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Winsock server/client application in c#

I'm working to make a Client/Server Application in C# using winsock Control. I done every thing in that but i stuck the place of sending data from client to server. In my program server always listen the client using the ip and port. I send the data from the client to server.
1)When click the Listen button on the server form it open the server where client is connect.
2)In Client form 1st i click the connect button for that the server is connected Gives an message (Connect Event: ip) for this message we easly know that the client is connected to the server.
3)Then we enter some data in the Send Data text Box then click Send Button to send the data to server and also save in client.
Code Below:
SERVER:
using System;
using System.Collections.Generic;
using System.Windows.Forms;
using System.Net;
using System.Threading;
using System.Net.Sockets;
namespace Server
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
const string DEFAULT_SERVER = "ip";
const int DEFAULT_PORT = 120;
System.Net.Sockets.Socket serverSocket;
System.Net.Sockets.SocketInformation serverSocketInfo;
public string Startup()
{
IPHostEntry hostInfo = Dns.GetHostByName(DEFAULT_SERVER);
IPAddress serverAddr = hostInfo.AddressList[0];
var serverEndPoint = new IPEndPoint(serverAddr, DEFAULT_PORT);
serverSocket = new System.Net.Sockets.Socket(System.Net.Sockets.AddressFamily.InterNetwork, System.Net.Sockets.SocketType.Stream, System.Net.Sockets.ProtocolType.Tcp);
serverSocket.Bind(serverEndPoint);
return serverSocket.LocalEndPoint.ToString();
}
public string Listen()
{
int backlog = 0;
try
{
serverSocket.Listen(backlog);
return "Server listening";
}
catch (Exception ex)
{
return "Failed to listen" + ex.ToString();
}
}
public string ReceiveData()
{
System.Net.Sockets.Socket receiveSocket;
byte[] buffer = new byte[256];
receiveSocket = serverSocket.Accept();
var bytesrecd = receiveSocket.Receive(buffer);
receiveSocket.Close();
System.Text.Encoding encoding = System.Text.Encoding.UTF8;
return encoding.GetString(buffer);
}
private void Listen_Click(object sender, EventArgs e)
{
string serverInfo = Startup();
textBox1.Text = "Server started at:" + serverInfo;
serverInfo = Listen();
textBox1.Text = serverInfo;
//string datatosend = Console.ReadLine();
//SendData(datatosend);
serverInfo = ReceiveData();
textBox1.Text = serverInfo;
//Console.ReadLine();
}
private void winsock_DataArrival(object sender, AxMSWinsockLib.DMSWinsockControlEvents_DataArrivalEvent e)
{
ReceiveData();
Listen();
}
private void winsock_ConnectEvent(object sender, EventArgs e)
{
Listen();
}
}
}
This all are work perfectly But here my problem is that i get data form the client to server at only one time. When i send data again from the client to the server its not working and gives me some Message like
Additional information: Only one usage of each socket address
(protocol/network address/port) is normally permitted
In the server form
serverSocket.Bind(serverEndPoint);
Please someone help me to solve my problem.
Thank you.

Try this. It helps you
delegate void AddTextCallback(string text);
public Form1()
{
InitializeComponent();
}
private void ButtonConnected_Click(object sender, EventArgs e)
{
ThreadPool.QueueUserWorkItem(new WaitCallback(ServerHandler));
}
private void ServerHandler(object state)
{
TcpListener _listner = new TcpListener(IPAddress.Parse("12.2.54.658"), 145);
_listner.Start();
AddText("Server started - Listening on port 145");
Socket _sock = _listner.AcceptSocket();
//AddText("User from IP " + _sock.RemoteEndPoint);
while (_sock.Connected)
{
byte[] _Buffer = new byte[1024];
int _DataReceived = _sock.Receive(_Buffer);
if (_DataReceived == 0)
{
break;
}
AddText("Message Received...");
string _Message = Encoding.ASCII.GetString(_Buffer);
AddText(_Message);
}
_sock.Close();
AddText("Client Disconnected.");
_listner.Stop();
AddText("Server Stop.");
}
private void AddText(string text)
{
if (this.listBox1.InvokeRequired)
{
AddTextCallback d = new AddTextCallback(AddText);
this.Invoke(d, new object[] { text });
}
else
{
this.listBox1.Items.Add(text);
}
}
I'm also have the same problem like you on last month but i solve that using this Receive multiple different messages TcpListener C# from stackoverflow. This helps me lot hope it helps to solve your problem also.

