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@darkguy2008
Last active November 11, 2024 19:54
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Simple C# UDP server/client in 56 lines
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
namespace UDP
{
public class UDPSocket
{
private Socket _socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
private const int bufSize = 8 * 1024;
private State state = new State();
private EndPoint epFrom = new IPEndPoint(IPAddress.Any, 0);
private AsyncCallback recv = null;
public class State
{
public byte[] buffer = new byte[bufSize];
}
public void Server(string address, int port)
{
_socket.SetSocketOption(SocketOptionLevel.IP, SocketOptionName.ReuseAddress, true);
_socket.Bind(new IPEndPoint(IPAddress.Parse(address), port));
Receive();
}
public void Client(string address, int port)
{
_socket.Connect(IPAddress.Parse(address), port);
Receive();
}
public void Send(string text)
{
byte[] data = Encoding.ASCII.GetBytes(text);
_socket.BeginSend(data, 0, data.Length, SocketFlags.None, (ar) =>
{
State so = (State)ar.AsyncState;
int bytes = _socket.EndSend(ar);
Console.WriteLine("SEND: {0}, {1}", bytes, text);
}, state);
}
private void Receive()
{
_socket.BeginReceiveFrom(state.buffer, 0, bufSize, SocketFlags.None, ref epFrom, recv = (ar) =>
{
State so = (State)ar.AsyncState;
int bytes = _socket.EndReceiveFrom(ar, ref epFrom);
_socket.BeginReceiveFrom(so.buffer, 0, bufSize, SocketFlags.None, ref epFrom, recv, so);
Console.WriteLine("RECV: {0}: {1}, {2}", epFrom.ToString(), bytes, Encoding.ASCII.GetString(so.buffer, 0, bytes));
}, state);
}
}
}
using System;
namespace UDP
{
class Program
{
static void Main(string[] args)
{
UDPSocket s = new UDPSocket();
s.Server("127.0.0.1", 27000);
UDPSocket c = new UDPSocket();
c.Client("127.0.0.1", 27000);
c.Send("TEST!");
Console.ReadKey();
}
}
}
@jenya7
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jenya7 commented Jun 29, 2021

s.Server("127.0.0.1", 27000);
It's a local IP or remote? What if I don't know a remote IP? I want to receive from any socket.

@MrAladross
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Thanks! I was looking for a good example of UDP and this is a nice starting point.

@Neox2018
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Neox2018 commented Apr 1, 2022

Is it suppose to work easily ? I'm new with that client/servers code.

@wisamidris7
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How to send a full file or image that sized 0.6mb or 600kb

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