ManagementEventWatcher Costruttori

Definizione

Spazio dei nomi:: System.Management

Assembly:: System.Management.dll

Pacchetto:: System.Management v11.0.0-preview.4.26230.115

Importante

Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.

Inizializza una nuova istanza della classe ManagementEventWatcher.

Overload

Nome	Descrizione
ManagementEventWatcher()	Inizializza una nuova istanza della classe ManagementEventWatcher. Per un'ulteriore inizializzazione, impostare le proprietà sull'oggetto . Si tratta del costruttore senza parametri.
ManagementEventWatcher(EventQuery)	Inizializza una nuova istanza della ManagementEventWatcher classe quando viene assegnata una query di evento WMI.
ManagementEventWatcher(String)	Inizializza una nuova istanza della ManagementEventWatcher classe quando viene assegnata una query di evento WMI sotto forma di stringa.
ManagementEventWatcher(ManagementScope, EventQuery)	Inizializza una nuova istanza della ManagementEventWatcher classe in ascolto degli eventi conformi alla query di evento WMI specificata.
ManagementEventWatcher(String, String)	Inizializza una nuova istanza della ManagementEventWatcher classe in ascolto degli eventi conformi alla query di evento WMI specificata. Per questa variante, la query e l'ambito vengono specificati come stringhe.
ManagementEventWatcher(ManagementScope, EventQuery, EventWatcherOptions)	Inizializza una nuova istanza della ManagementEventWatcher classe in ascolto degli eventi conformi alla query evento WMI specificata, in base alle opzioni specificate. Per questa variante, la query e l'ambito sono oggetti specificati. L'oggetto opzioni può specificare opzioni quali timeout e informazioni di contesto.
ManagementEventWatcher(String, String, EventWatcherOptions)	Inizializza una nuova istanza della ManagementEventWatcher classe in ascolto degli eventi conformi alla query evento WMI specificata, in base alle opzioni specificate. Per questa variante, la query e l'ambito vengono specificati come stringhe. L'oggetto opzioni può specificare opzioni come un timeout e informazioni di contesto.

ManagementEventWatcher()

Origine:: ManagementEventWatcher.cs

Origine:: ManagementEventWatcher.cs

Origine:: ManagementEventWatcher.cs

Origine:: ManagementEventWatcher.cs

Inizializza una nuova istanza della classe ManagementEventWatcher. Per un'ulteriore inizializzazione, impostare le proprietà sull'oggetto . Si tratta del costruttore senza parametri.

public:
 ManagementEventWatcher();

public ManagementEventWatcher();

Public Sub New ()

Esempio

Nell'esempio seguente viene illustrato come il client riceve la notifica quando viene creata un'istanza di Win32_Process perché la classe di evento è __InstanceCreationEvent. Per altre informazioni, vedere la documentazione Windows Management Instrumentation. Il client riceve gli eventi in modo sincrono chiamando il WaitForNextEvent metodo . Questo esempio può essere testato avviando un processo, ad esempio Blocco note, mentre il codice di esempio è in esecuzione.

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
        WqlEventQuery query =
            new WqlEventQuery("__InstanceCreationEvent",
            new TimeSpan(0,0,1),
            "TargetInstance isa \"Win32_Process\"");

        // Initialize an event watcher and subscribe to events
        // that match this query
        ManagementEventWatcher watcher =
            new ManagementEventWatcher();
        watcher.Query = 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 WqlEventQuery( _
            "__InstanceCreationEvent", _
            New TimeSpan(0, 0, 1), _
            "TargetInstance isa ""Win32_Process""")

        ' Initialize an event watcher and subscribe to events 
        ' that match this query
        Dim watcher As New ManagementEventWatcher
        watcher.Query = query
        ' times 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.")
        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

Commenti

Sicurezza di .NET Framework

Attendibilità totale per il chiamante immediato. Questo membro non può essere utilizzato da codice parzialmente attendibile. Per altre informazioni, vedere Uso di librerie da codice parzialmente attendibile.

Si applica a

ManagementEventWatcher(EventQuery)

Origine:: ManagementEventWatcher.cs

Origine:: ManagementEventWatcher.cs

Origine:: ManagementEventWatcher.cs

Origine:: ManagementEventWatcher.cs

Inizializza una nuova istanza della ManagementEventWatcher classe quando viene assegnata una query di evento WMI.

public:
 ManagementEventWatcher(System::Management::EventQuery ^ query);

public ManagementEventWatcher(System.Management.EventQuery query);

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

Public Sub New (query As EventQuery)

Parametri

query: EventQuery

Oggetto EventQuery che rappresenta una query di evento WMI, che determina gli eventi per i quali il watcher sarà in ascolto.

