ManagementEventWatcher 构造函数
定义
重要
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初始化 ManagementEventWatcher 类的新实例。
重载
| ManagementEventWatcher() |
初始化 ManagementEventWatcher 类的新实例。 若要进一步初始化，请设置对象的属性。 这是无参数构造函数。 |
| ManagementEventWatcher(EventQuery) |
在给定一个 WMI 事件查询的情况下，初始化 ManagementEventWatcher 类的新实例。 |
| ManagementEventWatcher(String) |
在给定一个字符串形式的 WMI 事件查询的情况下，初始化 ManagementEventWatcher 类的新实例。 |
| ManagementEventWatcher(ManagementScope, EventQuery) |
初始化 ManagementEventWatcher 类的新实例，它可侦听符合给定 WMI 事件查询的事件。 |
| ManagementEventWatcher(String, String) |
初始化 ManagementEventWatcher 类的新实例，它可侦听符合给定 WMI 事件查询的事件。 对于此变体，查询和范围被指定为字符串。 |
| ManagementEventWatcher(ManagementScope, EventQuery, EventWatcherOptions) |
初始化 ManagementEventWatcher 类的一个新实例，它将根据指定选项侦听符合给定 WMI 事件查询的事件。 对于此变体，查询和范围为指定的对象。 选项对象可指定超时和上下文信息等选项。 |
| ManagementEventWatcher(String, String, EventWatcherOptions) |
根据指定的选项，初始化 类的新实例 ManagementEventWatcher ，该类侦听符合给定 WMI 事件查询的事件。 对于此变体，查询和范围被指定为字符串。 选项对象可指定超时和上下文信息之类的选项。 |
ManagementEventWatcher()
- Source:
- ManagementEventWatcher.cs
- Source:
- ManagementEventWatcher.cs
- Source:
- ManagementEventWatcher.cs
初始化 ManagementEventWatcher 类的新实例。 若要进一步初始化，请设置对象的属性。 这是无参数构造函数。
public:
ManagementEventWatcher();public ManagementEventWatcher ();Public Sub New ()示例
以下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
WqlEventQuery query =
new WqlEventQuery("__InstanceCreationEvent",
new TimeSpan(0,0,1),
"TargetInstance isa \"Win32_Process\"");
// Initialize an event watcher and subscribe to events
// that match this query
ManagementEventWatcher watcher =
new ManagementEventWatcher();
watcher.Query = query;
// times out watcher.WaitForNextEvent in 5 seconds
watcher.Options.Timeout = new TimeSpan(0,0,5);
// 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 New WqlEventQuery( _
"__InstanceCreationEvent", _
New TimeSpan(0, 0, 1), _
"TargetInstance isa ""Win32_Process""")
' Initialize an event watcher and subscribe to events
' that match this query
Dim watcher As New ManagementEventWatcher
watcher.Query = query
' times watcher.WaitForNextEvent in 5 seconds
watcher.Options.Timeout = New TimeSpan(0, 0, 5)
' 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
注解
.NET Framework 安全性
对直接调用方的完全信任。 此成员不能由部分信任的代码使用。 有关详细信息，请参阅 使用部分受信任的代码中的库。
适用于
ManagementEventWatcher(EventQuery)
- Source:
- ManagementEventWatcher.cs
- Source:
- ManagementEventWatcher.cs
- Source:
- ManagementEventWatcher.cs
在给定一个 WMI 事件查询的情况下，初始化 ManagementEventWatcher 类的新实例。
public:
ManagementEventWatcher(System::Management::EventQuery ^ query);public ManagementEventWatcher (System.Management.EventQuery query);new System.Management.ManagementEventWatcher : System.Management.EventQuery -> System.Management.ManagementEventWatcherPublic Sub New (query As EventQuery)参数
- query
- EventQuery
EventQuery，它表示一个确定观察程序将侦听的事件的 WMI 事件查询。
示例
在此代码示例中，客户端在创建 Win32_Process 实例时收到通知，因为事件类__InstanceCreationEvent。 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\"";
// Initialize an event watcher and subscribe to events
// that match this query
ManagementEventWatcher watcher =
new ManagementEventWatcher(new EventQuery(query));
// times out watcher.WaitForNextEvent in 5 seconds
watcher.Options.Timeout = new TimeSpan(0,0,5);
// 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"""
' Initialize an event watcher and subscribe to events
' that match this query
Dim watcher As New ManagementEventWatcher(New EventQuery( _
query))
' times watcher.WaitForNextEvent in 5 seconds
watcher.Options.Timeout = New TimeSpan(0, 0, 5)
' 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
注解
观察程序将侦听事件的命名空间是当前设置的默认命名空间。
.NET Framework 安全性
对直接调用方的完全信任。 此成员不能由部分信任的代码使用。 有关详细信息，请参阅 使用部分受信任的代码中的库。
适用于
ManagementEventWatcher(String)
- Source:
- ManagementEventWatcher.cs
- Source:
- ManagementEventWatcher.cs
- Source:
- ManagementEventWatcher.cs
在给定一个字符串形式的 WMI 事件查询的情况下，初始化 ManagementEventWatcher 类的新实例。
public:
