ManagementOperationObserver.ObjectReady 事件

定义

新对象可用时发生。Occurs when a new object is available.

public:
 event System::Management::ObjectReadyEventHandler ^ ObjectReady;
public event System.Management.ObjectReadyEventHandler ObjectReady;
member this.ObjectReady : System.Management.ObjectReadyEventHandler 
Public Event ObjectReady As ObjectReadyEventHandler 

示例

下面的示例演示如何执行异步实例枚举。The following example demonstrates how to perform an asynchronous instance enumeration. 该示例使用 ManagementOperationObserver 类异步处理管理信息和事件。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
            SelectQuery("Win32_Service")); 

        // Create a results watcher object,
        // and handler for results and completion
        ManagementOperationObserver results = new
            ManagementOperationObserver();
        
        // Attach handler to events for results and completion
        results.ObjectReady += new 
            ObjectReadyEventHandler(this.NewObject);
        results.Completed += new 
            CompletedEventHandler(this.Done);

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

    private bool isCompleted = false;

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

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

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

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

        return;
    }
}
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

注解

事件数据Event Data

事件处理程序接收 ObjectReadyEventArgs 类型的参数,该参数包含与此事件相关的数据。The event handler receives an argument of type ObjectReadyEventArgs containing data related to this event. 以下 ObjectReadyEventArgs 属性提供特定于此事件的信息。The following ObjectReadyEventArgs properties provide information specific to this event.

属性Property 说明Description
Context (继承自 ManagementEventArgsContext (inherited from ManagementEventArgs) 获取从触发事件的操作反射回的操作上下文。Gets the operation context echoed back from the operation that triggered the event.
NewObject 获取新返回的对象。Gets the newly-returned object.

.NET Framework 安全性.NET Framework Security

对直接调用方的完全信任。Full trust for the immediate caller. 部分信任的程式碼無法使用此成員。This member cannot be used by partially trusted code. 有关详细信息,请参阅从部分受信任的代码使用库For more information, see Using Libraries from Partially Trusted Code.

适用于