EventQuery Konstruktoren

Referenz

Definition

Namespace:: System.Management

Assembly:: System.Management.dll

Paket:: System.Management v6.0.0

Paket:: System.Management v7.0.0

Paket:: System.Management v8.0.0

Paket:: System.Management v9.0.0-preview.2.24128.5

Wichtig

Einige Informationen beziehen sich auf Vorabversionen, die vor dem Release ggf. grundlegend überarbeitet werden. Microsoft übernimmt hinsichtlich der hier bereitgestellten Informationen keine Gewährleistungen, seien sie ausdrücklich oder konkludent.

Initialisiert eine neue Instanz der EventQuery-Klasse.

Überlädt

EventQuery()	Initialisiert eine neue Instanz der EventQuery-Klasse. Dies ist der parameterlose Konstruktor.
EventQuery(String)	Initialisiert eine neue Instanz der EventQuery-Klasse für die angegebene Abfrage.
EventQuery(String, String)	Initialisiert eine neue Instanz der EventQuery-Klasse für die angegebene Sprache und Abfrage.

EventQuery()

Quelle:: ManagementQuery.cs

Quelle:: ManagementQuery.cs

Quelle:: ManagementQuery.cs

Initialisiert eine neue Instanz der EventQuery-Klasse. Dies ist der parameterlose Konstruktor.

public:
 EventQuery();

public EventQuery ();

Public Sub New ()

Beispiele

Das folgende Beispiel zeigt, wie der Client eine Benachrichtigung empfängt, wenn eine instance von Win32_Process erstellt wird, da die Ereignisklasse __InstanceCreationEvent ist. Weitere Informationen finden Sie in der Dokumentation zur Windows-Verwaltungsinstrumentation . Der Client empfängt Ereignisse synchron durch Aufrufen der WaitForNextEvent-Methode. Während der Beispielcode ausgeführt wird, kann dieses Beispiel durch Starten eines Prozesses wie Editor getestet werden.

using System;
using System.Management;

// This example shows synchronous consumption of events.
// The client is blocked while waiting for events.

public class EventWatcherPolling
{
    public static int Main(string[] args)
    {
        // Create event query to be notified within 1 second of
        // a change in a service
        EventQuery query = new EventQuery();
        query.QueryString = "SELECT * FROM" +
            " __InstanceCreationEvent WITHIN 1 " +
            "WHERE TargetInstance isa \"Win32_Process\"";

        // Initialize an event watcher and subscribe to events
        // that match this query
        ManagementEventWatcher watcher =
            new ManagementEventWatcher(query);
        // times out watcher.WaitForNextEvent in 5 seconds
        watcher.Options.Timeout = new TimeSpan(0,0,5);

        // Block until the next event occurs
        // Note: this can be done in a loop if waiting for
        //        more than one occurrence
        Console.WriteLine(
            "Open an application (notepad.exe) to trigger an event.");
        ManagementBaseObject e = watcher.WaitForNextEvent();

        //Display information from the event
        Console.WriteLine(
            "Process {0} has been created, path is: {1}",
            ((ManagementBaseObject)e
            ["TargetInstance"])["Name"],
            ((ManagementBaseObject)e
            ["TargetInstance"])["ExecutablePath"]);

        //Cancel the subscription
        watcher.Stop();
        return 0;
    }
}

Imports System.Management

' This example shows synchronous consumption of events. 
' The client is blocked while waiting for events. 

Public Class EventWatcherPolling
    Public Overloads Shared Function _
        Main(ByVal args() As String) As Integer

        ' Create event query to be notified within 1 second of 
        ' a change in a service
        Dim query As New EventQuery
        query.QueryString = "SELECT * FROM" & _
            " __InstanceCreationEvent WITHIN 1 " & _
            "WHERE TargetInstance isa ""Win32_Process"""

        ' Initialize an event watcher and subscribe to events 
        ' that match this query
        Dim watcher As New ManagementEventWatcher(query)
        ' times watcher.WaitForNextEvent in 5 seconds
        watcher.Options.Timeout = New TimeSpan(0, 0, 50)

