C# TCP Application won't work - c#

I'm making a simple chat application using TcpClient and TcpServer from System.Net.
I got everything working on my PC, the server communicates with the client and vice versa. But when I try to connect to the same server application using another PC (even on the same subnet as my PC) the thing doesn't work.
I've tried port-forwarding through my router, firewall and still nothing.
The Can you see me website says that the connection is being refused. Although!! Sometimes it says that the connection is timed out completely.
I am not sure what's wrong with my code or my PC, I would really appreciate some help from people that are more experienced in this area than I am.
Here is the configuration for the port forwarding in my router:
If you need the code for the client and the server, here they are:
P.S. I make the change to the client in the BeginConnect() part at the bottom in order to change the IP address that I'm connecting to
Client:
using System;
using System.Text;
using System.Windows.Forms;
using System.Net.Sockets;
using System.Net;
namespace TcpTest_Client_
{
public partial class Form1 : Form
{
TcpClient client;
IPAddress localIP = null;
bool connected = false;
public Form1()
{
InitializeComponent();
}
public void clientConnectCallback(IAsyncResult result)
{
try
{
client.EndConnect(result);
Log("Connected to " + client.Client.RemoteEndPoint);
connected = true;
NetworkStream clientStream = client.GetStream();
byte[] message = new byte[4096];
int bytesRead;
while (true)
{
bytesRead = 0;
try
{
//blocks until a client sends a message
bytesRead = clientStream.Read(message, 0, 4096);
}
catch (Exception ex)
{
//a socket error has occured
Log(ex.Message);
break;
}
if (bytesRead == 0)
{
//the client has disconnected from the server
Log("Server on has disconnected");
break;
}
//message has successfully been received
UTF8Encoding encoder = new UTF8Encoding();
string bufferincmessage = encoder.GetString(message, 0, bytesRead);
Log("Server: " + bufferincmessage);
}
}
catch (Exception ex)
{
Log(ex.Message);
}
}
public void Log(string msg)
{
richTextBox1.BeginInvoke(new Action(
() =>
{
richTextBox1.Text += msg + "\n";
}));
}
private void Form1_Load(object sender, EventArgs e)
{
foreach (IPAddress addr in Dns.GetHostAddresses(Dns.GetHostName()))
{
if (addr.AddressFamily == AddressFamily.InterNetwork)
{
localIP = addr;
break;
}
}
client = new TcpClient(AddressFamily.InterNetwork);
}
private void button2_Click(object sender, EventArgs e)
{
try
{
client.BeginConnect(IPAddress.Parse("109.252.107.144"), 1234, clientConnectCallback, client);
}
catch (Exception ex)
{
Log(ex.Message);
}
}
private void button1_Click(object sender, EventArgs e)
{
if (connected)
{
UTF8Encoding encoder = new UTF8Encoding();
NetworkStream clientStream = client.GetStream();
byte[] stringToSend = new byte[richTextBox2.Text.Length];
stringToSend = encoder.GetBytes(richTextBox2.Text);
clientStream.Write(stringToSend, 0, stringToSend.Length);
}
}
}
}
Server:
using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;
using System.Net;
using System.Net.Sockets;
using System.Threading;
namespace TcpTest
{
public partial class Form1 : Form
{
private TcpListener server;
private List<Thread> clientThreads = null;
public Thread MainThread;
public Form1()
{
InitializeComponent();
}
public void Log(string msg)
{
richTextBox1.BeginInvoke(new Action(
() =>
{
richTextBox1.Text += msg + "\n";
}));
}
public static string bufferincmessage;
public void AcceptSocketPackets(object client)
{
TcpClient tcpClient = (TcpClient)client;
NetworkStream clientStream = tcpClient.GetStream();
byte[] message = new byte[4096];
int bytesRead;
while (true)
{
bytesRead = 0;
try
{
//blocks until a client sends a message
bytesRead = clientStream.Read(message, 0, 4096);
}
catch (Exception ex)
{
//a socket error has occured
Log(ex.Message);
break;
}
if (bytesRead == 0)
{
//the client has disconnected from the server
Log("Client on " + tcpClient.Client.RemoteEndPoint + " has disconnected from the server");
break;
}
//message has successfully been received
UTF8Encoding encoder = new UTF8Encoding();
bufferincmessage = encoder.GetString(message, 0, bytesRead);
Log("Client from " + tcpClient.Client.RemoteEndPoint + ": " + bufferincmessage);
string stringToSend = "You sent me: " + bufferincmessage;
byte[] messageToSend = new byte[stringToSend.Length];
messageToSend = encoder.GetBytes(stringToSend);
clientStream.Write(messageToSend, 0, messageToSend.Length);
}
}
public void SocketAcceptCallback(IAsyncResult result)
{
TcpClient newClient = server.EndAcceptTcpClient(result);
Log("Accepted client on " + newClient.Client.RemoteEndPoint);
clientThreads.Add(new Thread(new ParameterizedThreadStart(AcceptSocketPackets)));
clientThreads[clientThreads.Count - 1].Start(newClient);
server.BeginAcceptTcpClient(SocketAcceptCallback, server);
}
private void Form1_Load(object sender, EventArgs e)
{
MainThread = Thread.CurrentThread;
clientThreads = new List<Thread>();
try
{
IPAddress localIP = null;
foreach (IPAddress addr in Dns.GetHostAddresses(Dns.GetHostName()))
{
if (addr.AddressFamily == AddressFamily.InterNetwork)
{
localIP = addr;
break;
}
}
localIP = IPAddress.Any;
// could also use this:
// server = new TcpListener(new IPEndPoint(IPAddress.Any, 1234));
server = new TcpListener(new IPEndPoint(localIP, 1234));
Log("Starting server on " + localIP + ":1234");
server.Start(6);
server.BeginAcceptTcpClient(SocketAcceptCallback, server);
Log("Started server on " + localIP + ":1234");
}
catch (Exception ex)
{
Log(ex.Message);
}
}
}
}

