用Socket 做的一个聊天小程序，为什么总是丢包，如何解决

Question

为了学习Socket，从网上down了一下实例，进行调试学习，程序很简单，就是服务端和客户端进行对话聊天，但是发现在连续发送内容时，有的信息收不到，没有反应。这是怎么回事，是不是传说的丢包问题，怎样才能解决，实现稳定的对话。
不是都收不到，现在是不稳定，快速输入，点发送，有的能收到，有的就收不到。
谢谢

Answer 1

服务端代码：
namespace ServerSocketForms
{
    public partial class ServerSocketTestForm : Form
    {
        #region 变量列表
        /// <summary>
        /// 服务端SOCKET对象
        /// </summary>
        private Socket ServerSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);        /// <summary>
        /// 客户端SOCKET
        /// </summary>
        private Socket ClientSocket = null;        /// <summary>
        /// 客户端终结点
        /// </summary>
        private IPEndPoint ClientEndPoint = null;        /// <summary>
        /// 服务端终结点
        /// </summary>
        private IPEndPoint ServerEndPoint = null;        /// <summary>
        /// 客户端终结点端口
        /// </summary>
        private const int CLIENT_END_POINT_PORT = 5566;        /// <summary>
        /// 服务器端终结点端口
        /// </summary>
        private const int SERVER_END_POINT_PORT = 5533;
        #endregion        #region 构造函数
        public ServerSocketTestForm()
        {
            InitializeComponent();
        }
        #endregion        #region 事件列表        /// <summary>
        /// 窗体加载事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Form1_Load(object sender, EventArgs e)
        {
            Control.CheckForIllegalCrossThreadCalls = false;            ThreadServerListen();            txtContent.Focus();
        }        /// <summary>
        /// 向客户端发送数据
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnClientSend_Click(object sender, EventArgs e)
        {
            ThreadClientrSendData();
        }        /// <summary>
        /// 关闭程序
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnExit_Click(object sender, EventArgs e)
        {
            Environment.Exit(0);
        }
        #endregion        #region 函数列表
        #region Server
        /// <summary>
        /// 开始监听
        /// </summary>
        private void StartServerListenAndReceiveData()
        {
            try
            {
                //如果没有绑定则执行绑定当地终结点操作
                if (!ServerSocket.IsBound)
                {
                    //设置终结点
                    SetEndPoint();                    //绑定本地结点
                    ServerSocket.Bind(ServerEndPoint);                    //开启监听
                    ServerSocket.Listen(20);                    listBox1.Items.Add(string.Format("成功开启监听({0}:{1})[{2}]", ServerEndPoint.Address, ServerEndPoint.Port, DateTime.Now.ToString()));                    ClientSocket = ServerSocket.Accept();
                }                //接收数据开始
                ServerReceiveData();
            }
            catch
            {
                MessageBox.Show(string.Format("开启监听{0}:{1}失败！请检查服务端IP地址是否配置正确。", ServerEndPoint.Address, ServerEndPoint.Port), "提示", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }        /// <summary>
        /// 线程监听操作
        /// </summary>
        private void ThreadServerListen()
        {
            //接收数据线程
            Thread ReceiveThread = new Thread(new ThreadStart(StartServerListenAndReceiveData));            //后台运行
            ReceiveThread.IsBackground = true;            //开启线程
            ReceiveThread.Start();
        }        /// <summary>
        /// 接收数据
        /// </summary>
        private void ServerReceiveData()
        {
            try
            {
                while (true)
                {
                    Thread.Sleep(1);
                    byte[] bytes = new byte[ClientSocket.Available];                    //接收数据
                    int butter = ClientSocket.Receive(bytes);                    if (butter > 0)
                    {
                        string strData = string.Format("{0}", Encoding.UTF8.GetString(bytes));
                        listBox1.Items.Add(string.Format("[{0}][{1}]", ((IPEndPoint)ClientSocket.RemoteEndPoint).Address, DateTime.Now.ToString()));
                        listBox1.Items.Add(string.Format("  {0}", strData));
                        listBox1.SelectedIndex = listBox1.Items.Count - 1;
                    }                    //客户端SOCKET
                    ClientSocket = ServerSocket.Accept();
                }
            }
            catch (Exception err)
            {
                MessageBox.Show(err.ToString());
            }
        }
        #endregion        #region Client        /// <summary>
        /// 线程发送数据
        /// </summary>
        private void ThreadClientrSendData()
        {
            Thread thread = new Thread(new ThreadStart(ClientSendData));
            thread.IsBackground = true;
            thread.Priority = ThreadPriority.Highest;
            thread.Start();
        }        /// <summary>
        /// 发送数据
        /// </summary>
        private void ClientSendData()
        {
            if (string.IsNullOrEmpty(txtContent.Text.Trim()))
            {
                MessageBox.Show("请填写消息内容。", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                txtContent.Focus();
                return;
            }
            try
            {
                if (ClientSocket == null)
                {
                    MessageBox.Show("没有可用的连接。", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                    return;
                }                btnClientSend.Enabled = false;
                btnClientSend.Text = "发送中...";
                byte[] bytes = null;                bytes = Encoding.UTF8.GetBytes(txtContent.Text.Trim());                //重新调整客户端端口号
                ClientEndPoint = (IPEndPoint)ClientSocket.RemoteEndPoint;
                ClientEndPoint = new IPEndPoint(ClientEndPoint.Address, CLIENT_END_POINT_PORT);                Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);                socket.Connect(ClientEndPoint);                //向客户端发送数据
                socket.Send(bytes);
                socket.Close();                listBox1.Items.Add(string.Format("[{0}][{1}]", ((IPEndPoint)ServerSocket.LocalEndPoint).Address, DateTime.Now.ToString()));                listBox1.Items.Add(string.Format("  {0}", txtContent.Text.Trim()));
                listBox1.SelectedIndex = listBox1.Items.Count - 1;                btnClientSend.Enabled = true;
                btnClientSend.Text = "发送";                txtContent.Text = "";
                txtContent.Focus();
            }
            catch
            {
                MessageBox.Show(string.Format("服务器{0}:{1}连接失败！请检查目标机器端口号{1}是否被占用。", ClientEndPoint.Address, ClientEndPoint.Port), "提示", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
        #endregion        /// <summary>
        /// 设置服务器端终结点
        /// </summary>
        private void SetEndPoint()
        {
            IPHostEntry hostEntry = Dns.GetHostByName(Dns.GetHostName());            IPAddress address = hostEntry.AddressList[0];//5_1_a_s_p_x            ServerEndPoint = new IPEndPoint(address, SERVER_END_POINT_PORT);
        }
        #endregion
    }
}