I'm not 100% sure you understand TCP sockets so here goes.
When you use a TCP listener socket you first bind to a port so that clients have a fixed, known point to connect to. This reserves the port for your socket until you give it up by calling Close() on that socket.
Next you Listen in order to begin the process of accepting clients on the port you bound to. You can do both this and the first step in one but as you haven't I haven't here.
Next you call Accept(). This blocks (halts execution) until a client connects and then it returns a socket which is dedicated to communication with that client. If you want to allow another client to connect, you have to call Accept() again.
You can then communicate with your client using the socket that was returned by Accept() until you're done, at which point you call Close() on that socket.
When you're done listening for new connections you call Close() on your listener socket.
However when you press your listen button the following happens:
You bind correctly, you begin listening correctly and then your call to ReceiveData() blocks on the Accept call until a client is received. You then receive some data (though this is TCP so that might not be the whole data!) and then you instantly close the connection to your client.
I presume to get the error you're getting you must then press listen again on your server. This therefore restarts the whole listener socket and when you get to bind to the port the second time your previous listener is still bound to it and thus the call fails because something's already allocated on that port.
Solution wise you need to keep the socket returned from the Accept() call open until you're done with it. Have the client handle the close by calling the Shutdown() method on their socket or establish some convention for marking the end of communication.
You're also going to run into trouble when you try and have multiple users connected and so at some point you're either going to require threads or some asynchronous sockets but I feel that's out the scope of this question.

I suggest you do not use AxMSWinsockLib.. Have a look at socket example given here where it shows how to create a client socket and server socket - https://msdn.microsoft.com/en-us/library/kb5kfec7(v=vs.110).aspx AND this one - https://msdn.microsoft.com/en-us/library/6y0e13d3(v=vs.110).aspx

Can't establish connection using StreamSocket (universal windows)

Im trying to follow this code sample from microsoft, who is a basic code for sending/receiving data over network from windows 10 computer/phone.
Im on VS2015, i have a phone on W10 and my computer also.
The problem is that my application seems to create packet and send one to establish the connection (i have seen this packet with wireshark), but i never received it on the server side.
Here is code to listen port from the actual internet connection available and wait for a connection :
public static async void StartServer()
{
try
{
StreamSocketListener listener = new StreamSocketListener();
//ConnectionProfile internetConnectionProfile = NetworkInformation.GetInternetConnectionProfile();
//await listener.BindServiceNameAsync("5043", SocketProtectionLevel.PlainSocket, internetConnectionProfile.NetworkAdapter);
listener.ConnectionReceived += OnConnection;
await listener.BindServiceNameAsync("5043");
Debug.WriteLine("Server Started !");
}
catch (Exception)
{
Debug.WriteLine("Error StartServer Method !");
}
}
The method "OnConnection" is never reach cause the event "ConnectionReceived" is never called.
Here is the code to establish connection (the string ipDestination contain the internet ip address from my phone for example, that i get from checkip.dyndns.org) :
private static StreamSocket socket;
public static async void Connect(string ipDestination)
{
try
{
//Destination Ip address
HostName host = new HostName(ipDestination);
ConnectionProfile internetConnectionProfile = NetworkInformation.GetInternetConnectionProfile();
socket = new StreamSocket();
socket.Control.KeepAlive = true;
await socket.ConnectAsync(host, "5043");
//EXCEPTION RAISE HERE after a moment "System.Runtime.InteropServices.COMException, cant join destination.
Debug.WriteLine("Connected !");
}
catch (Exception)
{
Debug.WriteLine("Erreur Connect Method !");
}
}
I think i should miss something but i dont know why and im block at this part since a long and can't continue my project...
I apologize for the bad english I try to make my best :)
Update from comments :
As Jay Zuo suggested, i have try to use local address on private
network and it works, i can establish connection, send and receive
data without problems... So the problem come when i use internet IP
address, and i still can't figure why...
As Kiewic suggested, i have simplify my code and commented the
precedent version.

