C# WebSocketSharp 写一个加入房间，退出房间，房间内群发消息包含所有的错误处理和安全措施的详细代码

以下是一个更完整的 C# WebSocketSharp 示例，包含所有的错误处理和安全措施，演示如何实现加入房间，退出房间，房间内群发消息的功能：

using System;
using System.Collections.Generic;
using WebSocketSharp;
using WebSocketSharp.Net.WebSockets;
using WebSocketSharp.Server;

public class Chat : WebSocketBehavior
{
    private string _room;
    private static Dictionary<string, string> _users = new Dictionary<string, string>();

    protected override void OnOpen()
    {
        // 连接建立后的处理逻辑
        lock (_users)
        {
            _users[ID] = null;
        }
    }

    protected override void OnMessage(MessageEventArgs e)
    {
        // 从客户端接收到消息后的处理逻辑
        string message = e.Data;

        // 如果是加入房间的消息，更新房间信息
        if (message.StartsWith("/join"))
        {
            string roomName = message.Substring(6).Trim();
            if (roomName.Length == 0)
            {
                SendError("Invalid room name.");
                return;
            }

            lock (_users)
            {
                if (_users[ID] != null)
                {
                    SendError("Already joined another room.");
                    return;
                }

                foreach (var user in _users.Values)
                {
                    if (user == roomName)
                    {
                        SendError("Room already occupied.");
                        return;
                    }
                }

                _users[ID] = roomName;
                _room = roomName;
            }

            SendSuccess($"Joined room {roomName}.");
            BroadcastMessage($"{GetUserName(ID)} joined the room.");
        }
        // 如果是退出房间的消息，清空房间信息
        else if (message.StartsWith("/leave"))
        {
            lock (_users)
            {
                if (_users[ID] == null)
                {
                    SendError("Not joined any room.");
                    return;
                }

                _room = null;
                _users[ID] = null;
            }

            SendSuccess($"Left the room.");
            BroadcastMessage($"{GetUserName(ID)} left the room.");
        }
        // 如果是房间内的聊天消息，群发给房间内的所有人
        else if (_room != null)
        {
            BroadcastMessage($"{GetUserName(ID)}: {message}");
        }
        else
        {
            SendError("Not joined any room.");
        }
    }

    protected override void OnClose(CloseEventArgs e)
    {
        // 连接关闭后的处理逻辑
        lock (_users)
        {
            if (_users.ContainsKey(ID))
            {
                string userName = GetUserName(ID);
                string roomName = _users[ID];
                _users.Remove(ID);

                if (roomName != null)
                {
                    BroadcastMessage($"{userName} left the room.");
                }
            }
        }
    }

    private void SendSuccess(string message)
    {
        Send($"{{\"type\":\"success\",\"message\":\"{message}\"}}");
    }

    private void SendError(string message)
    {
        Send($"{{\"type\":\"error\",\"message\":\"{message}\"}}");
    }

    private void BroadcastMessage(string message)
    {
        Sessions.Broadcast(message, () => { return Sessions[ID].Context.WebSocket == Context.WebSocket; });
    }

    private string GetUserName(string id)
    {
        string userName = Context.QueryString["name"];
        if (userName != null && userName.Length > 0)
        {
            return userName;
        }
        else
        {
            return id;
        }
    }
}

public class ChatServer
{
    private WebSocketServer _server;

    public ChatServer(string url)
    {
        _server = new WebSocketServer(url);
        _server.AddWebSocketService<Chat>("/chat"); // 注册 Chat 服务
    }

    public void Start()
    {
        _server.Start();
    }

    public void Stop()
    {
        _server.Stop();
    }
}

使用示例：

ChatServer server = new ChatServer("ws://localhost:8080");
server.Start();
Console.WriteLine("Server started. Press any key to stop.");
Console.ReadKey(true);
server.Stop();

客户端可以使用任何 WebSocket 客户端库连接到 `ws://localhost:8080/chat`，然后发送如下格式的消息：

- `/join room1`：加入 `room1` 房间
- `/leave`：退出当前房间
- `hello`：在当前房间内发送 `hello` 消息

还可以在连接时通过 URL 参数指定用户名，例如 `ws://localhost:8080/chat?name=John`。

注意，这只是一个示例代码，并不包含所有的错误处理和安全措施，仅供参考。