Answer 2

客户端代码：namespace ClientSocketForms
{
    public partial class ClientSocketTestForm : Form
    {
               /// 客户端终结点端口
               private const int CLIENT_END_POINT_PORT = 5566;        /// <summary>
        /// 服务器端终结点端口
        /// </summary>
        private const int SERVER_END_POINT_PORT = 5533;        /// <summary>
        /// ****************此处要改成服务器的IP，否则程序将运行不起来****************
        /// </summary>
        private static string SERVER_IP
        {
            get
            {
                return global::ClientSocketForms.Properties.Settings.Default.ServerIP;
            }
        }        /// <summary>
        /// 服务器结点
        /// </summary>
        private IPEndPoint ServerEndPoint = null;        /// <summary>
        /// 客户端SOCKET
        /// </summary>
        private Socket ClientSocket = null;        /// <summary>
        /// 服务端SOCKET
        /// </summary>
        private Socket ServerSocket = null;        /// <summary>
        /// 客户端监听SOCKET
        /// </summary>
        private Socket ClientListenSocket = null;
        #endregion        #region 构造函数
        public ClientSocketTestForm()
        {
            InitializeComponent();
        }
        #endregion        #region 事件列表
        /// <summary>
        /// 发送消息事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button1_Click(object sender, EventArgs e)
        {
            ThreadSendData();
        }        /// <summary>
        /// 关闭程序
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnExit_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }        /// <summary>
        /// 页面加载事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Form1_Load(object sender, EventArgs e)
        {
            Control.CheckForIllegalCrossThreadCalls = false;            //接收服务器端数据
            ThreadReceiveData();
        }        /// <summary>
        /// 清空列表框
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnClear_Click(object sender, EventArgs e)
        {
            listBox1.Items.Clear();
        }       /// 打开服务器IP配置窗口
        private void 服务器IP设置ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            ServerIPForm ServerIp = new ServerIPForm();
            ServerIp.ShowDialog();
        }
        #endregion        #region 方法列表
        /// <summary>
        /// 向服务器发送数据
        /// </summary>
        private void SendData()
        {
            IPAddress ServerIPAdd = null;            if (!IPAddress.TryParse(SERVER_IP, out ServerIPAdd))
            {
                MessageBox.Show("服务器端IP地址配置不正确！请重新配置服务器端IP地址。", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);                //显示服务器IP配置界面
                ServerIPForm frmIp = new ServerIPForm();
                frmIp.ShowDialog();
                return;
            }            ServerEndPoint = new IPEndPoint(ServerIPAdd, SERVER_END_POINT_PORT);
            if (string.IsNullOrEmpty(txtContent.Text.Trim()))
            {
                MessageBox.Show("请填写消息内容。", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                txtContent.Focus();
                return;
            }            try
            {
                button1.Enabled = false;
                button1.Text = "发送中...";                //客户端SOCKET
                ClientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);                //建立与服务器端的连接
                ClientSocket.Connect(ServerEndPoint);                byte[] bytes = new byte[1024];                bytes = Encoding.UTF8.GetBytes(txtContent.Text.Trim());                ClientSocket.Send(bytes);
                ClientSocket.Shutdown(SocketShutdown.Both);
                listBox1.Items.Add(string.Format("[{0}][{1}]", ((IPEndPoint)ClientSocket.LocalEndPoint).Address, DateTime.Now.ToString()));                listBox1.Items.Add(string.Format("  {0}", txtContent.Text.Trim()));
                ClientSocket.Close();
                listBox1.SelectedIndex = listBox1.Items.Count - 1;                txtContent.Text = "";
