UdpClient Classe

Definizione

public ref class UdpClient : IDisposable

public class UdpClient : IDisposable

type UdpClient = class
    interface IDisposable

Public Class UdpClient
Implements IDisposable

Ereditarietà

Object

UdpClient

Implementazioni

IDisposable

Esempio

Nell'esempio seguente viene stabilita una UdpClient connessione usando il nome www.contoso.com host sulla porta 11000. Un piccolo messaggio stringa viene inviato a due computer host remoti separati. Il Receive metodo blocca l'esecuzione fino a quando non viene ricevuto un messaggio. Usando l'oggetto IPEndPoint passato a Receive, viene rilevata l'identità dell'host che risponde.

// With this constructor the local port number is arbitrarily assigned.
UdpClient^ udpClient = gcnew UdpClient;
try
{
   udpClient->Connect( "host.contoso.com", 11000 );

   // Send message to the host to which you have connected.
   array<Byte>^sendBytes = Encoding::ASCII->GetBytes( "Is anybody there?" );
   udpClient->Send( sendBytes, sendBytes->Length );

   // Send message to a different host using optional hostname and port parameters.
   UdpClient^ udpClientB = gcnew UdpClient;
   udpClientB->Send( sendBytes, sendBytes->Length, "AlternateHostMachineName", 11000 );

   //IPEndPoint object will allow us to read datagrams sent from any source.
   IPEndPoint^ RemoteIpEndPoint = gcnew IPEndPoint( IPAddress::Any,0 );

   // Block until a message returns on this socket from a remote host.
   array<Byte>^receiveBytes = udpClient->Receive( RemoteIpEndPoint );
   String^ returnData = Encoding::ASCII->GetString( receiveBytes );

   // Use the IPEndPoint object to determine which of these two hosts responded.
   Console::WriteLine( String::Concat( "This is the message you received ", returnData->ToString() ) );
   Console::WriteLine( String::Concat( "This message was sent from ", RemoteIpEndPoint->Address->ToString(), " on their port number ", RemoteIpEndPoint->Port.ToString() ) );
   udpClient->Close();
   udpClientB->Close();
}
catch ( Exception^ e ) 
{
   Console::WriteLine( e->ToString() );
}

// This constructor arbitrarily assigns the local port number.
UdpClient udpClient = new UdpClient(11000);
    try{
         udpClient.Connect("www.contoso.com", 11000);

         // Sends a message to the host to which you have connected.
         Byte[] sendBytes = Encoding.ASCII.GetBytes("Is anybody there?");

         udpClient.Send(sendBytes, sendBytes.Length);

         // Sends a message to a different host using optional hostname and port parameters.
         UdpClient udpClientB = new UdpClient();
         udpClientB.Send(sendBytes, sendBytes.Length, "AlternateHostMachineName", 11000);

         //IPEndPoint object will allow us to read datagrams sent from any source.
         IPEndPoint RemoteIpEndPoint = new IPEndPoint(IPAddress.Any, 0);

         // Blocks until a message returns on this socket from a remote host.
         Byte[] receiveBytes = udpClient.Receive(ref RemoteIpEndPoint);
         string returnData = Encoding.ASCII.GetString(receiveBytes);

         // Uses the IPEndPoint object to determine which of these two hosts responded.
         Console.WriteLine("This is the message you received " +
                                      returnData.ToString());
         Console.WriteLine("This message was sent from " +
                                     RemoteIpEndPoint.Address.ToString() +
                                     " on their port number " +
                                     RemoteIpEndPoint.Port.ToString());

          udpClient.Close();
          udpClientB.Close();
          }
       catch (Exception e ) {
                  Console.WriteLine(e.ToString());
        }

     ' This constructor arbitrarily assigns the local port number.
     Dim udpClient As New UdpClient(11000)
     Try
        udpClient.Connect("www.contoso.com", 11000)
        
        ' Sends a message to the host to which you have connected.
        Dim sendBytes As [Byte]() = Encoding.ASCII.GetBytes("Is anybody there?")
        
        udpClient.Send(sendBytes, sendBytes.Length)
        
        ' Sends message to a different host using optional hostname and port parameters.
        Dim udpClientB As New UdpClient()
        udpClientB.Send(sendBytes, sendBytes.Length, "AlternateHostMachineName", 11000)
        
        ' IPEndPoint object will allow us to read datagrams sent from any source.
        Dim RemoteIpEndPoint As New IPEndPoint(IPAddress.Any, 0)
        
        ' UdpClient.Receive blocks until a message is received from a remote host.
        Dim receiveBytes As [Byte]() = udpClient.Receive(RemoteIpEndPoint)
        Dim returnData As String = Encoding.ASCII.GetString(receiveBytes)
        
        ' Which one of these two hosts responded?
        Console.WriteLine(("This is the message you received " + _
                                      returnData.ToString()))
         Console.WriteLine(("This message was sent from " + _
                                      RemoteIpEndPoint.Address.ToString() + _ 
                                      " on their port number " + _
                                      RemoteIpEndPoint.Port.ToString()))
        udpClient.Close()
        udpClientB.Close()

     Catch e As Exception
        Console.WriteLine(e.ToString())
     End Try
  End Sub

Commenti

La UdpClient classe fornisce metodi semplici per l'invio e la ricezione di datagrammi UDP senza connessione in modalità sincrona. Poiché UDP è un protocollo di trasporto senza connessione, non è necessario stabilire una connessione host remota prima di inviare e ricevere dati. È tuttavia possibile stabilire un host remoto predefinito in uno dei due modi seguenti:

• Create un'istanza della UdpClient classe usando il nome host remoto e il numero di porta come parametri.

• Create un'istanza della UdpClient classe e quindi chiamare il Connect metodo .

È possibile usare uno dei metodi di invio forniti in UdpClient per inviare dati a un dispositivo remoto. Usare il Receive metodo per ricevere dati da host remoti.

UdpClient i metodi consentono anche di inviare e ricevere datagrammi multicast. Usare il JoinMulticastGroup metodo per sottoscrivere un UdpClient gruppo multicast. Usare il metodo per annullare la DropMulticastGroupUdpClient sottoscrizione a un gruppo multicast.

Costruttori

Proprietà

Metodi

Implementazioni dell'interfaccia esplicita

Si applica a

Vedi anche

• TcpClient
• TCP-UDP