C++ is giving me problems like that. Try creating another project, paste the server code and build it as Release x86. If you change the build target and our problem is the same, windows firewall, even when turned off, won't allow the server or the client to run without any exception. If it doesn't work I might not know the answer.

Related

check when a client is disconnected

I have a console application in c#
this code can tell me when a client si connected in TCP to port 3001 and the message sent
I cant understand when he disconnects, its going into while (client.Connected) unlimited, i tried to check with a PING but sometimes returns false even if connnected,
I am stuck
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Net.Sockets;
namespace ConsoleApp2
{
class Program
{
static void Main(string[] args)
{
int port = 3001;
TcpListener listener = new TcpListener(IPAddress.Any, port);
listener.Start();
Console.WriteLine("Listening on port " + port + "...");
while (true)
{
TcpClient client = listener.AcceptTcpClient();
Console.WriteLine("Accepted connection from " + client.Client.RemoteEndPoint.ToString());
while (client.Connected)
{
NetworkStream stream = client.GetStream();
if (stream.DataAvailable)
{
byte[] buffer = new byte[1024];
int bytesRead = stream.Read(buffer, 0, buffer.Length);
string data = Encoding.UTF8.GetString(buffer, 0, bytesRead);
Console.WriteLine("Received data: " + data);
}
//check if client still connected
string[] cli = client.Client.RemoteEndPoint.ToString().Split(Convert.ToChar(":"));
string Host = cli[0];
int Uri = port;// int.Parse(cli[1]);
if (PingHost(Host,Uri)==false)
{
Console.WriteLine("Client disconnected.");
break;
}
}
}
}
public static bool PingHost(string hostUri, int portNumber)
{
try
{
using (var client = new TcpClient(hostUri, portNumber))
return true;
}
catch (SocketException ex)
{
//MessageBox.Show("Error pinging host:'" + hostUri + ":" + portNumber.ToString() + "'");
return false;
}
}
}
}

C# create multi threaded socket server and select client/connection

Currently, I'm programming in C#, I would like to modify the code below to isolate one client connection. so like creating a break-out room from the main pool.
Below are 2 files, one is just the basic standard .NET Framework Console App Program.cs file; the other is the server file. Combined, they both can make a multi-threaded server, but I would like one that allows me to also select a client to connect to in case if I were to create a remote control application as my friend did.
On a side note, I would like to share that I want to be able to connect to a client by entering connect [1,2,3,etc..] into the console.
Answers
If you answer, please put some code, It would really, really help. I learn a lot better by looking att the code rather than reading documentation.
Code
Server.cs
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
namespace TCPServer
{
class Server
{
TcpListener server = null;
int counter = 0;
public Server(string ip, int port)
{
IPAddress localAddr = IPAddress.Parse(ip);
server = new TcpListener(localAddr, port);
server.Start();
StartListener();
}
public void StartListener()
{
try
{
while (true)
{
Console.WriteLine("Waiting for incoming connections...");
TcpClient client = server.AcceptTcpClient();
counter += 1;
Console.WriteLine("Connected to authorized client: {0}", counter);
Thread t = new Thread(new ParameterizedThreadStart(HandleDeivce));
t.Start(client);
}
}
catch (SocketException e)
{
Console.WriteLine("SocketException: {0}", e);
server.Stop();
}
}
public void HandleDeivce(Object obj)
{
TcpClient client = (TcpClient)obj;
var stream = client.GetStream();
string imei = String.Empty;
string data = null;
Byte[] bytes = new Byte[256];
int i;
try
{
while ((i = stream.Read(bytes, 0, bytes.Length)) != 0)
{
string hex = BitConverter.ToString(bytes);
data = Encoding.ASCII.GetString(bytes, 0, i);
Console.WriteLine("{1}: Received: {0}", data, Thread.CurrentThread.ManagedThreadId);
if (data != "auth token")
{
stream.Close();
client.Close();
}
string str = "Device authorization successfull";
Byte[] reply = System.Text.Encoding.ASCII.GetBytes(str);
stream.Write(reply, 0, reply.Length);
Console.WriteLine("{1}: Sent: {0}", str, Thread.CurrentThread.ManagedThreadId);
}
}
catch (Exception e)
{
Console.WriteLine("Exception: {0}", e.ToString());
client.Close();
}
}
}
}
Program.cs
using System;
using System.Threading;
namespace TCPServer
{
class Program
{
static void Main(string[] args)
{
Thread thread = new Thread(delegate()
{
Server server = new Server("127.0.0.1", 13000);
});
thread.Start();
Console.WriteLine("Server started...");
}
}
}

