This (enormous) enumeration is a part of the accessibility framework, that allows you to support users who need assistance with particular aspects of the UI, perhaps as the result of a disability. Microsoft also recommends the use of these APIs for automated testing. The elements of this enumeration list more or less anything and everything that could possibly happen to a control, from properties changing to creation and destruction.

The enumeration is used by the AccessibleObject to notify accessibility clients that things are occurring of which they should take note (perhaps updating their own UI or controlling an external device such as a Braille reader). See AccessibleObject for a discussion of the accessibility framework.

public enum AccessibleEvents {
   SystemSound = 1,
   SystemAlert = 2,
   SystemForeground = 3,
   SystemMenuStart = 4,
   SystemMenuEnd = 5,
   SystemMenuPopupStart = 6,
   SystemMenuPopupEnd = 7,
   SystemCaptureStart = 8,
   SystemCaptureEnd = 9,
   SystemMoveSizeStart = 10,
   SystemMoveSizeEnd = 11,
   SystemContextHelpStart = 12,
   SystemContextHelpEnd = 13,
   SystemDragDropStart = 14,
   SystemDragDropEnd = 15,
   SystemDialogStart = 16,
   SystemDialogEnd = 17,
   SystemScrollingStart = 18,
   SystemScrollingEnd = 19,
   SystemSwitchStart = 20,
   SystemSwitchEnd = 21,
   SystemMinimizeStart = 22,
   SystemMinimizeEnd = 23,
   Create = 32768,
   Destroy = 32769,
   Show = 32770,
   Hide = 32771,
   Reorder = 32772,
   Focus = 32773,
   Selection = 32774,
   SelectionAdd = 32775,
   SelectionRemove = 32776,
   SelectionWithin = 32777,
   StateChange = 32778,
   LocationChange = 32779,
   NameChange = 32780,
   DescriptionChange = 32781,
   ValueChange = 32782,
   ParentChange = 32783,
   HelpChange = 32784,
   DefaultActionChange = 32785,
   AcceleratorChange = 32786
}

Hierarchy

System.Object System.ValueType System.Enum(System.IComparabl, System.IFormattable, System.IConvertible) AccessibleEvents

Passed To

Control.AccessibilityNotifyClients(), ControlAccessibleObject.NotifyClients()