Question

我的服务器/监听器有ADD或没有耐力;什么是解毒剂或产品？

该应用程序充当套接字通信的两端。它似乎适用于第一条消息（我在textBox1中输入“Bla”，然后label1读取“Bla back atcha”，但它在后续消息中失败。我在我的开发机器上运行了一个应用程序实例，另一个实例（在其他计算机上重命名为包含“服务器”一词）。

我已经粘贴了下面的代码，并且错误的消息我第二次尝试发送消息（“因为目标机器主动拒绝它而无法建立连接10.24.93.110:51111").

当我在另一台机器上启动“Server”实例并在命令行中运行“netstat -a”时，它表示服务器机器正在侦听端口51111上的dev机器。

传递第一条消息后，显然收到并抛回，运行“netstat -a”仍显示与我的开发机器的连接，但该状态不再是LISTENING而是TIME_WAIT。

然后，我尝试传递另一条消息，我得到了错误的消息（下面的图表B）

附件A：来源

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.Diagnostics;

namespace testSocketSendAndReceive_Nutshell
{
    public partial class Form1 : Form
    {
        string sJerrysIPAddr = "10.24.31.110";
        string sMyIPAddr = "10.24.31.128";
        string sThisAppFileName = string.Empty;
        bool bThisInstanceFunctionsAsServer = false;

        internal static Form1 MainSocketPairForm = null;

        public Form1()
        {
            InitializeComponent();
            MainSocketPairForm = this;
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            sThisAppFileName = System.Diagnostics.Process.GetCurrentProcess().ProcessName;
            lblFileName.Text = sThisAppFileName;

            // Client and Server code are here combined in one app; however, we want each instance to run as
            // just one or the other, so (the .exe functioning as a Server should be renamed with the subString
            // "Server" somewhere in the filename):
            bThisInstanceFunctionsAsServer = sThisAppFileName.Contains("Server");
            if (bThisInstanceFunctionsAsServer)
            {
                new Thread(Server).Start();       // Run server method concurrently.
                Thread.Sleep(500);                // Give server time to start.
            }
            btnSendMsg.Visible = !bThisInstanceFunctionsAsServer;
        }

        static void Client()
        {
            using (TcpClient client = new TcpClient(Form1.MainSocketPairForm.sJerrysIPAddr, 51111)) // err here second time 
            using (NetworkStream n = client.GetStream())
            {
                BinaryWriter w = new BinaryWriter(n);
                w.Write(Form1.MainSocketPairForm.textBox1.Text.ToString());
                w.Flush();
                Form1.MainSocketPairForm.label1.Text = new BinaryReader(n).ReadString();
            }
        }

        static void Server()     // Handles a single client request, then exits.
        {
            TcpListener listener = new TcpListener(IPAddress.Any, 51111);
            listener.Start(); //Only one usage of each socket address (protocol/network address/port) is normally permitted
            // got the above err msg with an instance running and listening on jerry's machine
            // continues to listen even after shut down...
            using (TcpClient c = listener.AcceptTcpClient())
            using (NetworkStream n = c.GetStream())
            {
                string msg = new BinaryReader(n).ReadString();
                BinaryWriter w = new BinaryWriter(n);
                w.Write(msg + " back atcha!");
                w.Flush(); // Must call Flush because we're not disposing the writer.
            }
            listener.Stop();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Client();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            Close();
        }
    }
}

