Represents the method that handles the OnAction event.

[Visual Basic .NET]
Public Delegate Sub OnActionEventHandler ( _
    ByVal action As esriARAction, _
    ByVal data As Object, _
    ByRef suppressAction As Boolean _
)

[C#]
public delegate void OnActionEventHandler (
    esriARAction action,
    object data,
    ref bool suppressAction
);