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Class UdpClientAsyncExtensions

Provides extension methods for the UdpClient class to enable asynchronous operations.

Namespace

System.Net.Sockets

Assembly

System.Net.Sockets.dll

Syntax

public static class UdpClientAsyncExtensions

Methods

ReceiveAsync

Asynchronously receives a datagram from the UdpClient.

public static Task<UdpReceiveResult> ReceiveAsync(this UdpClient udpClient)

Parameters

Name Type Description
udpClient UdpClient The UdpClient instance to receive from.

Return Value

A Task<UdpReceiveResult> representing the asynchronous operation.

SendAsync

Asynchronously sends a datagram to a specified remote host.

public static Task<int> SendAsync(this UdpClient udpClient, byte[] datagram, int bytes, IPEndPoint endPoint)

Parameters

Name Type Description
udpClient UdpClient The UdpClient instance to send from.
datagram byte[] The data to send.
bytes int The number of bytes to send.
endPoint IPEndPoint The endpoint to send the datagram to.

Return Value

A Task<int> representing the asynchronous operation, with the number of bytes sent.

Remarks

The UdpClientAsyncExtensions class provides a convenient way to perform asynchronous network operations with UdpClient. These extension methods wrap the underlying asynchronous I/O operations, allowing you to write non-blocking code more easily.

Key methods include:

These methods are crucial for building responsive network applications, especially in scenarios involving user interfaces or high concurrency.

Example

Sending and Receiving Data Asynchronously

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

public class UdpExample
{
    public static async Task RunUdpClientAsync()
    {
        using var udpClient = new UdpClient(11000); // Listen on port 11000
        var remoteEndPoint = new IPEndPoint(IPAddress.Loopback, 11001);
        var dataToSend = Encoding.ASCII.GetBytes("Hello from UDP client!");

        // Send data
        int bytesSent = await udpClient.SendAsync(dataToSend, dataToSend.Length, remoteEndPoint);
        Console.WriteLine($"Sent {bytesSent} bytes.");

        // Receive data (simulated receiver on port 11001)
        var receiveTask = Task.Run(async () =>
        {
            using var receiverClient = new UdpClient(11001);
            Console.WriteLine("Receiver listening on port 11001...");
            var receivedResult = await receiverClient.ReceiveAsync();
            var receivedData = Encoding.ASCII.GetString(receivedResult.Buffer, 0, receivedResult.BytesTransferred);
            Console.WriteLine($"Received: {receivedData} from {receivedResult.RemoteEndPoint}");
        });

        await Task.Delay(new TimeSpan(0,0,1)); // Give receiver time to start
        await receiveTask;
    }
}