EventArrivedEventHandler Delegate
Assembly: System.Management (in system.management.dll)
'Declaration Public Delegate Sub EventArrivedEventHandler ( _ sender As Object, _ e As EventArrivedEventArgs _ ) 'Usage Dim instance As New EventArrivedEventHandler(AddressOf HandlerMethod)
/** @delegate */ public delegate void EventArrivedEventHandler ( Object sender, EventArrivedEventArgs e )
JScript supports the use of delegates, but not the declaration of new ones.
Parameters
- sender
The instance of the object for which to invoke this method.
- e
The EventArrivedEventArgs that specifies the reason the event was invoked.
The following asynchronous example sets up a WMI timer to raise an event every second, and removes it when no longer needed. The ManagementEventWatcher defines several .NET Framework events which are raised when WMI events are delivered. Delegates are attached to these events for handling the incoming data.
Imports System Imports System.Management ' This example shows asynchronous consumption of events. ' In this example you are listening for timer events. ' The first part of the example sets up the timer. Public Class EventWatcherAsync Public Sub New() ' Set up a timer to raise events every 1 second '============================================= Dim timerClass As New ManagementClass( _ "__IntervalTimerInstruction") Dim timer As ManagementObject = _ timerClass.CreateInstance() timer("TimerId") = "Timer1" timer("IntervalBetweenEvents") = 1000 timer.Put() ' Set up the event consumer '========================== ' Create event query to receive timer events Dim query As New WqlEventQuery("__TimerEvent", _ "TimerId=""Timer1""") ' Initialize an event watcher and subscribe to ' events that match this query Dim watcher As New ManagementEventWatcher(query) ' Set up a listener for events AddHandler watcher.EventArrived, _ AddressOf Me.HandleEvent ' Start listening watcher.Start() ' Do something in the meantime System.Threading.Thread.Sleep(10000) ' Stop listening watcher.Stop() End Sub Private Sub HandleEvent(ByVal sender As Object, _ ByVal e As EventArrivedEventArgs) Console.WriteLine("Event arrived !") End Sub Public Overloads Shared Function _ Main(ByVal args() As String) As Integer 'start the event watcher Dim eventWatcher As New EventWatcherAsync Return 0 End Function End Class
Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.