ManagementEventWatcher.Scope Egenskap

public:
 property System::Management::ManagementScope ^ Scope { System::Management::ManagementScope ^ get(); void set(System::Management::ManagementScope ^ value); };

public System.Management.ManagementScope Scope { get; set; }

member this.Scope : System.Management.ManagementScope with get, set

Public Property Scope As ManagementScope

Egenskapsvärde

Omfånget där du kan titta efter händelser.

Exempel

I följande exempel visas hur klienten får ett meddelande när en instans av Win32_Process skapas eftersom händelseklassen är __InstanceCreationEvent. Mer information finns i dokumentationen Windows Management Instrumentation. Klienten tar emot händelser synkront genom att anropa WaitForNextEvent metoden. Det här exemplet kan testas genom att starta en process, till exempel Anteckningar, medan exempelkoden körs.

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;
        watcher.Scope = new ManagementScope("root\\CIMV2");
        // 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
        watcher.Scope = New ManagementScope("root\CIMV2")
        ' 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

Kommentarer

Egenskapsvärde

Omfånget där du ska titta efter händelser (namnområde eller omfång).

.NET Framework-säkerhet

Fullständigt förtroende för den omedelbara uppringaren. Den här medlemmen kan inte användas av delvis betrodd kod. Mer information finns i Använda bibliotek från delvis betrodd kod.