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NetworkChange Class

Allows applications to receive notification when the Internet Protocol (IP) address of a network interface, also called a network card or adapter, changes.

System.Object
  System.Net.NetworkInformation.NetworkChange

Namespace:  System.Net.NetworkInformation
Assembly:  System (in System.dll)

'Declaration
Public Class NetworkChange

The NetworkChange type exposes the following members.

  NameDescription
Public methodNetworkChange Obsolete. Initializes a new instance of the NetworkChange class.
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  NameDescription
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeServes as the default hash function. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodStatic memberRegisterNetworkChange Obsolete. Registers a network change instance to receive network change events.
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
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  NameDescription
Public eventStatic memberSupported by Portable Class LibrarySupported in .NET for Windows Store appsNetworkAddressChangedOccurs when the IP address of a network interface changes.
Public eventStatic memberNetworkAvailabilityChangedOccurs when the availability of the network changes.
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The NetworkChange class provides address change notification by raising NetworkAddressChanged events. An interface address can change for many reasons, such as a disconnected network cable, moving out of range of a wireless Local Area Network, or hardware failure.

To receive notification, you must identify your application's event handlers, which are one or more methods that perform your application-specific tasks each time the event is raised. To have a NetworkChange object call your event-handling methods when a NetworkAddressChanged event occurs, you must associate the methods with a NetworkAddressChangedEventHandler delegate, and add this delegate to the event.

The following code example listens for address changes and displays the status of network interfaces when a NetworkAddressChanged event occurs.

Imports System
Imports System.Net
Imports System.Net.NetworkInformation

Public Class NetworkingExample
    Public Shared Sub Main()
        AddHandler NetworkChange.NetworkAddressChanged, AddressOf AddressChangedCallback
        Console.WriteLine("Listening for address changes. Press any key to exit.")
        Console.ReadLine()
    End Sub 'Main
    Private Shared Sub AddressChangedCallback(ByVal sender As Object, ByVal e As EventArgs)

        Dim adapters As NetworkInterface() = NetworkInterface.GetAllNetworkInterfaces()
        Dim n As NetworkInterface
        For Each n In adapters
            Console.WriteLine("   {0} is {1}", n.Name, n.OperationalStatus)
        Next n
    End Sub 
End Class

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone 8, Silverlight 8.1

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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