Dns.EndResolve(IAsyncResult) 方法

定义

注意

EndResolve is obsoleted for this type, please use EndGetHostEntry instead. https://go.microsoft.com/fwlink/?linkid=14202

注意

EndResolve has been deprecated. Use EndGetHostEntry instead.

注意

EndResolve is obsoleted for this type, please use EndGetHostEntry instead. http://go.microsoft.com/fwlink/?linkid=14202

结束对 DNS 信息的异步请求。

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

参数

asyncResult
IAsyncResult

一个 IAsyncResult 实例,该实例通过调用 BeginResolve(String, AsyncCallback, Object) 方法返回。

返回

一个 IPHostEntry 对象,该对象包含一个主机的 DNS 信息。

属性

例外

asyncResultnull

示例

以下示例结束对 DNS 主机信息的异步请求。

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
    End Class
    
    
    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
    
    
    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

注解

此方法将一直阻止,直到操作完成。

Ipv6Element.Enabled如果 设置为 true,则Aliases此方法不会填充返回的IPHostEntry实例的 属性,并且将始终为空。

若要同步执行此操作,请使用 Resolve 方法。

注意

在应用程序中启用网络跟踪时,此成员会发出跟踪信息。 有关详细信息,请参阅 .NET Framework 中的网络跟踪

适用于

另请参阅