MSDN Library

UdpClient.Receive Method

Receives a datagram from the UdpClient.

Parameters

Return Value

A byte array containing the data received.

Remarks

The Receive method blocks until a datagram is received. If you are using a connectionless socket, you must specify the sender's endpoint by calling ReceiveFrom or ReceiveFromAsync.

If the UdpClient is bound to a specific remote host using the Connect method, Receive will only return datagrams sent from that host.

The ReceiveAsync methods provide an asynchronous way to receive datagrams, allowing your application to remain responsive.

Example

The following code example demonstrates how to create a UDP client, bind it to a local port, and then receive data.

C#

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

public class UdpReceiver
{
    public static void Main(string[] args)
    {
        int port = 11000;
        UdpClient receiver = null;

        try
        {
            receiver = new UdpClient(port);
            Console.WriteLine($"UDP server listening on port {port}...");

            // Asynchronously receive data
            Task.Run(async () =>
            {
                while (true)
                {
                    try
                    {
                        UdpReceiveResult result = await receiver.ReceiveAsync();
                        string message = Encoding.ASCII.GetString(result.Buffer);
                        IPEndPoint remoteEP = result.RemoteEndPoint;

                        Console.WriteLine($"Received '{message}' from {remoteEP.Address}:{remoteEP.Port}");

                        // Example: Sending a confirmation back
                        byte[] confirmation = Encoding.ASCII.GetBytes("Message received.");
                        await receiver.SendAsync(confirmation, confirmation.Length, remoteEP);
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine($"Error receiving data: {ex.Message}");
                    }
                }
            });

            // Keep the main thread alive
            Console.WriteLine("Press any key to exit.");
            Console.ReadKey();
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Error starting UDP server: {ex.Message}");
        }
        finally
        {
            receiver?.Close();
        }
    }
}
            

Exceptions

Requirements