Client Bluetooth connection with 32feet.NET fails all the time

I'm trying to get a Bluetooth socket connection up and running but for some reason my client will not connect.
More precisely I get an exception when I try to connect to the stream:
A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.
All examples I found online didn't really solve my problem and I'm currently not really sure where the problem comes from.
The scanning and pairing works fine - I see that the Bluetooth device in question gets successfully paired.
I try to connect via first setting the Client and then call connect
Client Bluetooth name, address and pin are known:
public bool SetClient(String clientName, String btAddress, String pin)
{
bool retVal = false;
m_remoteBluetoothClient = new BluetoothDeviceInfo(BluetoothAddress.Parse(btAddress));
m_localBluetoothClient.SetPin(pin);
if (m_remoteBluetoothClient.Authenticated)
{
//m_localBluetoothClient.Authenticate = true;
retVal = true;
}
else
{
if (BluetoothSecurity.PairRequest(m_remoteBluetoothClient.DeviceAddress, pin))
{
retVal = true;
}
}
return retVal;
}
Then an async connect:
private void ClientConnectThread()
{
m_localBluetoothClient.BeginConnect(m_remoteBluetoothClient.DeviceAddress, BluetoothService.SerialPort, Connect, m_localBluetoothClient);
}
private void Connect(IAsyncResult result)
{
if (result.IsCompleted)
{
m_localBluetoothClient.EndConnect(result);
mBtStream = m_localBluetoothClient.GetStream();
}
}
The locals m_localBluetoothEndpoint and m_localBluetoothClient are created like this although the Endpoint is more or less new (before I used BluetoothCLient without parameter):
m_localBluetoothEndpoint = new BluetoothEndPoint(BluetoothRadio.PrimaryRadio.LocalAddress, BluetoothService.SerialPort);
m_localBluetoothClient = new BluetoothClient(m_localBluetoothEndpoint);
I also tried to work with a Listener in case the remote devices wants to connect but the callback gets never called:
public void SetupListener()
{
var listener = new BluetoothListener(BluetoothService.SerialPort);
listener.Start();
listener.BeginAcceptBluetoothClient(this.BluetoothListenerAcceptClientCallbackTwo, listener);
}
Can anyone tell me if there is anything wrong with my connection approach above and how I can figure out why I get the exception mentioned above?
The exception gets thrown here:
m_localBluetoothClient.EndConnect(result);
A thing I also don't understand is that the SupportedServices call to the remoteCLient returned 0 guids - so the device did not list any Bluetooth services.
m_remoteBluetoothClient.InstalledServices()
Thank you

Client disconnected on receiving message from other client

I am working on Lan based interoffice messaging system.
The steps in my applications are :
Server starts and listen for clients
Clients on connection gets the view of all the other connected clients.
On connection to the server i do check in the database that if that client is authorize or not.
if i dont check in the database on client connection to the server then the application does work normally other wise the client if not exists in the database the the client application got closed.
the related code is here :
public void CheckUserName(string userName)
{
if (userName != "Usman") // checking in database( a static name)
{
//Check if the username is registered
Send("sorry#Invalid Username, try another Username!!");
Disconnect();
return;
}
else
{
//If name is not duplicate then the client is connected
this.connected =true;
this.userName =userName;
//Build the Usernames list and send it to the client
StringBuilder userList = new StringBuilder();
userList.Append(this.clientID);
Hashtable clientTable =ClientList.GetList;
foreach(DictionaryEntry d in clientTable)
{
//Seperate the usernames by a '#'
userList.Append("#");
userList.Append(d.Value.ToString());
}
//Start the llistening
lock(myClient.GetStream())
{
AsyncCallback GetStreamMsgCallback = new AsyncCallback(GetStreamMsg);
myClient.GetStream().BeginRead(recByte,0,1024,GetStreamMsgCallback,null);
}
//Send the Userlist
Send(userList.ToString());
//Raise the Connected Event
if(Connected!=null)
{
EventArgs e = new EventArgs();
Connected(this, e);
}
}
}
Do anyone could suggest that what to do to get rid of this bad thing?

