服务器客户端发送/接收简单文本

Question

我有一个作业来构建一个应用程序，它将在服务器和客户端之间发送和接收简单的字符串。我知道如何建立连接，但不知道如何发送和接收字符串。这是我的代码：

public partial class Form1 : Form
{
    private Thread n_server;
    private Thread n_client;
    private Thread n_send_server;
    private TcpClient client;
    private TcpListener listener;
    private int port = 2222;
    private string IP = " ";
    private Socket socket;
    public Form1()
    {
        InitializeComponent();
    }

    private void exitToolStripMenuItem_Click(object sender, EventArgs e)
    {
        Application.Exit();
    }

    public void Server()
    {
        listener = new TcpListener(IPAddress.Any, port);
        listener.Start();
        try
        {
            socket = listener.AcceptSocket();
            if (socket.Connected)
            {
                textBox2.Invoke((MethodInvoker)delegate { textBox2.Text = "Client : " + socket.RemoteEndPoint.ToString(); });
            }
        }
        catch
        {
        }
    }

    public void Client()
    {
        IP = "localhost";
        client = new TcpClient();
        try
        {
            client.Connect(IP, port);
        }

        catch (Exception ex)
        {
            MessageBox.Show("Error : " + ex.Message);
        }

        if (client.Connected)
        {
            textBox3.Invoke((MethodInvoker)delegate { textBox3.Text = "Connected..."; });

        }
    }

    private void button1_Click(object sender, EventArgs e)
    {
        n_server = new Thread(new ThreadStart(Server)); 
        n_server.IsBackground = true;
        n_server.Start();
        textBox1.Text = "Server up";
    }

    private void button2_Click(object sender, EventArgs e)
    {
        n_client = new Thread(new ThreadStart(Client));
        n_client.IsBackground = true;
        n_client.Start();
    }

    private void send()
    {
        // I want to use this method for both buttons : "send button" on server side    and "send button"
        // on client side. First I read text from textbox2 on server side or textbox3
        // on client side than accept and write the string to label2(s) or label3(c).
        // 
    }


    private void button3_Click(object sender, EventArgs e)
    {
        n_send_server = new Thread(new ThreadStart(send));
        n_send_server.IsBackground = true;
        n_send_server.Start();
    }
}

Answer 1

以下代码向服务器发送和接收当前日期和时间

//以下代码用于服务器应用程序：

namespace Server
{
    class Program
    {
        const int PORT_NO = 5000;
        const string SERVER_IP = "127.0.0.1";

        static void Main(string[] args)
        {
            //---listen at the specified IP and port no.---
            IPAddress localAdd = IPAddress.Parse(SERVER_IP);
            TcpListener listener = new TcpListener(localAdd, PORT_NO);
            Console.WriteLine("Listening...");
            listener.Start();

            //---incoming client connected---
            TcpClient client = listener.AcceptTcpClient();

            //---get the incoming data through a network stream---
            NetworkStream nwStream = client.GetStream();
            byte[] buffer = new byte[client.ReceiveBufferSize];

            //---read incoming stream---
            int bytesRead = nwStream.Read(buffer, 0, client.ReceiveBufferSize);

            //---convert the data received into a string---
            string dataReceived = Encoding.ASCII.GetString(buffer, 0, bytesRead);
            Console.WriteLine("Received : " + dataReceived);

            //---write back the text to the client---
            Console.WriteLine("Sending back : " + dataReceived);
            nwStream.Write(buffer, 0, bytesRead);
            client.Close();
            listener.Stop();
            Console.ReadLine();
        }
    }
}

//这是客户端的代码

namespace Client
{
    class Program
    {
        const int PORT_NO = 5000;
        const string SERVER_IP = "127.0.0.1";
        static void Main(string[] args)
        {
            //---data to send to the server---
            string textToSend = DateTime.Now.ToString();

            //---create a TCPClient object at the IP and port no.---
            TcpClient client = new TcpClient(SERVER_IP, PORT_NO);
            NetworkStream nwStream = client.GetStream();
            byte[] bytesToSend = ASCIIEncoding.ASCII.GetBytes(textToSend);

            //---send the text---
            Console.WriteLine("Sending : " + textToSend);
            nwStream.Write(bytesToSend, 0, bytesToSend.Length);