ManagementEventWatcher(System::String ^ query);public ManagementEventWatcher (string query);new System.Management.ManagementEventWatcher : string -> System.Management.ManagementEventWatcherPublic Sub New (query As String)参数
- query
- String
一个 WMI 事件查询，它定义观察程序将侦听的事件。
示例
以下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\"";
// Initialize an event watcher and subscribe to events
// that match this query
ManagementEventWatcher watcher =
new ManagementEventWatcher(query);
// times out watcher.WaitForNextEvent in 5 seconds
watcher.Options.Timeout = new TimeSpan(0,0,5);
// 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"""
' Initialize an event watcher and subscribe to events
' that match this query
Dim watcher As New ManagementEventWatcher(query)
' times watcher.WaitForNextEvent in 5 seconds
watcher.Options.Timeout = New TimeSpan(0, 0, 5)
' 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
注解
观察程序将侦听事件的命名空间是当前设置的默认命名空间。
.NET Framework 安全性
对直接调用方的完全信任。 此成员不能由部分信任的代码使用。 有关详细信息，请参阅 使用部分受信任的代码中的库。
适用于
ManagementEventWatcher(ManagementScope, EventQuery)
- Source:
- ManagementEventWatcher.cs
- Source:
- ManagementEventWatcher.cs
- Source:
- ManagementEventWatcher.cs
初始化 ManagementEventWatcher 类的新实例，它可侦听符合给定 WMI 事件查询的事件。
public:
ManagementEventWatcher(System::Management::ManagementScope ^ scope, System::Management::EventQuery ^ query);public ManagementEventWatcher (System.Management.ManagementScope scope, System.Management.EventQuery query);new System.Management.ManagementEventWatcher : System.Management.ManagementScope * System.Management.EventQuery -> System.Management.ManagementEventWatcherPublic Sub New (scope As ManagementScope, query As EventQuery)参数
- scope
- ManagementScope
ManagementScope，它表示观察程序将在其中侦听事件的范围（命名空间）。
- query
- EventQuery
EventQuery，它表示一个确定观察程序将侦听的事件的 WMI 事件查询。
示例
在此代码示例中，客户端在创建 Win32_Process 实例时收到通知，因为事件类__InstanceCreationEvent。 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\"";
// Initialize an event watcher and subscribe to events
// that match this query
ManagementEventWatcher watcher =
new ManagementEventWatcher(
new ManagementScope("root\\CIMV2"),
new EventQuery(query));
// times out watcher.WaitForNextEvent in 5 seconds
watcher.Options.Timeout = new TimeSpan(0,0,5);
// 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"""
' Initialize an event watcher and subscribe to events
' that match this query
Dim watcher As New ManagementEventWatcher( _
New ManagementScope("root\CIMV2"), _
New EventQuery(query))
' times watcher.WaitForNextEvent in 5 seconds
watcher.Options.Timeout = New TimeSpan(0, 0, 5)
' 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
注解
.NET Framework 安全性
对直接调用方的完全信任。 此成员不能由部分信任的代码使用。 有关详细信息，请参阅 使用部分受信任的代码中的库。
适用于
ManagementEventWatcher(String, String)
- Source:
- ManagementEventWatcher.cs
- Source:
- ManagementEventWatcher.cs
- Source:
- ManagementEventWatcher.cs
初始化 ManagementEventWatcher 类的新实例，它可侦听符合给定 WMI 事件查询的事件。 对于此变体，查询和范围被指定为字符串。
public:
ManagementEventWatcher(System::String ^ scope, System::String ^ query);public ManagementEventWatcher (string scope, string query);new System.Management.ManagementEventWatcher : string * string -> System.Management.ManagementEventWatcherPublic Sub New (scope As String, query As String)参数
- scope
- String
观察程序将在其中侦听事件的管理范围（命名空间）。
- query
- String
定义观察程序所要侦听的事件的查询。
示例
以下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\"";
// Initialize an event watcher and subscribe to events
// that match this query
ManagementEventWatcher watcher =
new ManagementEventWatcher("root\\CIMV2",
query);
// times out watcher.WaitForNextEvent in 5 seconds
watcher.Options.Timeout = new TimeSpan(0,0,5);
// 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"""
' Initialize an event watcher and subscribe to events
' that match this query
Dim watcher As New ManagementEventWatcher( _
"root\CIMV2", query)
' times watcher.WaitForNextEvent in 5 seconds
watcher.Options.Timeout = New TimeSpan(0, 0, 5)
