C# UDP Socket 客户端和服务器

Question

我在这里的第一个问题。我是这种编程的新手，我只编写过 .NET 网站和表单。

现在，我工作的公司要求我制作一个 ActiveX 组件，它侦听 UDP 消息并将它们转换为事件。

UDP 消息是从 Avaya 系统发送的，所以我被告知要测试我的 ActiveX，首先我需要创建一个只发送 UDP 的应用程序（只有一个按钮发送预定义的 UDP 字符串）。然后创建侦听器套接字，普通的 C# 应用程序，它将从测试应用程序中获取那些传输的 UDP 字符串。两个应用都可以在同一台机器上运行。

稍后，当我得到这个工作时，我需要让监听器成为一个 ActiveX 组件，但首先要做的事情。

我想知道是否有关于这方面的好教程，以及关于如何开始的任何想法？我很抱歉我的无知，但我真的很陌生，我真的没有时间学习这个，因为它必须在 2 周内完成。

提前致谢。

编辑：我设法创建了 2 个简单的控制台应用程序，并且成功地在它们之间发送了 UDP 消息。发送方仅用于测试，现在我需要重新制作接收方以获取 UDP 消息并将其“翻译”为事件。最后，让它成为一个 ActiveX 控件...

Answer 1

简单的服务器和客户端：

public struct Received
{
    public IPEndPoint Sender;
    public string Message;
}

abstract class UdpBase
{
    protected UdpClient Client;

    protected UdpBase()
    {
        Client = new UdpClient();
    }

    public async Task<Received> Receive()
    {
        var result = await Client.ReceiveAsync();
        return new Received()
        {
            Message = Encoding.ASCII.GetString(result.Buffer, 0, result.Buffer.Length),
            Sender = result.RemoteEndPoint
        };
    }
}

//Server
class UdpListener : UdpBase
{
    private IPEndPoint _listenOn;

    public UdpListener() : this(new IPEndPoint(IPAddress.Any,32123))
    {
    }

    public UdpListener(IPEndPoint endpoint)
    {
        _listenOn = endpoint;
        Client = new UdpClient(_listenOn);
    }

    public void Reply(string message,IPEndPoint endpoint)
    {
        var datagram = Encoding.ASCII.GetBytes(message);
        Client.Send(datagram, datagram.Length,endpoint);
    }

}

//Client
class UdpUser : UdpBase
{
    private UdpUser(){}

    public static UdpUser ConnectTo(string hostname, int port)
    {
        var connection = new UdpUser();
        connection.Client.Connect(hostname, port);
        return connection;
    }

    public void Send(string message)
    {
        var datagram = Encoding.ASCII.GetBytes(message);
        Client.Send(datagram, datagram.Length);
    }

}

class Program 
{
    static void Main(string[] args)
    {
        //create a new server
        var server = new UdpListener();

        //start listening for messages and copy the messages back to the client
        Task.Factory.StartNew(async () => {
            while (true)
            {
                var received = await server.Receive();
                server.Reply("copy " + received.Message, received.Sender);
                if (received.Message == "quit")
                    break;
            }
        });

        //create a new client
        var client = UdpUser.ConnectTo("127.0.0.1", 32123);

        //wait for reply messages from server and send them to console 
        Task.Factory.StartNew(async () => {
            while (true)
            {
                try
                {
                    var received = await client.Receive();
                    Console.WriteLine(received.Message);
                    if (received.Message.Contains("quit"))
                        break;
                }
                catch (Exception ex)
                {
                    Debug.Write(ex);
                }
            }
        });

        //type ahead :-)
        string read;
        do
        {
            read = Console.ReadLine();
            client.Send(read);
        } while (read != "quit");
    }
}

Answer 2

简单的服务器和客户端：

using System;
using System.Text;
using System.Net;
using System.Net.Sockets;

class Program
{
    static void Main(string[] args)
    {
        // Create UDP client
        int receiverPort = 20000;
        UdpClient receiver = new UdpClient(receiverPort);

        // Display some information
        Console.WriteLine("Starting Upd receiving on port: " + receiverPort);
        Console.WriteLine("Press any key to quit.");
        Console.WriteLine("-------------------------------\n");

        // Start async receiving
        receiver.BeginReceive(DataReceived, receiver);

        // Send some test messages
        using (UdpClient sender1 = new UdpClient(19999))
            sender1.Send(Encoding.ASCII.GetBytes("Hi!"), 3, "localhost", receiverPort);
        using (UdpClient sender2 = new UdpClient(20001))
            sender2.Send(Encoding.ASCII.GetBytes("Hi!"), 3, "localhost", receiverPort);

        // Wait for any key to terminate application
        Console.ReadKey();
    }

    private static void DataReceived(IAsyncResult ar)
    {
        UdpClient c = (UdpClient)ar.AsyncState;
        IPEndPoint receivedIpEndPoint = new IPEndPoint(IPAddress.Any, 0);
        Byte[] receivedBytes = c.EndReceive(ar, ref receivedIpEndPoint);

        // Convert data to ASCII and print in console
        string receivedText = ASCIIEncoding.ASCII.GetString(receivedBytes);
        Console.Write(receivedIpEndPoint + ": " + receivedText + Environment.NewLine);

        // Restart listening for udp data packages
        c.BeginReceive(DataReceived, ar.AsyncState);
    }
}

Answer 3

服务器

public void serverThread()
{
    UdpClient udpClient = new UdpClient(8080);
    while(true)
    {
        IPEndPoint RemoteIpEndPoint = new IPEndPoint(IPAddress.Any, 0);
        Byte[] receiveBytes = udpClient.Receive(ref RemoteIpEndPoint);
        string returnData = Encoding.ASCII.GetString(receiveBytes);
        lbConnections.Items.Add(RemoteIpEndPoint.Address.ToString() 
                                + ":" +  returnData.ToString());
    }
}

并初始化线程

private void Form1_Load(object sender, System.EventArgs e)
{
    Thread thdUDPServer = new Thread(new ThreadStart(serverThread));
    thdUDPServer.Start();
}

客户

private void button1_Click(object sender, System.EventArgs e)
{
    UdpClient udpClient = new UdpClient();
    udpClient.Connect(txtbHost.Text, 8080);
    Byte[] senddata = Encoding.ASCII.GetBytes("Hello World");
    udpClient.Send(senddata, senddata.Length);
}

将其插入到按钮命令中。

来源：http://technotif.com/creating-simple-udp-server-client-transfer-data-using-c-vb-net/