Dns.EndResolve(IAsyncResult) Dns.EndResolve(IAsyncResult) Dns.EndResolve(IAsyncResult) Dns.EndResolve(IAsyncResult) Method

Definition

Warning

This API is now obsolete.

Ends an asynchronous request for DNS information.

public:
 static System::Net::IPHostEntry ^ EndResolve(IAsyncResult ^ asyncResult);
[System.Obsolete("Use EndGetHostEntry instead")]
[System.Obsolete("EndResolve is obsoleted for this type, please use EndGetHostEntry instead. http://go.microsoft.com/fwlink/?linkid=14202")]
[System.Obsolete("EndResolve is obsoleted for this type, please use EndGetHostEntry instead. https://go.microsoft.com/fwlink/?linkid=14202")]
public static System.Net.IPHostEntry EndResolve (IAsyncResult asyncResult);
static member EndResolve : IAsyncResult -> System.Net.IPHostEntry
Public Shared Function EndResolve (asyncResult As IAsyncResult) As IPHostEntry

Parameters

asyncResult
IAsyncResult IAsyncResult IAsyncResult IAsyncResult

An IAsyncResult instance that is returned by a call to the BeginResolve(String, AsyncCallback, Object) method.

Returns

An IPHostEntry object that contains DNS information about a host.

Exceptions

Examples

The following example ends an asynchronous request for DNS host information.

public ref class DnsBeginGetHostByName
{
public:
   static System::Threading::ManualResetEvent^ allDone = nullptr;
   ref class RequestState
   {
   public:
      IPHostEntry^ host;
      RequestState()
      {
         host = nullptr;
      }
   };

   static void RespCallback( IAsyncResult^ ar )
   {
      try
      {
         // Convert the IAsyncResult* Object* to a RequestState Object*.
         RequestState^ tempRequestState = dynamic_cast<RequestState^>(ar->AsyncState);
         
         // End the asynchronous request.
         tempRequestState->host = Dns::EndResolve( ar );
         allDone->Set();
      }
      catch ( ArgumentNullException^ e ) 
      {
         Console::WriteLine( "ArgumentNullException caught!!!" );
         Console::WriteLine( "Source : {0}", e->Source );
         Console::WriteLine( "Message : {0}", e->Message );
      }
      catch ( Exception^ e ) 
      {
         Console::WriteLine( "Exception caught!!!" );
         Console::WriteLine( "Source : {0}", e->Source );
         Console::WriteLine( "Message : {0}", e->Message );
      }
   }
};

int main()
{
   DnsBeginGetHostByName::allDone = gcnew ManualResetEvent( false );
   
   // Create an instance of the RequestState class.
   DnsBeginGetHostByName::RequestState^ myRequestState =
      gcnew DnsBeginGetHostByName::RequestState;
   
   // Begin an asynchronous request for information like host name, IP addresses, or
   // aliases for specified the specified URI.
   IAsyncResult^ asyncResult = Dns::BeginResolve( "www.contoso.com",
      gcnew AsyncCallback( DnsBeginGetHostByName::RespCallback ), myRequestState );
   
   // Wait until asynchronous call completes.
   DnsBeginGetHostByName::allDone->WaitOne();
   Console::WriteLine( "Host name : {0}", myRequestState->host->HostName );
   Console::WriteLine( "\nIP address list : " );
   for ( int index = 0; index < myRequestState->host->AddressList->Length; index++ )
      Console::WriteLine( myRequestState->host->AddressList[ index ] );
   Console::WriteLine( "\nAliases : " );
   for ( int index = 0; index < myRequestState->host->Aliases->Length; index++ )
      Console::WriteLine( myRequestState->host->Aliases[ index ] );
}
class DnsBeginGetHostByName
{   
   public static System.Threading.ManualResetEvent allDone = null;

   class RequestState
   {
      public IPHostEntry host;
      public RequestState()
      {
         host = null;
      }
   }

   public static void Main()
   {
     allDone = new ManualResetEvent(false);
     // Create an instance of the RequestState class.
     RequestState myRequestState = new RequestState();