        ' Block until the next event occurs 
        ' Note: this can be done in a loop
        ' if waiting for more than one occurrence
        Console.WriteLine( _
          "Open an application (notepad.exe) to trigger an event.")
        Dim e As ManagementBaseObject = _
            watcher.WaitForNextEvent()

        'Display information from the event
        Console.WriteLine( _
            "Process {0} has created, path is: {1}", _
            CType(e("TargetInstance"), _
                ManagementBaseObject)("Name"), _
            CType(e("TargetInstance"), _
                ManagementBaseObject)("ExecutablePath"))

        'Cancel the subscription
        watcher.Stop()
        Return 0

    End Function 'Main
End Class

Hinweise

.NET Framework-Sicherheit

Volle Vertrauenswürdigkeit für den unmittelbaren Aufrufer. Dieser Member kann von nur teilweise vertrauenswürdigem Code nicht verwendet werden. Weitere Informationen finden Sie unter Verwenden von Bibliotheken aus teilweise vertrauenswürdigem Code.

Gilt für:

EventQuery(String)

Quelle:: ManagementQuery.cs

Quelle:: ManagementQuery.cs

Quelle:: ManagementQuery.cs

Initialisiert eine neue Instanz der EventQuery-Klasse für die angegebene Abfrage.

public:
 EventQuery(System::String ^ query);

public EventQuery (string query);

new System.Management.EventQuery : string -> System.Management.EventQuery

Public Sub New (query As String)

Parameter

query: String

Eine Textdarstellung der event query.

Beispiele

using System;
using System.Management;

// This example shows synchronous consumption of events.
// The client is blocked while waiting for events.

public class EventWatcherPolling
{
    public static int Main(string[] args)
    {
        // Create event query to be notified within 1 second of
        // a change in a service
        EventQuery query = new EventQuery(
            "SELECT * FROM" +
            " __InstanceCreationEvent WITHIN 1 " +
            "WHERE TargetInstance isa \"Win32_Process\"");

        // Initialize an event watcher and subscribe to events
        // that match this query
        ManagementEventWatcher watcher =
            new ManagementEventWatcher(query);
        // times out watcher.WaitForNextEvent in 5 seconds
        watcher.Options.Timeout = new TimeSpan(0,0,5);

        // Block until the next event occurs
        // Note: this can be done in a loop if waiting for
        //        more than one occurrence
        Console.WriteLine(
            "Open an application (notepad.exe) to trigger an event.");
        ManagementBaseObject e = watcher.WaitForNextEvent();

        //Display information from the event
        Console.WriteLine(
            "Process {0} has been created, path is: {1}",
            ((ManagementBaseObject)e
            ["TargetInstance"])["Name"],
            ((ManagementBaseObject)e
            ["TargetInstance"])["ExecutablePath"]);

        //Cancel the subscription
        watcher.Stop();
        return 0;
    }
}

Imports System.Management

' This example shows synchronous consumption of events. 
' The client is blocked while waiting for events. 

Public Class EventWatcherPolling
    Public Overloads Shared Function _
        Main(ByVal args() As String) As Integer

        ' Create event query to be notified within 1 second of 
        ' a change in a service
        Dim query As New EventQuery( _
            "SELECT * FROM" & _
            " __InstanceCreationEvent WITHIN 1 " & _
            "WHERE TargetInstance isa ""Win32_Process""")

        ' Initialize an event watcher and subscribe to events 
        ' that match this query
        Dim watcher As New ManagementEventWatcher(query)
        ' times watcher.WaitForNextEvent in 5 seconds
        watcher.Options.Timeout = New TimeSpan(0, 0, 50)

        ' Block until the next event occurs 
        ' Note: this can be done in a loop
        ' if waiting for more than one occurrence
        Console.WriteLine( _
          "Open an application (notepad.exe) to trigger an event.")
        Dim e As ManagementBaseObject = _
            watcher.WaitForNextEvent()

        'Display information from the event
        Console.WriteLine( _
            "Process {0} has created, path is: {1}", _
            CType(e("TargetInstance"), _
                ManagementBaseObject)("Name"), _
            CType(e("TargetInstance"), _
                ManagementBaseObject)("ExecutablePath"))

