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@zmilojko
Last active August 14, 2024 15:38
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C# sends and receives UDP broadcasts
using System;
using System.Net.Sockets;
using System.Net;
using System.Text;
using System.Threading;
namespace UDPer
{
class UDPer
{
const int PORT_NUMBER = 15000;
Thread t = null;
public void Start()
{
if (t != null)
{
throw new Exception("Already started, stop first");
}
Console.WriteLine("Started listening");
StartListening();
}
public void Stop()
{
try
{
udp.Close();
Console.WriteLine("Stopped listening");
}
catch { /* don't care */ }
}
private readonly UdpClient udp = new UdpClient(PORT_NUMBER);
IAsyncResult ar_ = null;
private void StartListening()
{
ar_ = udp.BeginReceive(Receive, new object());
}
private void Receive(IAsyncResult ar)
{
IPEndPoint ip = new IPEndPoint(IPAddress.Any, PORT_NUMBER);
byte[] bytes = udp.EndReceive(ar, ref ip);
string message = Encoding.ASCII.GetString(bytes);
Console.WriteLine("From {0} received: {1} ", ip.Address.ToString(), message);
StartListening();
}
public void Send(string message)
{
UdpClient client = new UdpClient();
IPEndPoint ip = new IPEndPoint(IPAddress.Parse("255.255.255.255"), PORT_NUMBER);
byte[] bytes = Encoding.ASCII.GetBytes(message);
client.Send(bytes, bytes.Length, ip);
client.Close();
Console.WriteLine("Sent: {0} ", message);
}
}
class Program
{
static void Main(string[] args)
{
UDPer udp = new UDPer();
udp.Start();
ConsoleKeyInfo cki;
do
{
if (Console.KeyAvailable)
{
cki = Console.ReadKey(true);
switch (cki.KeyChar)
{
case 's':
udp.Send(new Random().Next().ToString());
break;
case 'x':
udp.Stop();
return;
}
}
Thread.Sleep(10);
} while (true);
}
}
}
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