WqlEventQuery クラス
WMI イベント クエリを WQL 形式で表します。
この型のすべてのメンバの一覧については、WqlEventQuery メンバ を参照してください。
System.Object
System.Management.ManagementQuery
System.Management.EventQuery
System.Management.WqlEventQuery
Public Class WqlEventQuery
Inherits EventQuery
[C#]
public class WqlEventQuery : EventQuery
[C++]
public __gc class WqlEventQuery : public EventQuery
[JScript]
public class WqlEventQuery extends EventQuery
スレッドセーフ
この型の public static (Visual Basicでは Shared) のすべてのメンバは、マルチスレッド操作で安全に使用できます。インスタンスのメンバの場合は、スレッドセーフであるとは限りません。
使用例
using System;
using System.Management;
// This sample demonstrates how to subscribe to an event
// using a WQL event query.
class Sample_EventQuery
{
public static int Main(string[] args)
{
//For this example, we make sure we have an arbitrary class on root\default
ManagementClass newClass = new ManagementClass(
"root\\default",
String.Empty,
null);
newClass["__Class"] = "TestWql";
newClass.Put();
//Create a query object for watching for class deletion events
WqlEventQuery eventQuery = new WqlEventQuery("select * from __classdeletionevent");
//Initialize an event watcher object with this query
ManagementEventWatcher watcher = new ManagementEventWatcher(
new ManagementScope("root/default"),
eventQuery);
//Set up a handler for incoming events
MyHandler handler = new MyHandler();
watcher.EventArrived += new EventArrivedEventHandler(handler.Arrived);
//Start watching for events
watcher.Start();
//For this example, we delete the class to trigger an event
newClass.Delete();
//Nothing better to do - we loop to wait for an event to arrive.
while (!handler.IsArrived) {
System.Threading.Thread.Sleep(1000);
}
//In this example we only want to wait for one event, so we can stop watching
watcher.Stop();
return 0;
}
public class MyHandler
{
private bool isArrived = false;
//Handles the event when it arrives
public void Arrived(object sender, EventArrivedEventArgs e) {
ManagementBaseObject eventArg = (ManagementBaseObject)(e.NewEvent["TargetClass"]);
Console.WriteLine("Class Deleted = " + eventArg["__CLASS"]);
isArrived = true;
}
//Used to determine whether the event has arrived or not.
public bool IsArrived {
get {
return isArrived;
}
}
}
}
[Visual Basic]
Imports System
Imports System.Management
' This sample demonstrates how to subscribe an event
' using a WQL event query.
Class Sample_EventQuery
Public Shared Sub Main()
'For this example, we make sure we have an arbitrary class on root\default
Dim newClass As New ManagementClass( _
"root\default", _
String.Empty, Nothing)
newClass("__Class") = "TestWql"
newClass.Put()
'Create a query object for watching for class deletion events
Dim eventQuery As New WqlEventQuery("select * from __classdeletionevent")
'Initialize an event watcher object with this query
Dim watcher As New ManagementEventWatcher( _
New ManagementScope("root/default"), _
eventQuery)
'Set up a handler for incoming events
Dim handler As New MyHandler()
AddHandler watcher.EventArrived, AddressOf handler.Arrived
'Start watching for events
watcher.Start()
'For this example, we delete the class to trigger an event
newClass.Delete()
'Nothing better to do - we loop to wait for an event to arrive.
While Not handler.IsArrived
Console.Write("0")
System.Threading.Thread.Sleep(1000)
End While
'In this example we only want to wait for one event, so we can stop watching
watcher.Stop()
End Sub
Public Class MyHandler
Private _isArrived As Boolean = False
'Handles the event when it arrives
Public Sub Arrived(sender As Object, e As EventArrivedEventArgs)
Dim eventArg As ManagementBaseObject = CType( _
e.NewEvent("TargetClass"), _
ManagementBaseObject)
Console.WriteLine(("Class Deleted = " + eventArg("__CLASS")))
_isArrived = True
End Sub
'Used to determine whether the event has arrived or not.
Public ReadOnly Property IsArrived() As Boolean
Get
Return _isArrived
End Get
End Property
End Class
End Class
[C++, JScript] C++ および JScript のサンプルはありません。Visual Basic および C# のサンプルを表示するには、このページの左上隅にある言語のフィルタ ボタン をクリックします。
必要条件
名前空間: System.Management
プラットフォーム: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 ファミリ
アセンブリ: System.Management (System.Management.dll 内)