        'Cancel the subscription
        watcher.Stop()
        Return 0

    End Function 'Main
End Class

Hinweise

.NET Framework-Sicherheit

Gilt für:

EventQuery(String, String)

Quelle:: ManagementQuery.cs

Quelle:: ManagementQuery.cs

Quelle:: ManagementQuery.cs

Initialisiert eine neue Instanz der EventQuery-Klasse für die angegebene Sprache und Abfrage.

public:
 EventQuery(System::String ^ language, System::String ^ query);

public EventQuery (string language, string query);

new System.Management.EventQuery : string * string -> System.Management.EventQuery

Public Sub New (language As String, query As String)

Parameter

language: String

Die Sprache, in der die Abfragezeichenfolge angegeben ist.

query: String

Die Zeichenfolgendarstellung der Abfrage.

Beispiele

using System;
using System.Management;

// This example shows synchronous consumption of events.
// The client is blocked while waiting for events.

public class EventWatcherPolling
{
    public static int Main(string[] args)
    {
        // Create event query to be notified within 1 second of
        // a change in a service
        EventQuery query = new EventQuery("WQL",
            "SELECT * FROM" +
            " __InstanceCreationEvent WITHIN 1 " +
            "WHERE TargetInstance isa \"Win32_Process\"");

        // Initialize an event watcher and subscribe to events
        // that match this query
        ManagementEventWatcher watcher =
            new ManagementEventWatcher(query);
        // times out watcher.WaitForNextEvent in 5 seconds
        watcher.Options.Timeout = new TimeSpan(0,0,5);

        // Block until the next event occurs
        // Note: this can be done in a loop if waiting for
        //        more than one occurrence
        Console.WriteLine(
            "Open an application (notepad.exe) to trigger an event.");
        ManagementBaseObject e = watcher.WaitForNextEvent();

        //Display information from the event
        Console.WriteLine(
            "Process {0} has been created, path is: {1}",
            ((ManagementBaseObject)e
            ["TargetInstance"])["Name"],
            ((ManagementBaseObject)e
            ["TargetInstance"])["ExecutablePath"]);

        //Cancel the subscription
        watcher.Stop();
        return 0;
    }
}

Imports System.Management

' This example shows synchronous consumption of events. 
' The client is blocked while waiting for events. 

Public Class EventWatcherPolling
    Public Overloads Shared Function _
        Main(ByVal args() As String) As Integer

        ' Create event query to be notified within 1 second of 
        ' a change in a service
        Dim query As New EventQuery("WQL", _
            "SELECT * FROM" & _
            " __InstanceCreationEvent WITHIN 1 " & _
            "WHERE TargetInstance isa ""Win32_Process""")

        ' Initialize an event watcher and subscribe to events 
        ' that match this query
        Dim watcher As New ManagementEventWatcher(query)
        ' times watcher.WaitForNextEvent in 5 seconds
        watcher.Options.Timeout = New TimeSpan(0, 0, 50)

        ' Block until the next event occurs 
        ' Note: this can be done in a loop
        ' if waiting for more than one occurrence
        Console.WriteLine( _
          "Open an application (notepad.exe) to trigger an event.")
        Dim e As ManagementBaseObject = _
            watcher.WaitForNextEvent()

        'Display information from the event
        Console.WriteLine( _
            "Process {0} has created, path is: {1}", _
            CType(e("TargetInstance"), _
                ManagementBaseObject)("Name"), _
            CType(e("TargetInstance"), _
                ManagementBaseObject)("ExecutablePath"))

        'Cancel the subscription
        watcher.Stop()
        Return 0

    End Function 'Main
End Class

Hinweise

.NET Framework-Sicherheit

Gilt für:

Freigeben über

EventQuery Konstruktoren

Definition

Überlädt

EventQuery()

Beispiele

Hinweise

.NET Framework-Sicherheit

Gilt für:

EventQuery(String)

Parameter

Beispiele

Hinweise

.NET Framework-Sicherheit

Gilt für:

EventQuery(String, String)

Parameter

Beispiele

Hinweise

.NET Framework-Sicherheit

Gilt für:

Zusätzliche Ressourcen