Esempio

In questo esempio di codice, il client riceve una notifica quando viene creata un'istanza di Win32_Process perché la classe di evento è __InstanceCreationEvent. Per altre informazioni, vedere la documentazione Windows Management Instrumentation. Il client riceve gli eventi in modo sincrono chiamando il WaitForNextEvent metodo . Questo esempio può essere testato avviando un processo, ad esempio Blocco note, mentre il codice di esempio è in esecuzione.

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
        string query =
            "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(new EventQuery(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 String
        query = "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(New EventQuery( _
        query))

        ' times 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.")
        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

Commenti

Lo spazio dei nomi in cui il watcher sarà in ascolto degli eventi è lo spazio dei nomi predefinito attualmente impostato.

Sicurezza di .NET Framework

Si applica a

ManagementEventWatcher(String)

Origine:: ManagementEventWatcher.cs

Origine:: ManagementEventWatcher.cs

Origine:: ManagementEventWatcher.cs

Origine:: ManagementEventWatcher.cs

Inizializza una nuova istanza della ManagementEventWatcher classe quando viene assegnata una query di evento WMI sotto forma di stringa.

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

public ManagementEventWatcher(string query);

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

Public Sub New (query As String)

Parametri

query: String

Query evento WMI, che definisce gli eventi per i quali il watcher sarà in ascolto.

Esempio

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
        string query =
            "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 String
        query = "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, 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.")
        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

Commenti

Lo spazio dei nomi in cui il watcher sarà in ascolto degli eventi è lo spazio dei nomi predefinito attualmente impostato.

Sicurezza di .NET Framework

Si applica a

ManagementEventWatcher(ManagementScope, EventQuery)

Origine:: ManagementEventWatcher.cs

Origine:: ManagementEventWatcher.cs

Origine:: ManagementEventWatcher.cs

Origine:: ManagementEventWatcher.cs

Inizializza una nuova istanza della ManagementEventWatcher classe in ascolto degli eventi conformi alla query di evento WMI specificata.

public:
 ManagementEventWatcher(System::Management::ManagementScope ^ scope, System::Management::EventQuery ^ query);

public ManagementEventWatcher(System.Management.ManagementScope scope, System.Management.EventQuery query);

new System.Management.ManagementEventWatcher : System.Management.ManagementScope * System.Management.EventQuery -> System.Management.ManagementEventWatcher

Public Sub New (scope As ManagementScope, query As EventQuery)

Parametri

scope: ManagementScope

Oggetto ManagementScope che rappresenta l'ambito (spazio dei nomi) in cui il watcher rimarrà in ascolto degli eventi.

query: EventQuery

Oggetto EventQuery che rappresenta una query di evento WMI, che determina gli eventi per i quali il watcher sarà in ascolto.

Esempio

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
        string query =
            "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(
            new ManagementScope("root\\CIMV2"),
            new EventQuery(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 String
        query = "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( _
            New ManagementScope("root\CIMV2"), _
            New EventQuery(query))

        ' times 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.")
        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

Commenti

Sicurezza di .NET Framework

Si applica a

ManagementEventWatcher(String, String)

Origine:: ManagementEventWatcher.cs

Origine:: ManagementEventWatcher.cs

Origine:: ManagementEventWatcher.cs

Origine:: ManagementEventWatcher.cs

Inizializza una nuova istanza della ManagementEventWatcher classe in ascolto degli eventi conformi alla query di evento WMI specificata. Per questa variante, la query e l'ambito vengono specificati come stringhe.

public:
 ManagementEventWatcher(System::String ^ scope, System::String ^ query);

public ManagementEventWatcher(string scope, string query);

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

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

Parametri

scope: String

Ambito di gestione (spazio dei nomi) in cui il watcher ascolterà gli eventi.

query: String

Query che definisce gli eventi per i quali il watcher sarà in ascolto.

Esempio

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
        string query =
            "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("root\\CIMV2",
            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 String
        query = "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( _
            "root\CIMV2", query)

        ' times 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.")
        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

Commenti

Sicurezza di .NET Framework

Si applica a

ManagementEventWatcher(ManagementScope, EventQuery, EventWatcherOptions)

Origine:: ManagementEventWatcher.cs

Origine:: ManagementEventWatcher.cs

Origine:: ManagementEventWatcher.cs

Origine:: ManagementEventWatcher.cs

Inizializza una nuova istanza della ManagementEventWatcher classe in ascolto degli eventi conformi alla query evento WMI specificata, in base alle opzioni specificate. Per questa variante, la query e l'ambito sono oggetti specificati. L'oggetto opzioni può specificare opzioni quali timeout e informazioni di contesto.

