WinEventProc

[This is preliminary documentation and subject to change.]

Application-defined callback function called by USER in response to events generated by an accessible object. This is a function prototype for conceptual presentation; actual callback functions in your code would accept the same parameters and return a VOID, but need not have an identical label.

VOID CALLBACK WinEventProc(
  HWINEVENTHOOK hWinEventHook,
  DWORD event,
  HWND hwnd,
  LONG idObject,
  LONG idChild,
  DWORD dwEventThread,
  DWORD dwmsEventTime
);
 

Parameters

hWinEventHook

Handle to an event hook. This value is specific to each instance of a WinEventProc function.

event

Value specifying the event that occurred. This value will be one of the event constants.

hwnd

Handle to the window generating the event, or NULL if no window is associated with the event.

idObject

Value identifying the top-level object associated with the event. This will be one of the object identifier constants or a custom object ID. If this value is OBJID_WINDOW, then the object is the window itself.

idChild

ID of the child element triggering the event, or CHILDID_SELF if the event is for the object itself.

dwEventThread

ID of the thread generating the event. This value is provided for background information only.

dwmsEventTime

Value specifying the time of the event, in milliseconds.

Remarks

An Active Accessibility client requests specific types of event notifications by calling the SetWinEventHook function.

You can create multiple callback functions to handle different events. For more information, see About the WinEventProc Callback Function.

See Also

WINEVENTPROC, SetWinEventHook