在C#中，你可以使用System.Net.WebSockets命名空间中的WebSocket类来创建一个WebSocket服务器。以下是一个简单的示例，展示了如何创建一个WebSocket服务器并在接收到客户端连接时发送消息：
using System; using System.Net.WebSockets; using System.Threading.Tasks; using Microsoft.AspNetCore.Http; namespace WebSocketServer { public class WebSocketHandler { private readonly WebSocket _webSocket; public WebSocketHandler(WebSocket webSocket) { _webSocket = webSocket; } public async Task OnConnectedAsync() { // 接收客户端发送的消息 var buffer = new byte[1024 * 4]; WebSocketReceiveResult result; do { result = await _webSocket.ReceiveAsync(new ArraySegment<byte>(buffer), CancellationToken.None); var message = Encoding.UTF8.GetString(buffer, 0, result.Count); Console.WriteLine($"Received message: {message}"); } while (!result.CloseStatus.HasValue); // 向客户端发送消息 var responseMessage = "Hello from WebSocket server!"; var responseBuffer = Encoding.UTF8.GetBytes(responseMessage); await _webSocket.SendAsync(new ArraySegment<byte>(responseBuffer), result.CloseStatus.Value, result.CloseStatusDescription, CancellationToken.None); } } public class Program { public static async Task Main(string[] args) { var builder = WebApplication.CreateBuilder(args); builder.Services.AddControllers(); builder.Services.AddEndpointsApiExplorer(); builder.Services.AddSwaggerGen(); var app = builder.Build(); app.UseHttpsRedirection(); app.UseAuthorization(); app.MapControllers(); // 注册WebSocket路由 app.Map("/ws", async (HttpContext context) => { if (context.WebSockets.IsWebSocketRequest) { var webSocket = await context.WebSockets.AcceptWebSocketAsync(); var webSocketHandler = new WebSocketHandler(webSocket); await webSocketHandler.OnConnectedAsync(); } else { context.Response.StatusCode = StatusCodes.Status400BadRequest; await context.Response.WriteAsync("This endpoint only supports WebSocket connections."); } }); app.Run(); } } } 在这个示例中，我们创建了一个简单的HTTP服务器，监听/ws路径上的WebSocket连接。当客户端连接到服务器时，OnConnectedAsync方法会被调用。在这个方法中，我们首先接收客户端发送的消息，然后向客户端发送一条响应消息。
