Asynchronously returns the Internet Protocol (IP) addresses for the specified host.
Assembly: System (in System.dll)
[<HostProtectionAttribute(SecurityAction.LinkDemand, ExternalThreading = true)>] static member BeginGetHostAddresses : hostNameOrAddress:string * requestCallback:AsyncCallback * state:Object -> IAsyncResult
- Type: System.String
The host name or IP address to resolve.
- Type: System.AsyncCallback
An AsyncCallback delegate that references the method to invoke when the operation is complete.
- 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.
hostNameOrAddress is a null reference (Nothing in Visual Basic).
The length of hostNameOrAddress is greater than 255 characters.
An error is encountered when resolving hostNameOrAddress.
hostNameOrAddress is an invalid IP address.
The method asynchronously queries a DNS server for the IP addresses that are associated with a host name. If hostNameOrAddress is an IP address, this address is returned without querying the DNS server.
This member emits trace information when you enable network tracing in your application. For more information, see Network Tracing.
When an empty string is passed as the host name, this method returns the IPv4 addresses of the local host for all operating systems except Windows Server 2003; for Windows Server 2003, both IPv4 and IPv6 addresses for the local host are returned.
The asynchronous operation must be completed by calling the EndGetHostAddresses 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 GetHostAddresses method.
For more information about using the asynchronous programming model, see Calling Synchronous Methods Asynchronously
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.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.