来一段.net 6 Websocket 聊天功能代码，要详细的，实用的

当然，这里是一段使用.NET 6实现Websocket聊天功能的代码。这段代码实现了基本的聊天功能，包括用户连接、断开连接、发送消息等。

首先，我们需要在Startup.cs文件中添加WebSocket中间件：

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

    app.UseWebSockets();

    app.Use(async (context, next) =>
    {
        if (context.Request.Path == "/ws")
        {
            if (context.WebSockets.IsWebSocketRequest)
            {
                WebSocket webSocket = await context.WebSockets.AcceptWebSocketAsync();
                await ChatManager.AddWebSocketAsync(webSocket);
            }
            else
            {
                context.Response.StatusCode = 400;
            }
        }
        else
        {
            await next();
        }
    });

    // ...
}

然后，我们可以创建一个ChatManager类来管理聊天室的WebSocket连接和消息发送：

public class ChatManager
{
    private static readonly List<WebSocket> _webSockets = new List<WebSocket>();

    public static async Task AddWebSocketAsync(WebSocket webSocket)
    {
        _webSockets.Add(webSocket);

        try
        {
            await ReceiveAsync(webSocket);
        }
        catch
        {
            await RemoveWebSocketAsync(webSocket);
        }
    }

    public static async Task RemoveWebSocketAsync(WebSocket webSocket)
    {
        _webSockets.Remove(webSocket);
        await webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, "WebSocket closed", CancellationToken.None);
    }

    public static async Task SendAllAsync(string message)
    {
        var buffer = Encoding.UTF8.GetBytes(message);
        var tasks = new List<Task>();
        foreach (var webSocket in _webSockets)
        {
            if (webSocket.State == WebSocketState.Open)
            {
                tasks.Add(webSocket.SendAsync(new ArraySegment<byte>(buffer), WebSocketMessageType.Text, true, CancellationToken.None));
            }
        }

        await Task.WhenAll(tasks);
    }

    private static async Task ReceiveAsync(WebSocket webSocket)
    {
        var buffer = new byte[1024 * 4];
        while (webSocket.State == WebSocketState.Open)
        {
            var result = await webSocket.ReceiveAsync(new ArraySegment<byte>(buffer), CancellationToken.None);

            if (result.MessageType == WebSocketMessageType.Close)
            {
                await RemoveWebSocketAsync(webSocket);
            }
            else if (result.MessageType == WebSocketMessageType.Text)
            {
                var message = Encoding.UTF8.GetString(buffer, 0, result.Count);
                await SendAllAsync(message);
            }
        }
    }
}

最后，我们可以在客户端使用JavaScript来连接WebSocket和发送消息：

const webSocket = new WebSocket('ws://localhost:5000/ws');
webSocket.addEventListener('open', () => {
    console.log('WebSocket connected');
});
webSocket.addEventListener('message', event => {
    console.log(event.data);
});
document.querySelector('#send-btn').addEventListener('click', () => {
    const message = document.querySelector('#message-input').value;
    webSocket.send(message);
});

这样，我们就实现了一个基本的Websocket聊天功能。