Dart.PowerTCP.SslSockets Namespace > Udp Class > Send Method : Send(Byte[],IPEndPoint) Method |
Send a datagram to the specified IPEndPoint.
[Visual Basic]
<DescriptionAttribute("Send a datagram from your buffer.")>
Overloads Public Function Send( _
ByVal buffer() As Byte, _
ByVal host As IPEndPoint _
) As Datagram
[C#]
[DescriptionAttribute("Send a datagram from your buffer.")]
public Datagram Send(
byte[] buffer,
IPEndPoint host
);
[C++]
[DescriptionAttribute("Send a datagram from your buffer.")]
public: Datagram* Send(
byte[]* buffer,
IPEndPoint* host
)
[C++/CLI]
[DescriptionAttribute("Send a datagram from your buffer.")]
public:
Datagram^ Send(
bytearray<buffer>^ buffer,
IPEndPoint^ host
)
A Datagram object encapsulating the datagram sent.
Exception | Description |
---|---|
ArgumentNullException | buffer is null. |
SocketException | The remote address is unknown, invalid, or unable to be resolved. |
ArgumentOutOfRangeException | The remote port is out of the range of valid values. |
Use the Udp.Send method to sent a datagram created from the data contained in buffer to the specified host.
A UDP datagram provides little functionality over an IP datagram, adding a port number field which allows multiplexing on the receiving host and checksum field which provides basic error handling. Unlike TCP, UDP datagrams are sent as a unit. If Udp.Send is called 3 times to send 3 datagrams to a host, the receiving host will have to call Receive 3 times. Also, the size of each datagram sent will equal the size of each datagram received by the receiving host. In addition, since UDP is a connectionless protocol, any datagrams sent to the host are not guaranteed to be delivered. Therefore, any required error checking (outside of UDP's checksum implementation) will have to be done by the application-layer protocol.
To send a broadcast datagram, use "255.255.255.255" as the remote address. To sent a multicast datagram, use the multicast group address as the remote address after first joining a multicast group by using Udp.JoinMulitcastGroup.
The following example demonstrates creating a UDP echo server application which listens for datagrams and echoes them back to the sender.
[Visual Basic]
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
' Listen for datagrams on port 7.
Udp1.Open(7)
' Begin an asynchronous Receive
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
' Check for an Exception
If e.Exception is Nothing Then
' Echo the data back using the Datagram object passed into the event.
' Datagram.Buffer = data received from client
' Datagram.RemoteEndPoint = address/port of client.
Udp1.Send(e.Datagram.Buffer, e.Datagram.RemoteEndPoint)
End If
' Start receiving next
Dim buffer(Udp1.BufferSize) As Byte
Udp1.BeginReceive(buffer)
End Sub
[C#]
private void StartServer()
{
// Listen for datagrams on port 7.
udp1.Open(7);
// Begin an asynchronous Receive
byte[] buffer = new byte[udp1.BufferSize];
udp1.BeginReceive(buffer);
}
private void udp1_EndReceive(object
sender, DatagramEventArgs e)
{
// Check for an exception
if(e.Exception == null)
{
// Echo the data back using the Datagram object passed into the event.
// Datagram.Buffer = data received from client
// Datagram.RemoteEndPoint = address/port of client.
Datagram d = udp1.Send(e.Datagram.Buffer, e.Datagram.RemoteEndPoint);
}
// Start receiving next
byte[] buffer = new byte[udp1.BufferSize];
udp1.BeginReceive(buffer);
}
Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family
Udp Class | Udp Members | Overload List
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Documentation version 1.1.2.0.
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