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ManagementOperationObserver Class

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

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

'Declaration
Public Class ManagementOperationObserver
'Usage
Dim instance As ManagementOperationObserver

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

Imports System
Imports System.Management

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

Public Class EnumerateInstancesAsync

    Public Sub New()

        Me.isCompleted = False 

        ' Enumerate asynchronously using Object Searcher 
        ' =============================================== 

        ' Instantiate an object searcher with the query 
        Dim searcher As ManagementObjectSearcher
        searcher = New ManagementObjectSearcher( _
            New SelectQuery("Win32_Service"))

        ' Create a results watcher object,  
        ' and handler for results and completion 
        Dim results As ManagementOperationObserver
        results = New ManagementOperationObserver

        ' Attach handler to events for 
        ' results and completion 
        AddHandler results.ObjectReady, _
            AddressOf Me.NewObject
        AddHandler results.Completed, _
            AddressOf Me.Done

        ' Call the asynchronous overload of 
        ' Get() to start the enumeration
        searcher.Get(results)

        ' Do something else while results  
        ' arrive(asynchronously)
        Do While (Me.Completed.Equals(False))

            System.Threading.Thread.Sleep(1000)
        Loop 

        Me.Reset()

    End Sub 

    Private isCompleted As Boolean 

    Private Sub NewObject(ByVal sender As Object, _
        ByVal e As ObjectReadyEventArgs)

        Console.WriteLine("Service : {0}, State = {1}", _
         e.NewObject("Name"), e.NewObject("State"))
    End Sub 

    Private ReadOnly Property Completed() As Boolean 
        Get 
            Return isCompleted
        End Get 
    End Property 

    Private Sub Reset()

        isCompleted = False 
    End Sub 

    Private Sub Done(ByVal sender As Object, _
        ByVal e As CompletedEventArgs)

        isCompleted = True 
    End Sub 


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

        Dim example As New EnumerateInstancesAsync

        Return 0

    End Function 

End Class

System.Object
  System.Management.ManagementOperationObserver

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 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

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