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)
[ObsoleteAttribute("BeginGetHostByName is obsoleted for this type, please use BeginGetHostEntry instead. http://go.microsoft.com/fwlink/?linkid=14202")] [HostProtectionAttribute(SecurityAction.LinkDemand, ExternalThreading = true)] public static IAsyncResult BeginGetHostByName( string hostName, AsyncCallback requestCallback, Object 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.IAsyncResultAn IAsyncResult instance that references the asynchronous request.
| Exception | Condition |
|---|---|
| ArgumentNullException | hostName is null. |
| SocketException | An error was encountered executing the DNS query. |
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.
 Note |
|---|
This member emits trace information when you enable network tracing in your application. For more information, see Network Tracing. |
| Note |
|---|
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. |
.NET Framework
Supported in: 1.1, 1.0Obsolete (compiler warning) in 4.5
Obsolete (compiler warning) in 4
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 Framework Client Profile
Obsolete (compiler warning) in 4Obsolete (compiler warning) in 3.5 SP1
- DnsPermission
for accessing DNS information. Associated enumeration: PermissionState.Unrestricted
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.
