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Dns.BeginGetHostByName Method

NOTE: This API is now obsolete.

Begins an asynchronous request for IPHostEntry information about the specified DNS host name.

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

'Declaration
<ObsoleteAttribute("BeginGetHostByName is obsoleted for this type, please use BeginGetHostEntry instead. http://go.microsoft.com/fwlink/?linkid=14202")> _
<HostProtectionAttribute(SecurityAction.LinkDemand, ExternalThreading := True)> _
Public Shared Function BeginGetHostByName ( _
	hostName As String, _
	requestCallback As AsyncCallback, _
	stateObject As Object _
) As IAsyncResult
'Usage
Dim hostName As String 
Dim requestCallback As AsyncCallback 
Dim stateObject As Object 
Dim returnValue As IAsyncResult 

returnValue = Dns.BeginGetHostByName(hostName, _
	requestCallback, stateObject)

Parameters

hostName
Type: System.String

The DNS name of the host.

requestCallback
Type: System.AsyncCallback

An AsyncCallback delegate that references the method to invoke when the operation is complete.

stateObject
Type: System.Object

A user-defined object that contains information about the operation. This object is passed to the requestCallback delegate when the operation is complete.

Return Value

Type: System.IAsyncResult
An IAsyncResult instance that references the asynchronous request.

ExceptionCondition
ArgumentNullException

hostName is Nothing.

SocketException

An error was encountered executing the DNS query.

NoteNote:

The HostProtectionAttribute attribute applied to this type or member has the following Resources property value: ExternalThreading. The HostProtectionAttribute does not affect desktop applications (which are typically started by double-clicking an icon, typing a command, or entering a URL in a browser). For more information, see the HostProtectionAttribute class or SQL Server Programming and Host Protection Attributes.

The asynchronous BeginGetHostByName operation must be completed by calling the EndGetHostByName method. Typically, the method is invoked by the requestCallback delegate.

This method does not block until the operation is complete. To block until the operation is complete, use the GetHostByName method.

For detailed information about using the asynchronous programming model, see Calling Synchronous Methods Asynchronously.

NoteNote:

This member emits trace information when you enable network tracing in your application. For more information, see Network Tracing.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC

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

.NET Framework

Supported in: 1.1, 1.0
Obsolete (compiler warning) in 3.5
Obsolete (compiler warning) in 3.5 SP1
Obsolete (compiler warning) in 3.0
Obsolete (compiler warning) in 3.0 SP1
Obsolete (compiler warning) in 3.0 SP2
Obsolete (compiler warning) in 2.0
Obsolete (compiler warning) in 2.0 SP1
Obsolete (compiler warning) in 2.0 SP2

.NET Compact Framework

Supported in: 1.0
Obsolete (compiler warning) in 3.5
Obsolete (compiler warning) in 2.0

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