How to add multiple clients to a server in c#?

My Client Source Code :
public partial class Form1 : Form
{
string serverip = "localHost";
int port = 160;
public Form1()
{
InitializeComponent();
}
private void Submit_Click(object sender, EventArgs e)
{
TcpClient client = new TcpClient(serverip, port);
int byteCount = Encoding.ASCII.GetByteCount(Message.Text);
byte[] sendData = new byte[byteCount];
sendData = Encoding.ASCII.GetBytes(Message.Text);
NetworkStream stream = client.GetStream();
stream.Write(sendData, 0, sendData.Length);
stream.Close();
client.Close();
}
private void Form1_Load(object sender, EventArgs e)
{
}
}
My server
class Program
{
static void Main(string[] args)
{
IPAddress ip = Dns.GetHostEntry("localHost").AddressList[0];
TcpListener server = new TcpListener(ip, 160);
TcpClient client = default(TcpClient);
try
{
server.Start();
Console.WriteLine("The server has started successfully");
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
Console.ReadLine();
}
while (true)
{
client = server.AcceptTcpClient();
byte[] receivedBuffer = new byte[100];
NetworkStream stream = client.GetStream();
stream.Read(receivedBuffer, 0, receivedBuffer.Length);
StringBuilder msg = new StringBuilder();
foreach (byte b in receivedBuffer)
{
if (b.Equals(59))
{
break;
}
else
{
msg.Append(Convert.ToChar(b).ToString());
}
}
Console.WriteLine(msg.ToString() + msg.Length);
}
}
}
Essentially i want make it so i can have multiple clients on the server sending a message from different ip addresses of course. I have been using c# a year now mostly in school and I am above average at best at it.
First time asking question so sorry if its in wrong format

