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ManagementEventWatcher 建構函式

定義

初始化 ManagementEventWatcher 類別的新執行個體。

多載

ManagementEventWatcher()

初始化 ManagementEventWatcher 類別的新執行個體。 如需進一步初始化,請設定物件上的屬性。 這是無參數建構函式。

ManagementEventWatcher(EventQuery)

當指定 WMI「事件查詢」時,初始化 ManagementEventWatcher 類別的新執行個體。

ManagementEventWatcher(String)

當以字串形式指定 WMI「事件查詢」時,初始化 ManagementEventWatcher 類別的新執行個體。

ManagementEventWatcher(ManagementScope, EventQuery)

初始化 ManagementEventWatcher 類別的新執行個體,此類別會接聽與指定的 WMI「事件查詢」相符的事件。

ManagementEventWatcher(String, String)

初始化 ManagementEventWatcher 類別的新執行個體,此類別會接聽與指定的 WMI「事件查詢」相符的事件。 這個變數的查詢和範圍會指定為字串。

ManagementEventWatcher(ManagementScope, EventQuery, EventWatcherOptions)

根據指定的選項,初始化 ManagementEventWatcher 類別 (會接聽與指定的 WMI 事件查詢相符的事件) 的新執行個體。 這個變數的查詢和範圍是指定的物件。 選項物件可以指定選項 (例如,逾時和內容資訊)。

ManagementEventWatcher(String, String, EventWatcherOptions)

根據指定的選項,初始化 類別的新實例 ManagementEventWatcher ,以接聽符合指定WMI 事件查詢的事件。 這個變數的查詢和範圍會指定為字串。 選項物件可以指定選項 (例如,逾時和內容資訊)。

ManagementEventWatcher()

來源:
ManagementEventWatcher.cs
來源:
ManagementEventWatcher.cs
來源:
ManagementEventWatcher.cs

初始化 ManagementEventWatcher 類別的新執行個體。 如需進一步初始化,請設定物件上的屬性。 這是無參數建構函式。

public:
 ManagementEventWatcher();
public ManagementEventWatcher ();
Public Sub New ()

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
        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

備註

.NET Framework 安全性

完全信任立即呼叫者。 這個成員無法供部分信任的程式碼使用。 如需詳細資訊,請參閱 使用部分信任程式代碼的連結庫

適用於

ManagementEventWatcher(EventQuery)

來源:
ManagementEventWatcher.cs
來源:
ManagementEventWatcher.cs
來源:
ManagementEventWatcher.cs

當指定 WMI「事件查詢」時,初始化 ManagementEventWatcher 類別的新執行個體。

public:
 ManagementEventWatcher(System::Management::EventQuery ^ query);
public ManagementEventWatcher (System.Management.EventQuery query);
new System.Management.ManagementEventWatcher : System.Management.EventQuery -> System.Management.ManagementEventWatcher
Public Sub New (query As EventQuery)

參數

query
EventQuery

EventQuery,表示會判斷監看員將接聽之事件的 WMI 事件查詢。

範例

在此程式代碼範例中,用戶端會在建立 Win32_Process 實例時收到通知,因為事件類別 是__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\"";

        // 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

備註

監看員要接聽事件的命名空間是目前設定的預設命名空間。

.NET Framework 安全性

完全信任立即呼叫者。 這個成員無法供部分信任的程式碼使用。 如需詳細資訊,請參閱 使用部分信任程式代碼的連結庫

適用於

ManagementEventWatcher(String)

來源:
ManagementEventWatcher.cs
來源:
ManagementEventWatcher.cs
來源:
ManagementEventWatcher.cs

當以字串形式指定 WMI「事件查詢」時,初始化 ManagementEventWatcher 類別的新執行個體。

public:
 ManagementEventWatcher(System::String ^ query);
public ManagementEventWatcher (string query);
new System.Management.ManagementEventWatcher : string -> System.Management.ManagementEventWatcher
Public Sub New (query As String)

參數

query
String

WMI 事件查詢,會定義監看員將接聽的事件。

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\"";

        // 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

備註

監看員要接聽事件的命名空間是目前設定的預設命名空間。

.NET Framework 安全性

完全信任立即呼叫者。 這個成員無法供部分信任的程式碼使用。 如需詳細資訊,請參閱 使用部分信任程式代碼的連結庫

適用於

ManagementEventWatcher(ManagementScope, EventQuery)

