EventWatcherOptions 类

定义

命名空间:

System.Management

程序集:

System.Management.dll

包:

System.Management v8.0.0

Source:

ManagementOptions.cs

指定用于管理事件监视的选项。

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

public class EventWatcherOptions : System.Management.ManagementOptions

type EventWatcherOptions = class
    inherit ManagementOptions

Public Class EventWatcherOptions
Inherits ManagementOptions

继承

Object

ManagementOptions

EventWatcherOptions

示例

下面的示例演示由于事件类__InstanceCreationEvent而创建 Win32_Process 实例时，客户端如何接收通知。 有关详细信息，请参阅 Windows Management Instrumentation 文档。 客户端通过调用 WaitForNextEvent 方法来同步接收事件。 在运行此代码示例的同时，可以启动进程（如记事本）来测试此示例。

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

构造函数

EventWatcherOptions()	使用默认值为事件监视初始化 EventWatcherOptions 类的新实例。 这是无参数构造函数。
EventWatcherOptions(ManagementNamedValueCollection, TimeSpan, Int32)	使用给定的值初始化 EventWatcherOptions 类的新实例。

属性

BlockSize	获取或设置块操作的块大小。 等待事件时，此值指定返回前要等待多少事件。
Context	获取或设置一个 WMI 上下文对象。 这是将传递给 WMI 提供程序的名称-值对列表，该提供程序支持自定义操作的上下文信息。 (继承自 ManagementOptions)
Timeout	获取或设置要应用于该操作的超时。 注意，对于返回集合的操作，此超时将通过结果集合（而不是操作本身）应用于枚举（对于后面一种情况，应使用 ReturnImmediately 属性）。 此属性用来指示将以半同步方式执行操作。 (继承自 ManagementOptions)

方法

Clone()	返回对象的一个副本。
Equals(Object)	确定指定对象是否等于当前对象。 (继承自 Object)
GetHashCode()	作为默认哈希函数。 (继承自 Object)
GetType()	获取当前实例的 Type。 (继承自 Object)
MemberwiseClone()	创建当前 Object 的浅表副本。 (继承自 Object)
ToString()	返回表示当前对象的字符串。 (继承自 Object)