TCP Service & REST APIs

I have a GPS Tracker Device, I have run a TCP/IP Server Code which Successfully establishes connection with each device in a separate Thread and Device Keep sending its heart beat after one minute and server replies ON. When I send a command to get device location it gives me location and everything is working fine.
Now I want to get location from an android device using web service, Now I'm confuse how can I use running thread of a specific device from an Android App?
class Server
{
TcpListener server = null;
public Server(string ip, int port)
{
IPAddress localAddr = IPAddress.Parse(ip);
server = new TcpListener(localAddr, port);
server.Start();
StartListener();
}
public void StartListener()
{
try
{
while (true)
{
Console.WriteLine("Waiting for a connection... ");
TcpClient client = server.AcceptTcpClient();
Console.WriteLine("Connected!");
Thread t = new Thread(new ParameterizedThreadStart(HandleDeivce));
t.Start(client);
}
}
catch (SocketException e)
{
Console.WriteLine("SocketException: {0}", e);
}
}
public void HandleDeivce(Object obj)
{
TcpClient client = (TcpClient)obj;
NetworkStream stream = client.GetStream();
string data = null;
Byte[] bytes = new Byte[256];
int i;
while ((i = stream.Read(bytes, 0, bytes.Length)) != 0)
{
data = Encoding.ASCII.GetString(bytes, 0, i);
Console.WriteLine("{1}: Received: {0}", data, Thread.CurrentThread.ManagedThreadId);
if (data.StartsWith("##"))
{
data = "LOAD";
}
else
{
data = "ON";
}
byte[] msg = Encoding.ASCII.GetBytes(data);
stream.Write(msg, 0, msg.Length);
Console.WriteLine("{1}: Sent: {0}", data, Thread.CurrentThread.ManagedThreadId);
}
client.Close();
}
}
Try making code look like this
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Xml.Linq;
using System.Net;
using System.Net.Sockets;
using System.Threading;
namespace ConsoleApplication16
{
class Program
{
const string IP = "123.456.789.000";
const int PORT_NUMBER = 1234;
static AutoResetEvent autoEvent = new AutoResetEvent(false);
static void Main(string[] args)
{
GPSClient client = new GPSClient(IP, PORT_NUMBER);
//start http client or equivalent here
while (true)
{
autoEvent.Reset();
autoEvent.WaitOne();
//wait for message from user/client on service port
string message = client.message;
//send message back to user/client
}
}
}
public class WebServer
{
}
public class GPSClient
{
const int BUFFER_SIZE = 256;
TcpClient client = null;
NetworkStream stream = null;
Byte[] bytes = new Byte[BUFFER_SIZE];
public string message { get; set; }
public GPSClient(string ip, int port)
{
try
{
Console.WriteLine("Connecting to Device... ");
client.Connect(ip, port);
Console.WriteLine("Connected!");
stream = client.GetStream();
stream.BeginRead(bytes, 0, BUFFER_SIZE, new AsyncCallback(HandleDeivce), stream);
}
catch (SocketException e)
{
Console.WriteLine("SocketException: {0}", e);
}
}
public void HandleDeivce(IAsyncResult ar)
{
NetworkStream stream = ar.AsyncState as NetworkStream;
string data = null;
int i = stream.Read(bytes, 0, BUFFER_SIZE);
data = Encoding.ASCII.GetString(bytes, 0, i);
Console.WriteLine("Received: {0}", data);
message = data;
if (data.StartsWith("##"))
{
data = "LOAD";
}
else
{
data = "ON";
}
byte[] msg = Encoding.ASCII.GetBytes(data);
stream.Write(msg, 0, msg.Length);
Console.WriteLine("Sent: {0}", data);
stream.BeginRead(bytes, 0, BUFFER_SIZE, new AsyncCallback(HandleDeivce), stream);
}
}
}

send data to any connected client

I have created server application to accept connection from clients. After client connected to server ... they can send data and receive data between each other , but when another client is connected ... the server can not send data to frist client connected .
I need help how to save connected client on this server ... and how to send data to specified client.
The server class is :
namespace WindowsApplication11
{
public partial class Form1 : Form
{
private TcpListener tcpListener;
private Thread listenThread;
public Form1()
{
InitializeComponent();
}
TcpListener myList;
private void Form1_Load(object sender, EventArgs e)
{
try
{
myList = new TcpListener(IPAddress.Any, 8001);
/* Start Listeneting at the specified port */
myList.Start();
while (true)
{
TcpClient client = myList.AcceptTcpClient();
saveclient(" Client " + client.Client.RemoteEndPoint.ToString());
// - receive msg from client -
byte[] bb = new byte[10000];
int kb = client.Client.Receive(bb);
string stringu = "";
for (int i = 0; i < kb; i++)
stringu += Convert.ToChar(bb[i]);
// - send msg to accepted client -
Byte[] datat = System.Text.Encoding.ASCII.GetBytes("nje-> " + stringu);
NetworkStream stream = client.GetStream();
stream.Write(datat, 0, datat.Length);
stream.Flush();
}
}
catch (Exception ea)
{
Console.WriteLine("Error..... " + ea.Message);
}
}
void saveclient(string idlidhje)
{
try
{
System.IO.StreamWriter stw = System.IO.File.AppendText("d:\\clients.txt");
string teksti = System.String.Format("{0:G}: {1}.", System.DateTime.Now, idlidhje);
stw.WriteLine(teksti + "\n");
stw.Close();
}
catch (Exception eks)
{
}
}
}
}
The client class is :
public Form1()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e)
{
IPAddress addr = IPAddress.Any;
byte[] data = new byte[1024];
string input, stringData;
TcpClient server;
try
{
server = new TcpClient("127.0.0.1", 8001);
// - send msg -
Byte[] datat = System.Text.Encoding.ASCII.GetBytes("Hello");
NetworkStream stream = server.GetStream();
stream.Write(datat, 0, datat.Length);
stream.Flush();
// - receive msg -
byte[] bb = new byte[10000];
int kb = server.Client.Receive(bb);
string stringu = "";
for (int i = 0; i < kb; i++)
stringu += Convert.ToChar(bb[i]);
}
catch (SocketException fd)
{
MessageBox.Show("Cannot connect " + fd.Message.ToString());
}
}
Robert answered to a similar question here on SO:
https://stackoverflow.com/a/15878306/17646
Basically you have to keep the connected clients in a list (your TcpClient object 'client' gets lost every time the while loop starts again) and you need threads or async methods to handle the different clients.

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