.net 6 websocket 搭建私聊群聊功能

要使用 .NET 6 搭建 WebSocket 私聊和群聊功能，可以按照以下步骤进行：

1. 创建 ASP.NET Core Web 应用程序，并在 Startup.cs 中配置 WebSocket 中间件。

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    // ...

    app.UseWebSockets();

    // ...
}

2. 创建一个 WebSocket 处理程序，并在其中实现消息处理逻辑。可以通过继承 `WebSocketHandler` 类来实现。

public class ChatWebSocketHandler : WebSocketHandler
{
    private readonly ConcurrentDictionary<string, WebSocket> _sockets = new();

    public ChatWebSocketHandler(WebSocketHandlerOptions options) : base(options)
    {
    }

    public override async Task OnConnectedAsync(WebSocket socket)
    {
        string socketId = GetSocketId(socket);

        _sockets.TryAdd(socketId, socket);

        await base.OnConnectedAsync(socket);
    }

    public override async Task OnDisconnectedAsync(WebSocket socket)
    {
        string socketId = GetSocketId(socket);

        _sockets.TryRemove(socketId, out WebSocket removedSocket);

        await base.OnDisconnectedAsync(socket);
    }

    public override async Task ReceiveAsync(WebSocket socket, WebSocketReceiveResult result, byte[] buffer)
    {
        string socketId = GetSocketId(socket);

        string message = Encoding.UTF8.GetString(buffer, 0, result.Count);

        // 处理消息逻辑

        await BroadcastAsync(socketId, message);
    }

    private async Task BroadcastAsync(string senderSocketId, string message)
    {
        foreach (KeyValuePair<string, WebSocket> socket in _sockets)
        {
            if (socket.Key != senderSocketId)
            {
                await SendMessageAsync(socket.Value, message);
            }
        }
    }

    private static async Task SendMessageAsync(WebSocket socket, string message)
    {
        byte[] buffer = Encoding.UTF8.GetBytes(message);

        await socket.SendAsync(new ArraySegment<byte>(buffer, 0, buffer.Length), WebSocketMessageType.Text, true, CancellationToken.None);
    }

    private static string GetSocketId(WebSocket socket)
    {
        return socket.GetHashCode().ToString();
    }
}

3. 在 Controller 中处理 WebSocket 连接请求，并将请求转发给 WebSocket 处理程序。

[Route("/ws")]
public class ChatController : Controller
{
    private readonly WebSocketHandler _webSocketHandler;

    public ChatController(WebSocketHandler webSocketHandler)
    {
        _webSocketHandler = webSocketHandler;
    }

    [HttpGet]
    public async Task Get()
    {
        if (HttpContext.WebSockets.IsWebSocketRequest)
        {
            WebSocket webSocket = await HttpContext.WebSockets.AcceptWebSocketAsync();

            await _webSocketHandler.OnConnectedAsync(webSocket);

            await _webSocketHandler.ReceiveAsync(webSocket, null, null);

            await _webSocketHandler.OnDisconnectedAsync(webSocket);
        }
        else
        {
            HttpContext.Response.StatusCode = 400;
        }
    }
}

4. 在 JavaScript 中建立 WebSocket 连接，并发送消息。

const webSocket = new WebSocket("ws://localhost:5000/ws");

webSocket.onmessage = function(event) {
    console.log(event.data);
};

webSocket.send("Hello, world!");

以上就是使用 .NET 6 搭建 WebSocket 私聊和群聊功能的基本步骤。具体实现细节可以根据实际需求进行调整。