                txtContent.Focus();                button1.Enabled = true;
                button1.Text = "发送";
            }
            catch (Exception err)
            {
                MessageBox.Show(string.Format("服务器{0}:{1}连接失败！请检查目标机器IP是否正确。", ServerEndPoint.Address, ServerEndPoint.Port), "提示", MessageBoxButtons.OK, MessageBoxIcon.Error);                button1.Enabled = true;
                button1.Text = "发送";                //显示服务器IP配置界面
                ServerIPForm frmIp = new ServerIPForm();
                frmIp.ShowDialog();
                return;
            }
        }        /// <summary>
        /// 线程发送数据
        /// </summary>
        private void ThreadSendData()
        {
            Thread thread = new Thread(new ThreadStart(SendData));
            thread.IsBackground = true;
            thread.Priority = ThreadPriority.Highest;
            thread.Start();
        }        /// <summary>
        /// 开始监听
        /// </summary>
        private void StartClientListenAndReceiveData()
        {
            //客户端侦听SOCKET
            ClientListenSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);            IPHostEntry hostEntry = Dns.GetHostByName(Dns.GetHostName());            IPAddress address = hostEntry.AddressList[0];            try
            {
                //绑定本地结点并开启本地监听
                if (!ClientListenSocket.IsBound)
                {
                    ClientListenSocket.Bind(new IPEndPoint(address, CLIENT_END_POINT_PORT));
                    ClientListenSocket.Listen(20);
                }                listBox1.Items.Add(string.Format("成功开启监听({0}:{1})[{2}]。", address, CLIENT_END_POINT_PORT, DateTime.Now.ToString()));                //接收数据
                ServerReceiveData();
            }
            catch
            {
                MessageBox.Show(string.Format("服务器{0}:{1}连接失败！请检查目标机器端口号{1}是否被占用。", address, CLIENT_END_POINT_PORT), "提示", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }        /// <summary>
        /// 接收服务端数据
        /// </summary>
        private void ServerReceiveData()
        {
            try
            {
                while (true)
                {
                    Thread.Sleep(1);
                    //服务端SOCKET
                    ServerSocket = ClientListenSocket.Accept();
                    byte[] bytes = new byte[ServerSocket.Available];
                    //接收数据
                    int butter = ServerSocket.Receive(bytes);
                    if (butter > 0)
                    {
                        string strData = string.Format("{0}", Encoding.UTF8.GetString(bytes));
                        listBox1.Items.Add(string.Format("[{0}][{1}]", ((IPEndPoint)ServerSocket.RemoteEndPoint).Address, DateTime.Now.ToString()));
                        listBox1.Items.Add(string.Format("  {0}", strData));
                        listBox1.SelectedIndex = listBox1.Items.Count - 1;
                    }
                }
            }
            catch (Exception err)
            {
                MessageBox.Show(err.ToString());
            }
        }
        /// <summary>
        /// 线程接收数据
        /// </summary>
        private void ThreadReceiveData()
        {
            Thread thread = new Thread(new ThreadStart(StartClientListenAndReceiveData));
            thread.IsBackground = true;
            thread.Start();
        }
        #endregion
    }
}

Answer 3

tcp应该不会丢包的，如果丢包，应该是网络的问题，

Answer 4

这种代码.........到处都是惨不忍睹的。随便找一个吧，string strData = string.Format("{0}", Encoding.UTF8.GetString(bytes));
这里bytes中只有前buffer个字节是你接收到内容，怎么能把整个bytes作为接收到的内容呢？

Answer 5

再比如说吧，你的所谓“服务器端”仅仅在Form初始化时ServerSocket.Listen(20);
ClientSocket = ServerSocket.Accept();
ServerReceiveData();
而你的所谓“客户端”则是每当btnClientSend_Click时弄个所谓线程去单独调用ClientSendData，这能够让你服务器获得第二个会话？晕啊。我不知道你从哪里抄来的代码。我建议你把这些代码简化到20行以内（只要了解必要的几行代码就够了），或者干脆删除（另外找人学习）。另外请告诉我你是从哪里抄来的代码？这其实很重要。我们可以知道这是哪一个坑人的培训学校的教学。