' 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
注解
.NET Framework 安全性
对直接调用方的完全信任。 此成员不能由部分信任的代码使用。 有关详细信息，请参阅 使用部分受信任的代码中的库。
适用于
ManagementEventWatcher(ManagementScope, EventQuery, EventWatcherOptions)
- Source:
- ManagementEventWatcher.cs
- Source:
- ManagementEventWatcher.cs
- Source:
- ManagementEventWatcher.cs
初始化 ManagementEventWatcher 类的一个新实例，它将根据指定选项侦听符合给定 WMI 事件查询的事件。 对于此变体，查询和范围为指定的对象。 选项对象可指定超时和上下文信息等选项。
public:
ManagementEventWatcher(System::Management::ManagementScope ^ scope, System::Management::EventQuery ^ query, System::Management::EventWatcherOptions ^ options);public ManagementEventWatcher (System.Management.ManagementScope scope, System.Management.EventQuery query, System.Management.EventWatcherOptions options);new System.Management.ManagementEventWatcher : System.Management.ManagementScope * System.Management.EventQuery * System.Management.EventWatcherOptions -> System.Management.ManagementEventWatcherPublic Sub New (scope As ManagementScope, query As EventQuery, options As EventWatcherOptions)参数
- scope
- ManagementScope
ManagementScope，它表示观察程序将在其中侦听事件的范围（命名空间）。
- query
- EventQuery
EventQuery，它表示一个确定观察程序将侦听的事件的 WMI 事件查询。
- options
- EventWatcherOptions
EventWatcherOptions，它表示用于监视事件的其他选项。
示例
以下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
// blockSize = 1, so wait for 1 event to return
EventWatcherOptions options = new EventWatcherOptions(
null, TimeSpan.MaxValue, 1);
// Initialize an event watcher and subscribe to events
// that match this query
ManagementEventWatcher watcher =
new ManagementEventWatcher(
new ManagementScope("root\\CIMV2"),
new EventQuery(query), options);
// 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
' blockSize = 1, so wait for 1 event to return
Dim options As New EventWatcherOptions( _
Nothing, TimeSpan.MaxValue, 1)
' Initialize an event watcher and subscribe to events
' that match this query
Dim watcher As New ManagementEventWatcher( _
New ManagementScope("root\CIMV2"), _
New EventQuery(query), _
options)
' 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
注解
.NET Framework 安全性
对直接调用方的完全信任。 此成员不能由部分信任的代码使用。 有关详细信息，请参阅 使用部分受信任的代码中的库。
适用于
ManagementEventWatcher(String, String, EventWatcherOptions)
- Source:
- ManagementEventWatcher.cs
- Source:
- ManagementEventWatcher.cs
- Source:
- ManagementEventWatcher.cs
根据指定的选项，初始化 类的新实例，该实例 ManagementEventWatcher 侦听符合给定 WMI 事件查询的事件。 对于此变体，查询和范围被指定为字符串。 选项对象可指定超时和上下文信息之类的选项。
public:
ManagementEventWatcher(System::String ^ scope, System::String ^ query, System::Management::EventWatcherOptions ^ options);public ManagementEventWatcher (string scope, string query, System.Management.EventWatcherOptions options);new System.Management.ManagementEventWatcher : string * string * System.Management.EventWatcherOptions -> System.Management.ManagementEventWatcherPublic Sub New (scope As String, query As String, options As EventWatcherOptions)参数
- scope
- String
观察程序将在其中侦听事件的管理范围（命名空间）。
- query
- String
定义观察程序所要侦听的事件的查询。
- options
- EventWatcherOptions
EventWatcherOptions，它表示用于监视事件的其他选项。
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
// blockSize = 1, so wait for 1 event to return
EventWatcherOptions options = new EventWatcherOptions(
null, TimeSpan.MaxValue, 1);
// Initialize an event watcher and subscribe to events
// that match this query
ManagementEventWatcher watcher =
new ManagementEventWatcher(
new ManagementScope("root\\CIMV2"),
new EventQuery(query), options);
// 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
' blockSize = 1, so wait for 1 event to return
Dim options As New EventWatcherOptions( _
Nothing, TimeSpan.MaxValue, 1)
' Initialize an event watcher and subscribe to events
' that match this query
Dim watcher As New ManagementEventWatcher( _
"root\CIMV2", _
query, _
options)
' 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
注解
.NET Framework 安全性
对直接调用方的完全信任。 此成员不能由部分信任的代码使用。 有关详细信息，请参阅 使用部分受信任的代码中的库。
