.net websocket demo

.NET WebSocket是一种在Web应用程序中实现双向通信的技术。它允许服务器和客户端之间进行实时的数据传输，而无需进行轮询或刷新页面。下面是一个简单的.NET WebSocket示例：

1. 创建WebSocket服务器：

using System;
using System.Net;
using System.Net.WebSockets;
using System.Threading;
using System.Threading.Tasks;

public class WebSocketServer
{
    private HttpListener _listener;
    private CancellationTokenSource _cancellationTokenSource;

    public async Task Start(string url)
    {
        _listener = new HttpListener();
        _listener.Prefixes.Add(url);
        _listener.Start();

        _cancellationTokenSource = new CancellationTokenSource();

        while (!_cancellationTokenSource.Token.IsCancellationRequested)
        {
            HttpListenerContext context = await _listener.GetContextAsync();
            if (context.Request.IsWebSocketRequest)
            {
                ProcessWebSocketRequest(context);
            }
            else
            {
                context.Response.StatusCode = 400;
                context.Response.Close();
            }
        }
    }

    private async void ProcessWebSocketRequest(HttpListenerContext context)
    {
        HttpListenerWebSocketContext webSocketContext = await context.AcceptWebSocketAsync(null);
        WebSocket webSocket = webSocketContext.WebSocket;

        byte[] buffer = new byte[1024];
        WebSocketReceiveResult result = await webSocket.ReceiveAsync(new ArraySegment<byte>(buffer), CancellationToken.None);

        while (!result.CloseStatus.HasValue)
        {
            string message = System.Text.Encoding.UTF8.GetString(buffer, 0, result.Count);
            Console.WriteLine($"Received message: {message}");

            // 处理接收到的消息

            result = await webSocket.ReceiveAsync(new ArraySegment<byte>(buffer), CancellationToken.None);
        }

        await webSocket.CloseAsync(result.CloseStatus.Value, result.CloseStatusDescription, CancellationToken.None);
    }

    public void Stop()
    {
        _cancellationTokenSource.Cancel();
        _listener.Stop();
        _listener.Close();
    }
}

2. 创建WebSocket客户端：

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

public class WebSocketClient
{
    private ClientWebSocket _webSocket;

    public async Task Connect(string url)
    {
        _webSocket = new ClientWebSocket();
        await _webSocket.ConnectAsync(new Uri(url), CancellationToken.None);

        await Task.WhenAll(ReceiveLoop(), SendLoop());
    }

    private async Task ReceiveLoop()
    {
        byte[] buffer = new byte[1024];

        while (_webSocket.State == WebSocketState.Open)
        {
            WebSocketReceiveResult result = await _webSocket.ReceiveAsync(new ArraySegment<byte>(buffer), CancellationToken.None);
            string message = Encoding.UTF8.GetString(buffer, 0, result.Count);
            Console.WriteLine($"Received message: {message}");
        }
    }

    private async Task SendLoop()
    {
        while (_webSocket.State == WebSocketState.Open)
        {
            string message = Console.ReadLine();
            byte[] buffer = Encoding.UTF8.GetBytes(message);
            await _webSocket.SendAsync(new ArraySegment<byte>(buffer), WebSocketMessageType.Text, true, CancellationToken.None);
        }
    }

    public async Task Disconnect()
    {
        await _webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, "Disconnect", CancellationToken.None);
        _webSocket.Dispose();
    }
}

3. 使用WebSocket服务器和客户端：

using System;
using System.Threading.Tasks;

public class Program
{
    public static async Task Main(string[] args)
    {
        string serverUrl = "http://localhost:8080/";
        string clientUrl = "ws://localhost:8080/";

        WebSocketServer server = new WebSocketServer();
        WebSocketClient client = new WebSocketClient();

        Task serverTask = server.Start(serverUrl);
        Task clientTask = client.Connect(clientUrl);

        await Task.WhenAll(serverTask, clientTask);

        server.Stop();
    }
}

这是一个简单的.NET WebSocket示例，它创建了一个WebSocket服务器和一个WebSocket客户端，并实现了基本的消息收发功能。你可以根据自己的需求进行扩展和修改。