來源:
ManagementEventWatcher.cs
來源:
ManagementEventWatcher.cs
來源:
ManagementEventWatcher.cs

初始化 ManagementEventWatcher 類別的新執行個體,此類別會接聽與指定的 WMI「事件查詢」相符的事件。

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.ManagementEventWatcher
Public Sub New (scope As ManagementScope, query As EventQuery)

參數

scope
ManagementScope

ManagementScope,表示監看員將會在其中接聽事件的範圍 (命名空間)。

query
EventQuery

EventQuery,表示會判斷監看員將接聽之事件的 WMI 事件查詢。

範例

在此程式代碼範例中,用戶端會在建立 Win32_Process 實例時收到通知,因為事件類別 是__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\"";

        // 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

備註

.NET Framework 安全性

完全信任立即呼叫者。 這個成員無法供部分信任的程式碼使用。 如需詳細資訊,請參閱 使用部分信任程式代碼的連結庫

適用於

ManagementEventWatcher(String, String)

來源:
ManagementEventWatcher.cs
來源:
ManagementEventWatcher.cs
來源:
ManagementEventWatcher.cs

初始化 ManagementEventWatcher 類別的新執行個體,此類別會接聽與指定的 WMI「事件查詢」相符的事件。 這個變數的查詢和範圍會指定為字串。

public:
 ManagementEventWatcher(System::String ^ scope, System::String ^ query);
public ManagementEventWatcher (string scope, string query);
new System.Management.ManagementEventWatcher : string * string -> System.Management.ManagementEventWatcher
Public Sub New (scope As String, query As String)

參數

scope
String

監看員要在其中接聽事件的管理範圍 (命名空間)。

query
String

查詢,定義監看員將接聽的事件。

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\"";

        // 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

備註

.NET Framework 安全性

完全信任立即呼叫者。 這個成員無法供部分信任的程式碼使用。 如需詳細資訊,請參閱 使用部分信任程式代碼的連結庫

適用於

ManagementEventWatcher(ManagementScope, EventQuery, EventWatcherOptions)

來源:
ManagementEventWatcher.cs
來源:
ManagementEventWatcher.cs
來源:
ManagementEventWatcher.cs

根據指定的選項,初始化 ManagementEventWatcher 類別 (會接聽與指定的 WMI 事件查詢相符的事件) 的新執行個體。 這個變數的查詢和範圍是指定的物件。 選項物件可以指定選項 (例如,逾時和內容資訊)。

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.ManagementEventWatcher
Public Sub New (scope As ManagementScope, query As EventQuery, options As EventWatcherOptions)

參數

scope
ManagementScope

ManagementScope,表示監看員將會在其中接聽事件的範圍 (命名空間)。

query
EventQuery

EventQuery,表示會判斷監看員將接聽之事件的 WMI 事件查詢。

options
EventWatcherOptions

EventWatcherOptions,表示用來監看事件的額外選項。

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
        // 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

備註

.NET Framework 安全性

完全信任立即呼叫者。 這個成員無法供部分信任的程式碼使用。 如需詳細資訊,請參閱 使用部分信任程式代碼的連結庫

適用於

ManagementEventWatcher(String, String, EventWatcherOptions)

來源:
ManagementEventWatcher.cs
來源:
ManagementEventWatcher.cs
來源:
ManagementEventWatcher.cs

根據指定的選項,初始化 類別的新實例 ManagementEventWatcher ,以接聽符合指定WMI 事件查詢的事件。 這個變數的查詢和範圍會指定為字串。 選項物件可以指定選項 (例如,逾時和內容資訊)。

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.ManagementEventWatcher
Public Sub New (scope As String, query As String, options As EventWatcherOptions)

參數

scope
String

監看員要在其中接聽事件的管理範圍 (命名空間)。

query
String

查詢,定義監看員將接聽的事件。

options
EventWatcherOptions

EventWatcherOptions,表示用來監看事件的額外選項。

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
        // 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

備註

.NET Framework 安全性

完全信任立即呼叫者。 這個成員無法供部分信任的程式碼使用。 如需詳細資訊,請參閱 使用部分信任程式代碼的連結庫

適用於