            //---read back the text---
            byte[] bytesToRead = new byte[client.ReceiveBufferSize];
            int bytesRead = nwStream.Read(bytesToRead, 0, client.ReceiveBufferSize);
            Console.WriteLine("Received : " + Encoding.ASCII.GetString(bytesToRead, 0, bytesRead));
            Console.ReadLine();
            client.Close();
        }
    }
}

Answer 2

    static void Main(string[] args)
    {
        //---listen at the specified IP and port no.---
        IPAddress localAdd = IPAddress.Parse(SERVER_IP);
        TcpListener listener = new TcpListener(localAdd, PORT_NO);
        Console.WriteLine("Listening...");
        listener.Start();
        while (true)
        {
            //---incoming client connected---
            TcpClient client = listener.AcceptTcpClient();

            //---get the incoming data through a network stream---
            NetworkStream nwStream = client.GetStream();
            byte[] buffer = new byte[client.ReceiveBufferSize];

            //---read incoming stream---
            int bytesRead = nwStream.Read(buffer, 0, client.ReceiveBufferSize);

            //---convert the data received into a string---
            string dataReceived = Encoding.ASCII.GetString(buffer, 0, bytesRead);
            Console.WriteLine("Received : " + dataReceived);

            //---write back the text to the client---
            Console.WriteLine("Sending back : " + dataReceived);
            nwStream.Write(buffer, 0, bytesRead);
            client.Close();
        }
        listener.Stop();
        Console.ReadLine();
    }

除了@Nudier Mena 回答之外，还保留一个while 循环以保持服务器处于侦听模式。这样我们就可以连接多个客户端实例。

Answer 3

   public partial class Form1 : Form
    {
        private Thread n_server;
        private Thread n_client;
        private Thread n_send_server;
        private TcpClient client;
        private TcpListener listener;
        private int port = 2222;
        private string IP = " ";
        private Socket socket;
        byte[] bufferReceive = new byte[4096];
        byte[] bufferSend = new byte[4096];
        public Form1()
        {
            InitializeComponent();
        }

        private void exitToolStripMenuItem_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }

        public void Server()
        {
            listener = new TcpListener(IPAddress.Any, port);
            listener.Start();
            try
            {
                socket = listener.AcceptSocket();
                if (socket.Connected)
                {
                    textBox3.Invoke((MethodInvoker)delegate { textBox3.Text = "Client        : " + socket.RemoteEndPoint.ToString(); });
                }
                while (true)
                {
                    int length = socket.Receive(bufferReceive);
                    if (length > 0)
                    {
                        label2.Invoke((MethodInvoker)delegate { label2.Text = Encoding.Unicode.GetString(bufferReceive); });
                    }
                }
            }
            catch
            {
            }
        }

        public void Client()
        {
            IP = "localhost";
            client = new TcpClient();
            try
            {
                client.Connect(IP, port);
                while (true)
                {
                    NetworkStream nts = client.GetStream();
                    int length;
                    while ((length = nts.Read(bufferReceive, 0, bufferReceive.Length)) != 0)
                    {
                       label3.Invoke((MethodInvoker)delegate { label3.Text = Encoding.Unicode.GetString(bufferReceive); });
                    }
                }
            }

            catch (Exception ex)
            {
                MessageBox.Show("Error : " + ex.Message);
            }

            if (client.Connected)
            {
                textBox3.Invoke((MethodInvoker)delegate { textBox3.Text = "Connected..."; });

            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            n_server = new Thread(new ThreadStart(Server));
            n_server.IsBackground = true;
            n_server.Start();
            textBox1.Text = "Server up";
        }

        private void button2_Click(object sender, EventArgs e)
        {
            n_client = new Thread(new ThreadStart(Client));
            n_client.IsBackground = true;
            n_client.Start();
        }

        private void send()
        {
            if (socket!=null)
            {
                bufferSend = Encoding.Unicode.GetBytes(textBox2.Text);
                socket.Send(bufferSend);
            }
            else
            {
                if (client.Connected)
                {
                    bufferSend = Encoding.Unicode.GetBytes(textBox3.Text);
                    NetworkStream nts = client.GetStream();
                    if (nts.CanWrite)
                    {
                        nts.Write(bufferSend,0,bufferSend.Length);
                    }

                }
            }
        }



        private void button3_Click(object sender, EventArgs e)
        {
            n_send_server = new Thread(new ThreadStart(send));
            n_send_server.IsBackground = true;
            n_send_server.Start();
        }
    }