     // Begin an asynchronous request for information like host name, IP addresses, or 
     // aliases for specified the specified URI.
     IAsyncResult asyncResult = Dns.BeginResolve("www.contoso.com", new AsyncCallback(RespCallback), myRequestState );

     // Wait until asynchronous call completes.
     allDone.WaitOne();
     Console.WriteLine("Host name : " + myRequestState.host.HostName);
     Console.WriteLine("\nIP address list : ");
     for(int index=0; index < myRequestState.host.AddressList.Length; index++)
     {
       Console.WriteLine(myRequestState.host.AddressList[index]);
     }      
     Console.WriteLine("\nAliases : ");
     for(int index=0; index < myRequestState.host.Aliases.Length; index++)
     {
       Console.WriteLine(myRequestState.host.Aliases[index]);
     }      
   }
   
   private static void RespCallback(IAsyncResult ar)
   {
     try 
     {
       // Convert the IAsyncResult object to a RequestState object.
       RequestState tempRequestState = (RequestState)ar.AsyncState;
       // End the asynchronous request.
       tempRequestState.host = Dns.EndResolve(ar);
       allDone.Set();
     }
	   catch(ArgumentNullException e) 
     {
       Console.WriteLine("ArgumentNullException caught!!!");
       Console.WriteLine("Source : " + e.Source);
       Console.WriteLine("Message : " + e.Message);
     }   
     catch(Exception e)
     {
       Console.WriteLine("Exception caught!!!");
       Console.WriteLine("Source : " + e.Source);
       Console.WriteLine("Message : " + e.Message);
     }
   }
}
Class DnsBeginGetHostByName
    
    Class RequestState
        Public host As IPHostEntry
        
        Public Sub New()
            host = Nothing
        End Sub 'New
    End Class 'RequestState
    
    
    Public Shared Sub Main()
     Try
        ' Create an instance of the RequestState class.
        Dim myRequestState As New RequestState()
        
        ' Begin an asynchronous request for information such as the host name, IP addresses, 
        ' or aliases for the specified URI.
        Dim asyncResult As IAsyncResult = CType(Dns.BeginResolve("www.contoso.com", AddressOf RespCallback, myRequestState),IAsyncResult)

        ' Wait until asynchronous call completes.
        While asyncResult.IsCompleted <> True
        End While
        
        Console.WriteLine(("Host name : " + myRequestState.host.HostName))
        Console.WriteLine(ControlChars.Cr + "IP address list : ")
        Dim index As Integer
        For index = 0 To myRequestState.host.AddressList.Length - 1
            Console.WriteLine(myRequestState.host.AddressList(index))
        Next index
        Console.WriteLine(ControlChars.Cr + "Aliases : ")

        For index = 0 To myRequestState.host.Aliases.Length - 1
            Console.WriteLine(myRequestState.host.Aliases(index))
        Next index
    catch e as Exception
            Console.WriteLine("Exception caught!!!")
            Console.WriteLine(("Source : " + e.Source))
            Console.WriteLine(("Message : " + e.Message))
    End Try
    End Sub 'Main
    
    
    Private Shared Sub RespCallback(ar As IAsyncResult)
        Try
            ' Convert the IAsyncResult object to a RequestState object.
            Dim tempRequestState As RequestState = CType(ar.AsyncState, RequestState)

            ' End the asynchronous request.
            tempRequestState.host = Dns.EndResolve(ar)
            Catch e As ArgumentNullException
            Console.WriteLine("ArgumentNullException caught!!!")
            Console.WriteLine(("Source : " + e.Source))
            Console.WriteLine(("Message : " + e.Message))
            Catch e As Exception
            Console.WriteLine("Exception caught!!!")
            Console.WriteLine(("Source : " + e.Source))
            Console.WriteLine(("Message : " + e.Message))
        End Try
    End Sub 'RespCallback

Remarks

This method blocks until the operation is complete.

If the Ipv6Element.Enabled is set to true, the Aliases property of the IPHostEntry instance returned is not populated by this method and will always be empty.

To perform this operation synchronously, use the Resolve method.

Note

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

Applies to

See also