Have you considered initially querying the database for all enabled users when the server starts then caching those results? this way you can avoid having to query on every user connection. You can store the entitled users in a Dictionary or some other style of lookup table.

Unable to read data from the transport connection: the connection was closed

The exception is Remoting Exception - Authentication Failure. The detailed message says "Unable to read data from the transport connection: the connection was closed."
I'm having trouble with creating two simple servers that can comunicate as remote objects in C#. ServerInfo is just a class I created that holds the IP and Port and can give back the address. It works fine, as I used it before, and I've debugged it. Also the server is starting just fine, no exception is thrown, and the channel is registered without problems. I'm using Forms to do the interfaces, and call some of the methods on the server, but didn't find any problems in passing the parameters from the FormsApplication to the server when debugging. All seems fine in that chapter.
public ChordServerProgram()
{
RemotingServices.Marshal(this, "PADIBook");
nodeInt = 0;
}
public void startServer()
{
try
{
serverChannel = new TcpChannel(serverInfo.Port);
ChannelServices.RegisterChannel(serverChannel, true);
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
I run two instances of this program. Then startNode is called on one of the instances of the application. The port is fine, the address generated is fine as well. As you can see, I'm using the IP for localhost, since this server is just for testing purposes.
public void startNode(String portStr)
{
IPAddress address = IPAddress.Parse("127.0.0.1");
Int32 port = Int32.Parse(portStr);
serverInfo = new ServerInfo(address, port);
startServer();
//node = new ChordNode(serverInfo,this);
}
Then, in the other istance, through the interface again, I call another startNode method, giving it a seed server to get information from. This is where it goes wrong. When it calls the method on the seedServer proxy it just got, a RemotingException is thrown, due to an authentication failure. (The parameter I'll want to get is the node, I'm just using the int to make sure the ChordNode class has nothing to do with this error.)
public void startNode(String portStr, String seedStr)
{
IPAddress address = IPAddress.Parse("127.0.0.1");
Int32 port = Int32.Parse(portStr);
serverInfo = new ServerInfo(address, port);
IPAddress addressSeed = IPAddress.Parse("127.0.0.1");
Int32 portSeed = Int32.Parse(seedStr);
ServerInfo seedInfo = new ServerInfo(addressSeed, portSeed);
startServer();
ChordServerProgram seedServer = (ChordServerProgram)Activator.GetObject(typeof(ChordServerProgram), seedInfo.GetFullAddress());
// node = new ChordNode(serverInfo,this);
int seedNode = seedServer.nodeInt;
// node.chordJoin(seedNode.self);
}

Try setting the ensureSecurity to false, and it should start working.
ChannelServices.RegisterChannel(serverChannel, false);

You've specified that security is a must on your Remoting server in startServer() with:
ChannelServices.RegisterChannel(serverChannel, true);
Yet the 'client' end does not specify security, hence the authorisation error. You need to specify tcp channel security on both ends unless the server security setting is set to 'false'. In your second startNode method you need to do the following before using Activator.GetObject, note no port specified on the TcpChannel unlike the server end:
TcpChannel ClientChan = new TcpChannel();
ChannelServices.RegisterChannel(ClientChan, true);
Furthermore, unless you're doing it in some code you haven't given us, you also do not seem to have registered a well known service type server side, although you say it's been working in the debugger so maybe that's not necessary in the case. See MSDN on RegisterWellKnownServiceType.