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PowerTCP SSL Sockets for .NET |
| Dart.PowerTCP.SslSockets Namespace > Udp Class : JoinMulticastGroup Method |
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PowerTCP SSL Sockets for .NET |
| Dart.PowerTCP.SslSockets Namespace > Udp Class : JoinMulticastGroup Method |
Join the specified multicast group for receiving datagrams.
[Visual Basic]
<DescriptionAttribute("Join the specified multicast group for receiving datagrams.")>
Public Sub JoinMulticastGroup( _
ByVal groupAddress As IPAddress _
) [C#]
[DescriptionAttribute("Join the specified multicast group for receiving datagrams.")]
public void JoinMulticastGroup(
IPAddress groupAddress
);[C++]
[DescriptionAttribute("Join the specified multicast group for receiving datagrams.")]
public: void JoinMulticastGroup(
IPAddress* groupAddress
) [C++/CLI]
[DescriptionAttribute("Join the specified multicast group for receiving datagrams.")]
public:
void JoinMulticastGroup(
IPAddress^ groupAddress
) | Exception | Description |
|---|---|
| SocketException | The multicast address is unknown, invalid, or unable to be resolved. |
Use the Udp.JoinMulticastGroup method to join a multicast group, useful when you wish for datagrams to be sent to multiple hosts. The host is able to receive all datagrams sent to the specified multicast address and port.
Multicast groups are specified as an IP Address within a specified range of addresses. This group of addresses, also know as class D IP Addresses, are in the range from 224.0.0.0 through 239.255.255.255. In order to receive packets sent to a multicast group (using Udp.Receive), you must first join the group using this method.
Using multicasting over broadcasting reduces the load on hosts that are not interested in the data sent.
The following example demonstrates using multicasting functionality to create a simple chat client.
[Visual Basic]
' The IPAddress representing the multicast address.
Private add As System.Net.IPAddress = System.Net.IPAddress.Parse("239.255.255.254")
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
' Allocate a socket for listening for datagrams.
Udp1.Open("MyHost", 1111)
' Join the specified multicast group.
Udp1.JoinMulticastGroup(add)
' Begin asynchronously receiving data
Dim buffer(Udp1.BufferSize) As Byte
Udp1.BeginReceive(buffer)
End Sub
Private Sub Udp1_EndReceive(ByVal sender As Object, ByVal e As DatagramEventArgs) Handles Udp1.EndReceive
' Data received. Display
txtData.Text += e.Datagram.ToString() + vbCrLF
' Begin asynchronously receiving data
Dim buffer(Udp1.BufferSize) As Byte
Udp1.BeginReceive(buffer)
End Sub
Private Sub cmdSend_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdSend.Click
' Send button clicked. Send the contents of txtSend.
Udp1.Send(txtSend.Text, add.ToString(), 1111)
End Sub
Private Sub cmdLeave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdLeave.Click
' Leave group button clicked. Leave the group.
Udp1.LeaveMulticastGroup(add)
End Sub
[C#]
// The IPAddress representing the multicast address.
private System.Net.IPAddress
add = System.Net.IPAddress.Parse("239.255.255.254");
private void Form1_Load(object sender, System.EventArgs e)
{
// Allocate a socket for listening for datagrams.
udp1.Open("MyHost", 1111);
// Join the specified multicast group.
udp1.JoinMulticastGroup(add);
// Begin asynchronously receiving data
byte[] buffer = new byte[udp1.BufferSize];
udp1.BeginReceive(buffer);
}
private void udp1_EndReceive(object
sender, DatagramEventArgs e)
{
// Data received. Display
txtData.Text += e.Datagram.ToString() + "\r\n";
// Begin asynchronously receiving data
byte[] buffer = new byte[udp1.BufferSize];
udp1.BeginReceive(buffer);
}
private void cmdSend_Click(object
sender, System.EventArgs e)
{
// Send button clicked. Send the contents of txtSend.
udp1.Send(txtSend.Text, add.ToString(), 1111);
}
private void cmdLeave_Click(object
sender, System.EventArgs e)
{
// Leave group button clicked. Leave the group.
udp1.LeaveMulticastGroup(add);
}
Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family
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Documentation version 1.1.2.0.
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