Udp Class

Visual Basic
C#
Managed Extensions for C++
C++/CLI

'Declaration
 
Public Class Udp 
   Inherits UdpBase

'Usage
 
Dim instance As Udp

public class Udp : UdpBase

public __gc class Udp : public UdpBase

public ref class Udp : public UdpBase

Use the Udp component to send and receive UDP datagrams.

Use the UdpBase.Open method to bind to a socket prior to sending and receiving.

Use the UdpBase.Send and UdpBase.Receive methods to send/receive datagrams.

Use UdpBase.JoinMulticastGroup to join a multicast group, and UdpBase.LeaveMulticastGroup to leave a multicast group.

Use Start to send or receive datagrams asynchronously, on a worker thread.

The following example demonstrates sending and receiving between two Udp components. The following example demonstrates joining a multicast group, sending data to it, receiving that data, and leaving the multicast group.

C#

private void buttonStartServer_Click(object sender, EventArgs e)
{
    //Start worker thread to bind to the socket and start echoing data.
    udpServer.Start(udpServer_Open, null);
}

private void buttonStopServer_Click(object sender, EventArgs e)
{ 
    udpServer.Close();
}

private void buttonDoEcho_Click(object sender, EventArgs e)
{
    //Start a Udp component to act as client
    udpClient.Start(udpClient_DoEcho, null);
}

private void udpServer_Open(object state)
{
    byte[] buffer = new byte[1024];
    udpServer.Open(7);
    Datagram datagram = udpServer.Receive(buffer);
    //Datagram is null when local socket has been closed
    while (datagram != null)
    {
        if (datagram.Count > 0)
            udpServer.Send(buffer, datagram.Origin);
        datagram = udpServer.Receive(buffer);
    }
}

private void udpClient_DoEcho(object state)
{
    //Send message, receive response and close
    byte[] buffer = new byte[1024];
    udpClient.Open(0);
    udpClient.Send("hello world!", "127.0.0.1", 7);
    Datagram datagram = udpClient.Receive(buffer);
    //marshal data to UI thread
    udpClient.Marshal(datagram.ToString(), null);
    udpClient.Close();
}

private void udpClient_UserState(object sender, UserStateEventArgs e)
{
    textBox1.AppendText(e.Message);
}

Visual Basic

Private Sub buttonStartServer_Click(ByVal sender As Object, ByVal e As EventArgs)
    'Start worker thread to bind to the socket and start echoing data.
    udpServer.Start(AddressOf udpServer_Open, Nothing)
End Sub

Private Sub buttonStopServer_Click(ByVal sender As Object, ByVal e As EventArgs)
    udpServer.Close()
End Sub

Private Sub buttonDoEcho_Click(ByVal sender As Object, ByVal e As EventArgs) Handles buttonDoEcho.Click
    'Start a Udp component to act as client
    udpClient.Start(AddressOf udpClient_DoEcho, Nothing)
End Sub

Private Sub udpServer_Open(ByVal state As Object)
    Dim buffer(1023) As Byte
    udpServer.Open(7)
    Dim datagram As Datagram = udpServer.Receive(buffer)
    'Datagram is null when local socket has been closed
    Do While datagram IsNot Nothing
        If datagram.Count > 0 Then
            udpServer.Send(buffer, datagram.Origin)
        End If
        datagram = udpServer.Receive(buffer)
    Loop
End Sub

Private Sub udpClient_DoEcho(ByVal state As Object)
    'Send message, receive response and close
    Dim buffer(1023) As Byte
    udpClient.Open(0)
    udpClient.Send("hello world!", "127.0.0.1", 7)
    Dim datagram As Datagram = udpClient.Receive(buffer)
    'marshal data to UI thread
    udpClient.Marshal(datagram.ToString(), Nothing)
    udpClient.Close()
End Sub

Private Sub udpClient_UserState(ByVal sender As Object, ByVal e As UserStateEventArgs)
    textBox1.AppendText(e.Message)
End Sub

C#

private void button1_Click(object sender, EventArgs e)
{
    udp1.Start(multicastWorker, null);
}

private void multicastWorker(object state)
{
    IPEndPoint groupEndPoint = new IPEndPoint("239.0.0.1", 32000);
    udp1.Open(32000);
    udp1.JoinMulticastGroup(groupEndPoint.Address);
    udp1.Send("hello world!", groupEndPoint);
    byte[] buffer = new byte[1024];
    Datagram datagram = udp1.Receive(buffer);
    //Marshal data to UI for display
    udp1.Marshal(datagram.ToString(), null);
    udp1.LeaveMulticastGroup(groupEndPoint.Address);
    udp1.Close();
}

void udp1_UserState(object sender, UserStateEventArgs e)
{
    textBox1.AppendText(e.Message);
}

Visual Basic

Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles button1.Click
    udp1.Start(AddressOf multicastWorker, Nothing)
End Sub

Private Sub multicastWorker(ByVal state As Object)
    Dim groupEndPoint As New IPEndPoint("239.0.0.1", 32000)
    udp1.Open(32000)
    udp1.JoinMulticastGroup(groupEndPoint.Address)
    udp1.Send("hello world!", groupEndPoint)
    Dim buffer(1023) As Byte
    Dim datagram As Datagram = udp1.Receive(buffer)
    'Marshal data to UI for display
    udp1.Marshal(datagram.ToString(), Nothing)
    udp1.LeaveMulticastGroup(groupEndPoint.Address)
    udp1.Close()
End Sub

Private Sub udp1_UserState(ByVal sender As Object, ByVal e As UserStateEventArgs)
    textBox1.AppendText(e.Message)
End Sub

System.Object
   System.MarshalByRefObject
      System.ComponentModel.Component
         Dart.Sockets.ComponentBase
            Dart.Sockets.SocketBase
               Dart.Sockets.UdpBase
                  Dart.Sockets.Udp

Reference

Udp Members
Dart.Sockets Namespace