EXHIBIT B：完整错误消息

System.Net.Sockets.SocketException未处理消息=“无法建立连接，因为目标计算机主动拒绝它10.24.93.110:51111” 来源=“系统” 错误码= 10061 NativeErrorCode = 10061 堆栈跟踪：在System.Net.Sockets.TcpClient..ctor（String hostname，Int32 port）在testSocketSendAndReceive_Nutshell.Form1.Client（）中 C：\ testSocketSendAndReceive_Nutshell \ testSocketSendAndReceive_Nutshell \ Form1.cs：第57行 at testSocketSendAndRendive_Nutshell.Form1.button1_Click（Object sender，EventArgs e）位于C：\ testSocketSendAndReceive_Nutshell \ testSocketSendAndReceive_Nutshell \ Form1.cs：第90行，位于System.Windows.Forms.Control.OnClick（EventArgs e）在System.Windows.Forms.Button.OnClick（EventArgs e）在System.Windows.Forms.Button.OnMouseUp（MouseEventArgs mevent）在System.Windows.Forms.Control.WmMouseUp（消息＆amp; m，MouseButtons按钮，Int32点击）在System.Windows.Forms.Control.WndProc（消息＆amp; m）在System.Windows.Forms.ButtonBase.WndProc（消息＆amp; m）在System.Windows.Forms.Button.WndProc（消息＆amp; m）在System.Windows.Forms.Control.ControlNativeWindow.OnMessage（Message＆amp; m）在System.Windows.Forms.Control.ControlNativeWindow.WndProc（Message＆amp; m）在System.Windows.Forms.NativeWindow.DebuggableCallback（IntPtr hWnd，Int32 msg，IntPtr wparam，IntPtr lparam）在System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW（MSG＆amp; msg）在System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop（Int32 dwComponentID，Int32 reason，Int32 pvLoopData）在System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner（Int32原因， ApplicationContext context）在System.Windows.Forms.Application.ThreadContext.RunMessageLoop（Int32 reason，ApplicationContext）上下文）在System.Windows.Forms.Application.Run（Form mainForm）在testSocketSendAndReceive_Nutshell.Program.Main（）中 C：\ testSocketSendAndReceive_Nutshell \ testSocketSendAndReceive_Nutshell \ Program.cs：第18行在System.AppDomain._nExecuteAssembly（Assembly assembly，String [] args）在System.AppDomain.ExecuteAssembly（String assemblyFile，Evidence assemblySecurity，String [] args）在Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly（）在System.Threading.ThreadHelper.ThreadStart_Context（对象状态）在System.Threading.ExecutionContext.Run（ExecutionContext executionContext，ContextCallback回调，对象状态）在System.Threading.ThreadHelper.ThreadStart（） InnerException：

Answer 1

查看服务器代码开头的注释

static void Server()     // Handles a single client request, then exits.

这是完全正确的 - 你打电话给AcceptTcpClient一次，回应，然后关闭听众。那只会处理一个连接。如果你想要它处理多个连接，你需要循环 - 很可能在循环并再次接受之前将每个TCP客户端交给一个单独的线程。

Answer 2

您对Server()方法的评论会回答您自己的问题：

// Handles a single client request, then exits.

读完第一个字符串后，调用listener.Stop()然后从函数返回，以便线程退出。如果您希望服务器为后续请求保持活跃状态，那么您将不得不采用某种循环方式。

Answer 3

在您的服务器上，您在收到第一条消息后正在处理客户端。

如果要保持TCP连接处于活动状态，则需要在服务器方法中保存TCP客户端。然后你可以使用像client.GetStream().Read()这样的方法来读取客户端的数据。请注意，此方法将阻止，直到您从流中收到消息。

为了处理n个请求，你必须做一些循环：

while(true) {
   string msg = client.GetStream().Read();
   // do something with the message
}

还有一些异步方法可以让您在另一个线程上执行这些操作。查看流上的BeginRead()方法。

Answer 4

~~发送响应后需要调用client.Close()。~~你还需要循环服务器的接受逻辑：

var shouldExit == false;
while (!shouldExit)
    using (TcpClient c = listener.AcceptTcpClient())
    {
        using (NetworkStream n = c.GetStream())
        {
            string msg = new BinaryReader(n).ReadString();
            if (msg == "exit")
                // Client told us to exit...
                shouldExit = true;
            BinaryWriter w = new BinaryWriter(n);
            w.Write(msg + " back atcha!");
            w.Flush(); // Must call Flush because we're not disposing the writer.
        }
    }

这就是文档中的示例：http://msdn.microsoft.com/en-us/library/system.net.sockets.tcplistener.aspx

我的服务器/监听器缺少True Grit

4 个答案: