Clien-Server to run on different machines and multiple clients

Question

I have wrote a client server program using C#, the programm runs on the same machine, the client sends a message and the server displays te message, how can i edit my program so that both server and client run on different machines, and also that 10 clients can connect to the server

Here is my Client Code:

public partial class ClientForm : Form
    {
        const int BUFFER_SIZE = 1024;
        byte[] sendBuffer = new byte[BUFFER_SIZE];
        byte[] rcvBuffer = new byte[BUFFER_SIZE];

        Socket clientSocket;
        const int PORT = 3333;

        public ClientForm()
        {
            InitializeComponent();
        }

        void btnConnect_Click(object sender, EventArgs e)
        {
            try
            {
                clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                // Connect to the local host
                clientSocket.Connect(new IPEndPoint(IPAddress.Loopback, PORT));
            }
            catch (Exception ex) { AppendToTextBox(ex.Message); }

            EnableSendButton();
        }

        void btnSend_Click(object sender, EventArgs e)
        {
            try
            {
                // Serialize the textBox text before sending
                sendBuffer = Encoding.ASCII.GetBytes(textBoxInput.Text);

                // Sends contents of textbox to the server
                clientSocket.Send(sendBuffer);

                // Prepares to receive something, i.e. the echo
                clientSocket.BeginReceive(rcvBuffer, 0, rcvBuffer.Length, SocketFlags.None, ReceiveCallback, null);//.Receive(rcvBuffer);
            }
            catch (Exception ex) { AppendToTextBox(ex.Message); }
        }

        // About Asynchronous Callbacks: http://stackoverflow.com/questions/1047662/what-is-asynccallback
        void ReceiveCallback(IAsyncResult AR)
        {
            try
            {
                int bytesReceived = clientSocket.EndReceive(AR);    // Number of bytes received
                byte[] rcvBufferTrim = new byte[bytesReceived];
                Array.Copy(rcvBuffer, rcvBufferTrim, bytesReceived);    // Removes trailing nulls
                string text = Encoding.ASCII.GetString(rcvBufferTrim);  // Convert bytes into string
                AppendToTextBox(DateTime.Now.ToString("HH:mm:ss") + ": " + text);       // Displays buffer contents as text

                // Starts receiving data again
                clientSocket.BeginReceive(rcvBuffer, 0, rcvBuffer.Length, SocketFlags.None, ReceiveCallback, null);
            }
            catch (Exception ex) { AppendToTextBox(ex.Message); }
        }
}

and the server code:

public partial class ServerForm : Form
    {
const int BUFFER_SIZE = 1024;
        byte[] rcvBuffer = new byte[BUFFER_SIZE];   // To recieve data from the client

        Socket serverSocket;
        Socket clientSocket; // We will only accept one client socket for now
        const int PORT = 3333;

        public ServerForm()
        {
            InitializeComponent();

            StartServer();
        }



        void StartServer()
        {
            try
            {

                serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                serverSocket.Bind(new IPEndPoint(IPAddress.Any, PORT));
                serverSocket.Listen(10);        // Listen(1) means a maximum of one client pending
                serverSocket.BeginAccept(AcceptCallback, null);








            }
            catch (Exception ex) { AppendToTextBox(ex.Message); }
        }

        // About Asynchronous Callbacks: http://stackoverflow.com/questions/1047662/what-is-asynccallback
        void AcceptCallback(IAsyncResult AR)
        {

            try
            {   

                clientSocket = serverSocket.EndAccept(AR);  // Client connected successfully, waiting for requests
                AppendToTextBox("Client connected successfully...");
                clientSocket.BeginReceive(rcvBuffer, 0, rcvBuffer.Length, SocketFlags.None, ReceiveCallback, null);
            }
            catch (Exception ex) { AppendToTextBox(ex.Message); }
        }


        void ReceiveCallback(IAsyncResult AR)
        {
            try
            {
                int bytesReceived = clientSocket.EndReceive(AR);    // Number of bytes received
                byte[] rcvBufferTrim = new byte[bytesReceived];
                Array.Copy(rcvBuffer, rcvBufferTrim, bytesReceived);    // Removes trailing nulls
                string text = Encoding.ASCII.GetString(rcvBufferTrim);  // Convert bytes into string
                AppendToTextBox("Received Text: " + text);


                if (text == "getdate") 
                    text = "\t"+ System.DateTime.Now.ToString("dd.MM.yyyy");
                else if (text == "gettime") 
                    text = "\t"+ System.DateTime.Now.ToString("h:mm:ss ");

                ///////////////////////////////////////////////////////////////////////////////////

                // Reply with echo
                byte[] echoBuffer = Encoding.ASCII.GetBytes("Echo... " + text);
                clientSocket.Send(echoBuffer);

                // Starts receiving data again
                clientSocket.BeginReceive(rcvBuffer, 0, rcvBuffer.Length, SocketFlags.None, ReceiveCallback, null);
            }
            catch (Exception ex) { AppendToTextBox("Exception: " + ex.Message + "..."); }
        }

        // Provides a thread-safe way to append text to the textbox
        void AppendToTextBox(string text)
        {
            MethodInvoker invoker = new MethodInvoker(delegate
            {
                textBox.Text += text + "\r\n\r\n";
                textBox.SelectionStart = textBox.TextLength;
                textBox.ScrollToCaret();

            }); // "\r\n" are for new lines
            this.Invoke(invoker);
        }
}

Try this: http://stackoverflow.com/questions/19218589/tcp-server-with-multiple-clients — Jane S, May 07 '14 at 05:54
Or this: http://stackoverflow.com/questions/7104293/best-way-to-accept-multiple-tcp-clients — Jane S, May 07 '14 at 05:55

Tyler Gregorcyk · Answer 1 · 2016-04-13T00:33:46.297

To allow the server and client to be on two different machines you need to change the clientSocket.Connect(new IPEndPoint(IPAddress.Loopback, PORT)); to

IPAddress ipAd = IPAddress.Parse(YOUR IP HERE);
clientSocket.Connect(ipAd, YOUR PORT HERE);

Also ive made a simple client in my library if you want to check it out: https://github.com/TheRealNOIG/TylerGregorcyksLibrary/blob/master/TylerGregorcyksLibrary/Main/SimpleClient.cs

Now making a server that can handle multiple clients is a little harder but lucky for I've made a example

class Server
{
    private static int bufferSize = 2048;
    private static byte[] buffer = new byte[bufferSize];
    private static List<Socket> clientSockets = new List<Socket>();
    private static Socket serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);


    static void Main(string[] args)
    {
        Console.Title = "Server";
        SetupServer();
        Console.ReadKey();
        CloseAllSockets();
    }

    private static void SetupServer()
    {
        Console.WriteLine("Settings Up Server Plz Wait");
        serverSocket.Bind(new IPEndPoint(IPAddress.Any, YOUR PORT HERE));
        serverSocket.Listen(10);
        serverSocket.BeginAccept(new AsyncCallback(CallBack), null);
        Console.WriteLine("Server Made");
    }

    private static void CallBack(IAsyncResult e)
    {
        try
        {
            Socket socket = serverSocket.EndAccept(e);
            clientSockets.Add(socket);
            Console.WriteLine("Client Connected");
            socket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, new AsyncCallback(ReceiveCallBack), socket);
            serverSocket.BeginAccept(new AsyncCallback(CallBack), null);
        }
        catch (Exception ex) { Console.WriteLine(ex.Message); }
    }

    private static void ReceiveCallBack(IAsyncResult e)
    {
        try
        {
            Socket socket = (Socket)e.AsyncState;
            int received;
            try
            {
                received = socket.EndReceive(e);
            }
            catch (SocketException)
            {
                Console.WriteLine("Client forcefully disconnected");
                socket.Close();
                clientSockets.Remove(socket);
                return;
            }
            byte[] dataBuf = new byte[received];
            Array.Copy(buffer, dataBuf, received);

            string text = Encoding.ASCII.GetString(dataBuf);
            Console.WriteLine("Client request: " + text);

            string response = string.Empty;


            try
            {
                if (command.ToLower() == "What Time is it")
                {
                    response = DateTime.Now.ToString();
                }
                else if (command.ToLower() == "Whats your name")
                {
                    response = "Tyler Gregorcyk";
                }
                else
                {
                    response = "Invaled";
                }
            }
            catch (Exception et) { Console.WriteLine(et.Message); socket.Close(); clientSockets.Remove(socket); }


            if(response == string.Empty)
            {
                response = "Invaled";
            }

            if (response != string.Empty)
            {
                Console.WriteLine("Sent To Client: " + response);
                byte[] data = Encoding.ASCII.GetBytes(response);
                socket.Send(data);
                serverSocket.BeginAccept(new AsyncCallback(CallBack), null);
            }

            conn.Close();
            socket.BeginReceive(buffer, 0, bufferSize, SocketFlags.None, ReceiveCallBack, socket);
        }
        catch (Exception) { }
    }

    private static void CloseAllSockets()
    {
        foreach (Socket socket in clientSockets)
        {
            socket.Shutdown(SocketShutdown.Both);
            socket.Close();
        }

        serverSocket.Close();
    }
}

BTW this is a edited version of a tutorial on YouTube: https://www.youtube.com/watch?v=xgLRe7QV6QI

Clien-Server to run on different machines and multiple clients

1 Answers1