
  [in] IUIAutomationCacheRequest                *cacheRequest,
  [in] IUIAutomationPropertyChangedEventHandler *handler,
  [in] SAFEARRAY                                *propertyArray
);

Parameters

[in] element

Type: IUIAutomationElement*

A pointer to the UI Automation element associated with the event handler.

[in] scope

Type: TreeScope

The scope of events to be handled; that is, whether they are on the element itself, or on its ancestors and children.

[in] cacheRequest

Type: IUIAutomationCacheRequest*

A pointer to a cache request, or NULL if no caching is wanted.

[in] handler

Type: IUIAutomationPropertyChangedEventHandler*

A pointer to the object that handles the event.

[in] propertyArray

Type: SAFEARRAY*

A pointer to the UI Automation properties of interest. For a list of property IDs, see Property Identifiers.

Return value

Type: HRESULT

If this method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code.

Remarks

The UI item specified by element might not support the properties specified by the propertyArray parameter.

A UI Automation client should not use multiple threads to add or remove event handlers. Unexpected behavior can result if one event handler is being added or removed while another is being added or removed in the same client process.

Requirements

See also

AddPropertyChangedEventHandlerNativeArray

Best Practices for Using Safe Arrays

Caching UI Automation Properties and Control Patterns

Conceptual

IUIAutomation

Reference

RemoveAllEventHandlers

RemovePropertyChangedEventHandler

Subscribing to UI Automation Events

Understanding Threading Issues