public:
 ManagementEventWatcher(System::Management::ManagementScope ^ scope, System::Management::EventQuery ^ query, System::Management::EventWatcherOptions ^ options);

public ManagementEventWatcher(System.Management.ManagementScope scope, System.Management.EventQuery query, System.Management.EventWatcherOptions options);

new System.Management.ManagementEventWatcher : System.Management.ManagementScope * System.Management.EventQuery * System.Management.EventWatcherOptions -> System.Management.ManagementEventWatcher

Public Sub New (scope As ManagementScope, query As EventQuery, options As EventWatcherOptions)

Parametri

scope: ManagementScope

Oggetto ManagementScope che rappresenta l'ambito (spazio dei nomi) in cui il watcher rimarrà in ascolto degli eventi.

query: EventQuery

Oggetto EventQuery che rappresenta una query di evento WMI, che determina gli eventi per i quali il watcher sarà in ascolto.

options: EventWatcherOptions

Oggetto EventWatcherOptions che rappresenta opzioni aggiuntive utilizzate per controllare gli eventi.

Esempio

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
        string query =
            "SELECT * FROM __InstanceCreationEvent "
            + "WITHIN 1 WHERE " +
            "TargetInstance isa \"Win32_Process\"";

        // Event options
        // blockSize = 1, so wait for 1 event to return
        EventWatcherOptions options = new EventWatcherOptions(
            null, TimeSpan.MaxValue, 1);

        // Initialize an event watcher and subscribe to events
        // that match this query
        ManagementEventWatcher watcher =
            new ManagementEventWatcher(
            new ManagementScope("root\\CIMV2"),
            new EventQuery(query), options);

        // 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 String
        query = "SELECT * FROM __InstanceCreationEvent " _
            & "WITHIN 1 WHERE " & _
            "TargetInstance isa ""Win32_Process"""

        ' Event options
        ' blockSize = 1, so wait for 1 event to return
        Dim options As New EventWatcherOptions( _
            Nothing, TimeSpan.MaxValue, 1)


        ' Initialize an event watcher and subscribe to events 
        ' that match this query
        Dim watcher As New ManagementEventWatcher( _
            New ManagementScope("root\CIMV2"), _
            New EventQuery(query), _
            options)

        ' 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

Commenti

Sicurezza di .NET Framework

Si applica a

ManagementEventWatcher(String, String, EventWatcherOptions)

Origine:: ManagementEventWatcher.cs

Origine:: ManagementEventWatcher.cs

Origine:: ManagementEventWatcher.cs

Origine:: ManagementEventWatcher.cs

Inizializza una nuova istanza della ManagementEventWatcher classe in ascolto degli eventi conformi alla query evento WMI specificata, in base alle opzioni specificate. Per questa variante, la query e l'ambito vengono specificati come stringhe. L'oggetto opzioni può specificare opzioni come un timeout e informazioni di contesto.

public:
 ManagementEventWatcher(System::String ^ scope, System::String ^ query, System::Management::EventWatcherOptions ^ options);

public ManagementEventWatcher(string scope, string query, System.Management.EventWatcherOptions options);

new System.Management.ManagementEventWatcher : string * string * System.Management.EventWatcherOptions -> System.Management.ManagementEventWatcher

Public Sub New (scope As String, query As String, options As EventWatcherOptions)

Parametri

scope: String

Ambito di gestione (spazio dei nomi) in cui il watcher ascolterà gli eventi.

query: String

Query che definisce gli eventi per i quali il watcher sarà in ascolto.

options: EventWatcherOptions

Oggetto EventWatcherOptions che rappresenta opzioni aggiuntive utilizzate per controllare gli eventi.

Esempio

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
        string query =
            "SELECT * FROM __InstanceCreationEvent "
            + "WITHIN 1 WHERE " +
            "TargetInstance isa \"Win32_Process\"";

        // Event options
        // blockSize = 1, so wait for 1 event to return
        EventWatcherOptions options = new EventWatcherOptions(
            null, TimeSpan.MaxValue, 1);

        // Initialize an event watcher and subscribe to events
        // that match this query
        ManagementEventWatcher watcher =
            new ManagementEventWatcher(
            new ManagementScope("root\\CIMV2"),
            new EventQuery(query), options);

        // 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 String
        query = "SELECT * FROM __InstanceCreationEvent " _
            & "WITHIN 1 WHERE " & _
            "TargetInstance isa ""Win32_Process"""

        ' Event options
        ' blockSize = 1, so wait for 1 event to return
        Dim options As New EventWatcherOptions( _
            Nothing, TimeSpan.MaxValue, 1)


        ' Initialize an event watcher and subscribe to events 
        ' that match this query
        Dim watcher As New ManagementEventWatcher( _
            "root\CIMV2", _
            query, _
            options)

        ' 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

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