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ManagementOperationObserver Class

Manages asynchronous operations and handles management information and events received asynchronously.

Namespace: System.Management
Assembly: System.Management (in

public class ManagementOperationObserver
public class ManagementOperationObserver
public class ManagementOperationObserver
Not applicable.

The following example demonstrates how to perform an asynchronous instance enumeration. The example uses the ManagementOperationObserver class to handle management information and events asynchronously.

using System;
using System.Management;

// This example demonstrates how
// to perform an asynchronous instance enumeration.

public class EnumerateInstancesAsync 
    public EnumerateInstancesAsync()
        // Enumerate asynchronously using Object Searcher
        // ===============================================

        // Instantiate an object searcher with the query
        ManagementObjectSearcher searcher = 
            new ManagementObjectSearcher(new

        // Create a results watcher object,
        // and handler for results and completion
        ManagementOperationObserver results = new
        // Attach handler to events for results and completion
        results.ObjectReady += new 
        results.Completed += new 

        // Call the asynchronous overload of Get()
        // to start the enumeration
        // Do something else while results
        // arrive asynchronously
        while (!this.Completed)
            System.Threading.Thread.Sleep (1000);

    private bool isCompleted = false;

    private void NewObject(object sender,
        ObjectReadyEventArgs obj) 
        Console.WriteLine("Service : {0}, State = {1}", 

    private bool Completed 
            return isCompleted;
    private void Reset()   
        isCompleted = false;

    private void Done(object sender,
        CompletedEventArgs obj) 
        isCompleted = true;

    public static void Main()
        EnumerateInstancesAsync example =
            new EnumerateInstancesAsync();



Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 98, Windows Server 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 Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0