Unity【Multiplayer 多人在线】- Socket 通用服务端框架（一）、定义套接字和多路复用

using System.Net;
using System.Net.Sockets;

namespace SK.Framework.Sockets
{
    /// <summary>
    /// 服务器
    /// </summary>
    public class Server
    {
        //定义套接字
        private static Socket socket;
        private static void Main(string[] args)
        {
            Init(8801);
        }
        //服务器初始化
        //port: 端口
        private static void Init(int port)
        {
            Console.WriteLine("服务器启动...");
            //TODO
        }
    }
}

using System.Net;
using System.Net.Sockets;

namespace SK.Framework.Sockets
{
    /// <summary>
    /// 服务器
    /// </summary>
    public class Server
    {
        //定义套接字
        private static Socket socket;
        private static void Main(string[] args)
        {
            Init(8801);
        }
        //服务器初始化
        //port: 端口
        private static void Init(int port)
        {
            Console.WriteLine("服务器启动...");
            //Socket Tcp协议
            socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            //服务器IP地址
            IPAddress ipAddress = IPAddress.Parse("0.0.0.0");
            IPEndPoint ipEndPoint = new IPEndPoint(ipAddress, port);
            //Bind
            socket.Bind(ipEndPoint);
            //Listen 开启监听
            socket.Listen(100);
            //TODO
        }
    }
}

Select多路复用：

// 摘要:
//     Determines the status of one or more sockets.
//
// 参数:
//   checkRead:
//     An System.Collections.IList of System.Net.Sockets.Socket instances to check for
//     readability.
//
//   checkWrite:
//     An System.Collections.IList of System.Net.Sockets.Socket instances to check for
//     writability.
//
//   checkError:
//     An System.Collections.IList of System.Net.Sockets.Socket instances to check for
//     errors.
//
//   microSeconds:
//     The time-out value, in microseconds. A -1 value indicates an infinite time-out.
//
// 异常:
//   T:System.ArgumentNullException:
//     The checkRead parameter is null or empty. -and- The checkWrite parameter is null
//     or empty -and- The checkError parameter is null or empty.
//
//   T:System.Net.Sockets.SocketException:
//     An error occurred when attempting to access the socket.
//
//   T:System.ObjectDisposedException:
//     .NET 5.0 and later: One or more sockets are disposed.
public static void Select(IList? checkRead, IList? checkWrite, IList? checkError, int microSeconds)

关于Select方法的官方文档链接地址：

using ProtoBuf;
using System.Net;
using System.Net.Sockets;

namespace SK.Framework.Sockets
{
    /// <summary>
    /// 服务器
    /// </summary>
    public class Server
    {
        //定义套接字
        private static Socket socket;
        //用于检测可读性的Socket列表
        private readonly static List<Socket> checkReadableList = new List<Socket>();
        //客户端Socket及客户端信息字典
        private readonly static Dictionary<Socket, Client> clients = new Dictionary<Socket, Client>();

        private static void Main(string[] args)
        {
            Init(8801);
        }
        //服务器初始化
        //port: 端口
        private static void Init(int port)
        {
            Console.WriteLine("服务器启动...");
            //Socket Tcp协议
            socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            //服务器IP地址
            IPAddress ipAddress = IPAddress.Parse("0.0.0.0");
            IPEndPoint ipEndPoint = new IPEndPoint(ipAddress, port);
            //Bind
            socket.Bind(ipEndPoint);
            //Listen 开启监听
            socket.Listen(0);

            //循环
            while (true)
            {
                //首先重置用于检测可读性的Socket列表
                OnCheckReadableListReset();
                //使用Select检测可读 实现non-block非阻塞方式
                //arg4: 超时值 单位毫秒 此处设置1000表示 1秒内没有可读消息时停止阻塞 返回空的列表
                Socket.Select(checkReadableList, null, null, 1000);
                //遍历检查可读对象
                for (int i = 0; i < checkReadableList.Count; i++)
                {
                    Socket s = checkReadableList[i];
                    if (s == socket) OnListenEvent(s);
                    else OnClientEvent(s);
                }
            }
        }
        private static void OnCheckReadableListReset()
        {
            checkReadableList.Clear();
            //进行Select的列表包含监听套接字socket以及每个已经连接的客户端套接字
            checkReadableList.Add(socket);
            foreach (Client client in clients.Values)
            {
                checkReadableList.Add(client.socket);
            }
        }
        //监听事件
        private static void OnListenEvent(Socket s) {}
        //客户端消息事件
        private static void OnClientEvent(Socket s) {}
    }
}

//监听事件
private static void OnListenEvent(Socket s)
{
    try
    {
        //接受客户端连接
        Socket socket = s.Accept();
        Console.WriteLine($"客户端接入: {socket.RemoteEndPoint}");
        Client client = new Client(socket);
        //加入字典
        clients.Add(socket, client);
    }
    catch (SocketException error)
    {
        Console.WriteLine($"客户端接入失败: {error}");
    }
}

OnClientEvent方法用于处理客户端发送来的消息，代码如下：

//客户端消息事件
private static void OnClientEvent(Socket s)
{
    //从字典中获取该客户端信息类
    Client client = clients[s];
    //该客户端的读缓冲区
    ByteArray readBuff = client.readBuff;
    //如果缓冲区剩余空间不足 清除
    if (readBuff.remain <= 0)
    {
        OnReceiveData(client);
        readBuff.MoveBytes();
    }
    //如果依然不足 接收数据失败 关闭客户端连接 返回
    //缓冲区默认大小为1024 根据最大单条数据长度进行调整
    if (readBuff.remain <= 0)
    {
        Console.WriteLine($"接收数据失败，超出缓冲区长度。{s.RemoteEndPoint}");
        //关闭客户端连接
        Close(client);
        return;
    }
    //接收数据长度
    int length = 0;
    try
    {
        length = s.Receive(readBuff.bytes, readBuff.writeIdx, readBuff.remain, 0);
    }
    catch (SocketException error)
    {
        Console.WriteLine($"接收数据失败: {error}. {s.RemoteEndPoint}");
        Close(client);
        return;
    }
    //客户端关闭
    if (length <= 0)
    {
        Close(client);
        return;
    }
    //处理数据
    readBuff.writeIdx += length;
    OnReceiveData(client);
    //移动缓冲区
    readBuff.CheckAndMoveBytes();
}
//数据处理
private static void OnReceiveData(Client client) {}