EventWatcherOptions 類別

定義

命名空間:

System.Management

組件:

System.Management.dll

指定管理事件監看的選項。

public ref class EventWatcherOptions : System::Management::ManagementOptions

public class EventWatcherOptions : System.Management.ManagementOptions

type EventWatcherOptions = class
    inherit ManagementOptions

Public Class EventWatcherOptions
Inherits ManagementOptions

繼承

Object

ManagementOptions

EventWatcherOptions

範例

下列範例顯示當建立 Win32_Process 實例時，用戶端如何接收通知，因為事件類別 __InstanceCreationEvent。 如需詳細資訊，請參閱Windows Management Instrumentation檔。 用戶端呼叫 WaitForNextEvent 方法，就可以同步接收事件。 在範例程式碼執行時，可以透過啟動處理序 (例如，[記事本]) 來測試這個範例。

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
        EventWatcherOptions eventOptions = new
            EventWatcherOptions();
        eventOptions.Timeout = System.TimeSpan.MaxValue;

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

        // 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
        Dim eventOptions As New EventWatcherOptions
        eventOptions.Timeout = System.TimeSpan.MaxValue

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

        ' 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

建構函式

EventWatcherOptions()	使用預設值，初始化 EventWatcherOptions 類別的新執行個體。 這是無參數建構函式。
EventWatcherOptions(ManagementNamedValueCollection, TimeSpan, Int32)	使用指定值，初始化 EventWatcherOptions 類別的新執行個體。

屬性

BlockSize	取得或設定區塊操作的區塊大小。 等待事件時，這個值可以指定在傳回前要等待多少事件。
Context	取得或設定 WMI 內容物件。 這是名稱值配對清單，將要傳送至 WMI 提供者 (Provider)，支援自訂作業的內容資訊。 (繼承來源 ManagementOptions)
Timeout	取得或設定套用至作業的逾時。 請注意，對於傳回集合的作業來說，這個逾時會經由產生的集合套用至列舉，而不是作業本身 (ReturnImmediately 屬性會為後者使用)。 這個屬性是用來指示作業應該半同步執行。 (繼承來源 ManagementOptions)

方法

Clone()	傳回物件的複本。
Equals(Object)	判斷指定的物件是否等於目前的物件。 (繼承來源 Object)
GetHashCode()	做為預設雜湊函式。 (繼承來源 Object)
GetType()	取得目前執行個體的 Type。 (繼承來源 Object)
MemberwiseClone()	建立目前 Object 的淺層複製。 (繼承來源 Object)
ToString()	傳回代表目前物件的字串。 (繼承來源 Object)