Answer 4

bool SendReceiveTCP(string ipAddress, string sendMsg, ref string recMsg)
    {
        try
        {
            DateTime startTime=new DateTime();
            TcpClient clt = new TcpClient();
            clt.Connect(ipAddress, 8001);
            NetworkStream nts = clt.GetStream();
            nts.Write(Encoding.ASCII.GetBytes(sendMsg),0, sendMsg.Length);
            startTime = DateTime.Now;
            while (true)
            {
                if (nts.DataAvailable)
                {
                    byte[] tmpBuff = new byte[1024];
                    System.Threading.Thread.Sleep(100);
                    int readOut=nts.Read(tmpBuff, 0, 1024);
                    if (readOut > 0)
                    {
                        recMsg = Encoding.ASCII.GetString(tmpBuff, 0, readOut);
                        nts.Close();
                        clt.Close();
                        return true;
                    }
                    else
                    {
                        nts.Close();
                        clt.Close();
                        return false;
                    }
                }
                TimeSpan tps = DateTime.Now - startTime;
                if (tps.TotalMilliseconds > 2000)
                {
                    nts.Close();
                    clt.Close();
                    return false;
                }
                System.Threading.Thread.Sleep(50);
            }
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }

Answer 5

客户

namespace SocketKlient

{
    class Program

    {
        static Socket Klient;
        static IPEndPoint endPoint;
        static void Main(string[] args)
        {
            Klient = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            string command;
            Console.WriteLine("Write IP address");
            command = Console.ReadLine();
            IPAddress Address;
            while(!IPAddress.TryParse(command, out Address)) 
            {
                Console.WriteLine("wrong IP format");
                command = Console.ReadLine();
            }
            Console.WriteLine("Write port");
            command = Console.ReadLine();

            int port;
            while (!int.TryParse(command, out port) && port > 0)
            {
                Console.WriteLine("Wrong port number");
                command = Console.ReadLine();
            }
            endPoint = new IPEndPoint(Address, port); 
            ConnectC(Address, port);
            while(Klient.Connected)
            {
                Console.ReadLine();
                Odesli();
            }
        }

        public static void ConnectC(IPAddress ip, int port)
        {
            IPEndPoint endPoint = new IPEndPoint(ip, port);
            Console.WriteLine("Connecting...");
            try
            {
                Klient.Connect(endPoint);
                Console.WriteLine("Connected!");
            }
            catch
            {
                Console.WriteLine("Connection fail!");
                return; 
            }
            Task t = new Task(WaitForMessages); 
            t.Start(); 
        }

        public static void SendM()
        {
            string message = "Actualy date is " + DateTime.Now; 
            byte[] buffer = Encoding.UTF8.GetBytes(message);
            Console.WriteLine("Sending: " + message);
            Klient.Send(buffer);
        }

        public static void WaitForMessages()
        {
            try
            {
                while (true)
                {
                    byte[] buffer = new byte[64]; 
                    Console.WriteLine("Waiting for answer");
                    Klient.Receive(buffer, 0, buffer.Length, 0); 

                    string message = Encoding.UTF8.GetString(buffer); 
                    Console.WriteLine("Answer: " + message); 
                }
            }
            catch
            {
                Console.WriteLine("Disconnected");
            }
        }
    }
}

Answer 6

服务器：

namespace SocketServer    
{
    class Program
    {
        static Socket klient; 
        static void Main(string[] args)
        {
            Socket server = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); 
            IPEndPoint endPoint = new IPEndPoint(IPAddress.Any, 8888); 
            server.Bind(endPoint);
            server.Listen(20);
            while(true)
            {
                Console.WriteLine("Waiting...");
                klient = server.Accept();

                Console.WriteLine("Client connected");
                Task t = new Task(ServisClient);
                t.Start();
            }
        }

        static void ServisClient()
        {
            try
            {
                while (true)
                {
                    byte[] buffer = new byte[64];
                    Console.WriteLine("Waiting for answer...");
                    klient.Receive(buffer, 0, buffer.Length, 0);
                    string message = Encoding.UTF8.GetString(buffer);
                    Console.WriteLine("Answer: " + message);

                    string answer = "Actualy date is " + DateTime.Now;
                    buffer = Encoding.UTF8.GetBytes(answer);
                    Console.WriteLine("Sending {0}", answer);
                    klient.Send(buffer);
                }
            }
            catch
            {
                Console.WriteLine("Disconnected");
            }
        }
    }
}