AddressFamily Enumerazione

Definizione

public enum class AddressFamily

public enum AddressFamily

type AddressFamily = 

Public Enum AddressFamily

Ereditarietà

Object

ValueType

Enum

AddressFamily

Campi

Esempio

Nell'esempio seguente viene creato un Socket oggetto utilizzando InterNetwork AddressFamily.

using System;
using System.Text;
using System.IO;
using System.Net;
using System.Net.Sockets;

public class Sample
{

  public static string DoSocketGet(string server)
  {
    //Set up variables and String to write to the server.
    Encoding ASCII = Encoding.ASCII;
    string Get = "GET / HTTP/1.1\r\nHost: " + server +
                 "\r\nConnection: Close\r\n\r\n";
    Byte[] ByteGet = ASCII.GetBytes(Get);
    Byte[] RecvBytes = new Byte[256];
    String strRetPage = null;

    // IPAddress and IPEndPoint represent the endpoint that will
    //   receive the request.
    // Get first IPAddress in list return by DNS.

    try
    {

      // Define those variables to be evaluated in the next for loop and
      // then used to connect to the server. These variables are defined
      // outside the for loop to make them accessible there after.
      Socket s = null;
      IPEndPoint hostEndPoint;
      IPAddress hostAddress = null;
      int conPort = 80;

      // Get DNS host information.
      IPHostEntry hostInfo = Dns.GetHostEntry(server);
      // Get the DNS IP addresses associated with the host.
      IPAddress[] IPaddresses = hostInfo.AddressList;

      // Evaluate the socket and receiving host IPAddress and IPEndPoint.
      for (int index=0; index<IPaddresses.Length; index++)
      {
        hostAddress = IPaddresses[index];
        hostEndPoint = new IPEndPoint(hostAddress, conPort);


        // Creates the Socket to send data over a TCP connection.
        s = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp );


        // Connect to the host using its IPEndPoint.
        s.Connect(hostEndPoint);

        if (!s.Connected)
        {
          // Connection failed, try next IPaddress.
          strRetPage = "Unable to connect to host";
          s = null;
          continue;
        }

        // Sent the GET request to the host.
        s.Send(ByteGet, ByteGet.Length, 0);

      } // End of the for loop.


      // Receive the host home page content and loop until all the data is received.
      Int32 bytes = s.Receive(RecvBytes, RecvBytes.Length, 0);
      strRetPage = "Default HTML page on " + server + ":\r\n";
      strRetPage = strRetPage + ASCII.GetString(RecvBytes, 0, bytes);

      while (bytes > 0)
      {
        bytes = s.Receive(RecvBytes, RecvBytes.Length, 0);
        strRetPage = strRetPage + ASCII.GetString(RecvBytes, 0, bytes);
      }

    } // End of the try block.

    catch(SocketException e)
    {
      Console.WriteLine("SocketException caught!!!");
      Console.WriteLine("Source : " + e.Source);
      Console.WriteLine("Message : " + e.Message);
    }
    catch(ArgumentNullException e)
    {
      Console.WriteLine("ArgumentNullException caught!!!");
      Console.WriteLine("Source : " + e.Source);
      Console.WriteLine("Message : " + e.Message);
    }
    catch(NullReferenceException e)
    {
      Console.WriteLine("NullReferenceException 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);
    }

    return strRetPage;
}
   public static void Main()
   {
      Console.WriteLine(DoSocketGet("localhost"));
   }
 }

Imports System.Text
Imports System.IO
Imports System.Net
Imports System.Net.Sockets

 _

Public Class Sample
   
   
   Public Shared Function DoSocketGet(server As String) As String
      'Set up variables and String to write to the server.
    Dim ASCII As Encoding = Encoding.ASCII
    Dim [Get] As String = "GET / HTTP/1.1" + ControlChars.Lf + ControlChars.NewLine + "Host: " + server + ControlChars.Lf + ControlChars.NewLine + "Connection: Close" + ControlChars.Lf + ControlChars.NewLine + ControlChars.Lf + ControlChars.NewLine
    Dim ByteGet As [Byte]() = ASCII.GetBytes([Get])
    Dim RecvBytes(256) As [Byte]
    Dim strRetPage As [String] = Nothing


      
      ' IPAddress and IPEndPoint represent the endpoint that will
      '   receive the request.
      ' Get first IPAddress in list return by DNS.
      Try

 

         ' Define those variables to be evaluated in the next for loop and 
         ' then used to connect to the server. These variables are defined
         ' outside the for loop to make them accessible there after.
         Dim s As Socket = Nothing
         Dim hostEndPoint As IPEndPoint
         Dim hostAddress As IPAddress = Nothing
         Dim conPort As Integer = 80
         
         ' Get DNS host information.
         Dim hostInfo As IPHostEntry = Dns.Resolve(server)
         ' Get the DNS IP addresses associated with the host.
         Dim IPaddresses As IPAddress() = hostInfo.AddressList
         
         ' Evaluate the socket and receiving host IPAddress and IPEndPoint. 
      Dim index As Integer = 0
      For index = 0 To IPaddresses.Length - 1
        hostAddress = IPaddresses(index)
        hostEndPoint = New IPEndPoint(hostAddress, conPort)


        ' Creates the Socket to send data over a TCP connection.
        s = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)


        ' Connect to the host using its IPEndPoint.
        s.Connect(hostEndPoint)

        If Not s.Connected Then
          ' Connection failed, try next IPaddress.
          strRetPage = "Unable to connect to host"
          s = Nothing
          GoTo ContinueFor1
        End If


        ' Sent the GET request to the host.
        s.Send(ByteGet, ByteGet.Length, 0)


ContinueFor1:
      Next index  ' End of the for loop.
      



      ' Receive the host home page content and loop until all the data is received.

      'Dim bytes As Int32 = s.Receive(RecvBytes, RecvBytes.Length, 0)
      Dim bytes As Int32 = s.Receive(RecvBytes, RecvBytes.Length, 0)

      strRetPage = "Default HTML page on " + server + ":\r\n"
      strRetPage = "Default HTML page on " + server + ":" + ControlChars.Lf + ControlChars.NewLine

      Dim i As Integer

      While bytes > 0

        bytes = s.Receive(RecvBytes, RecvBytes.Length, 0)

        strRetPage = strRetPage + ASCII.GetString(RecvBytes, 0, bytes)

      End While


      ' End of the try block.
    Catch e As SocketException
         Console.WriteLine("SocketException caught!!!")
         Console.WriteLine(("Source : " + e.Source))
         Console.WriteLine(("Message : " + e.Message))
      Catch e As ArgumentNullException
         Console.WriteLine("ArgumentNullException caught!!!")
         Console.WriteLine(("Source : " + e.Source))
         Console.WriteLine(("Message : " + e.Message))
      Catch e As NullReferenceException
         Console.WriteLine("NullReferenceException 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
      
      Return strRetPage
   End Function 'DoSocketGet
    
   Public Shared Sub Main()
    Console.WriteLine(DoSocketGet("localhost"))
   End Sub
End Class

Commenti

Un AddressFamily membro specifica lo schema di indirizzamento che verrà utilizzato da un oggetto Socket per risolvere un indirizzo. Ad esempio, InterNetwork indica che è previsto un indirizzo IP versione 4 quando un oggetto Socket si connette a un endpoint.

Vedi anche

• IPAddress
• EndPoint