Multi Tcp server 只能处理一个连接答案

【问题标题】：Multi Tcp server can only handle one connectionMulti Tcp server 只能处理一个连接
【发布时间】：2018-07-02 09:22:50
【问题描述】：

我正在开发一个可以处理许多客户端的 tcp 服务器。它是用 c# 异步和回调编写的。所以我完成了，但服务器只能处理一个连接...... Somewehre 包含一个错误，但经过 3 天的搜索，我不知道在哪里。我将粘贴代码。搞笑：客户端不会抛出任何错误。服务器只显示一个连接的客户端。其他客户端无法连接。

public class StateObject
{
    public Socket WorkSocket;
    public const int BufferSize = 32;
    public byte[] Buffer = new byte[BufferSize];
    public StringBuilder Sb = new StringBuilder();
}

internal class TcpServer
{
    public static Socket ServerSocket;
    public static List<SimClient> LbConnections = new List<SimClient>();

    public static async void StartTcpServerAsync()
    {
        try
        {
            await Task.Run(() =>
            {
                ServerSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                LbConnections = new List<SimClient>();
                var serverIp = new IPEndPoint(IPAddress.Parse(Settings.Default.IPAddress), Settings.Default.Port);

                ServerSocket.Bind(serverIp);
                ServerSocket.Listen(0);
                InitServer.IsServerReady = true;

                ServerSocket.BeginAccept(AcceptCallback, ServerSocket);
            });
        }
        catch (Exception e)
        {
            AdvancedLogging.WriteLog(e.Message + "(" + e.InnerException + ")", 2);
            InitServer.IsServerReady = false;
        }
    }

    private static void AcceptCallback(IAsyncResult result)
    {
        var listener = (Socket)result.AsyncState;
        var handler = listener.EndAccept(result);

        var state = new StateObject();
        state.WorkSocket = handler;

        LbConnections.Add(new SimClient { State = state });
        handler.BeginReceive(state.Buffer, 0, StateObject.BufferSize, SocketFlags.None, ReceiveCallback, state);
    }

    private static void ReceiveCallback(IAsyncResult result)
    {
        var state = (StateObject)result.AsyncState;
        var socket = state.WorkSocket;
        var received = socket.EndReceive(result);

        if (received <= 0)
        {
            socket.BeginReceive(state.Buffer, 0, StateObject.BufferSize, SocketFlags.None, ReceiveCallback, state);
            return;
        }

        state.Sb.Append(Encoding.ASCII.GetString(
            state.Buffer, 0, received));

        var content = state.Sb.ToString();
        if (content.IndexOf("<EOF>", StringComparison.Ordinal) > -1)
        {
            DataHandler.HandleData(content.Substring(0, content.Length - 5), state);
            state.Sb.Clear();
            socket.BeginReceive(state.Buffer, 0, StateObject.BufferSize, SocketFlags.None, ReceiveCallback, state);
        }
        else
        {
            socket.BeginReceive(state.Buffer, 0, StateObject.BufferSize, SocketFlags.None, ReceiveCallback, state);
        }
    }
}

【问题讨论】：

标签： c# sockets tcp server connection

【解决方案1】：

拨打handler.BeginReceive后需要拨打BeginAccept

private static void AcceptCallback(IAsyncResult result)
{
    var listener = (Socket)result.AsyncState;
    var handler = listener.EndAccept(result);

    var state = new StateObject();
    state.WorkSocket = handler;

    LbConnections.Add(new SimClient { State = state });
    handler.BeginReceive(state.Buffer, 0, StateObject.BufferSize, SocketFlags.None, ReceiveCallback, state);
    ServerSocket.BeginAccept(AcceptCallback, ServerSocket);  // <<---
}

它的工作原理与BeginReceive 和EndReceive 相同。

在这种情况下，await Task.Run(() => 是无用的。你混合了两种不同的方法。 TPL 和异步回调。

【讨论】：

【解决方案2】：

如果我移动 ServerSocket.BeginAccept(AcceptCallback, ServerSocket);在 AcceptCallback 中，AcceptCallback 不会被任何时候调用。

编辑我发现了错误。我需要调用 ServerSocket.BeginAccept(AcceptCallback, listener); 谢谢:)

【讨论】：