Click here to Skip to main content
15,891,923 members
Everything / TcpClient

TcpClient

TcpClient

Great Reads

by Espen Harlinn
A .NET Core client implemented in C# using TcpClient and a multi-threaded server implemented in C++
by Sicppy
A DLL resource to help beginner to intermediate developers open and use sockets in a P2P application.
by Nosey Parker
TcpClient.BeginConnect with timeout
by Craig Baird
A light weight easy to use .NET TCP server library

Latest Articles

by Espen Harlinn
A .NET Core client implemented in C# using TcpClient and a multi-threaded server implemented in C++
by MehreenTahir
This article will help you get started with socket programming in C++. We will build a TCP server and client using boost.asio library in C++.
by Nosey Parker
TcpClient.BeginConnect with timeout
by Sicppy
A DLL resource to help beginner to intermediate developers open and use sockets in a P2P application.

All Articles

Sort by Title

TcpClient 

4 Nov 2022 by Member 14623639
I know this is a common question people ask but for days I have been researching and couldn't find a way that will help me. I'm developing a screen sharing program and using TCP to send the desktop screenshots over the networkstream. I tried...
4 Nov 2022 by RickZeeland
Try this CodeProject article: Windows Remote Desktop Application[^] It probably has TCP routines you can use.
4 Nov 2022 by Chris Copeland
In addition to RickZeeland's comment, another important thing to remember when it comes to network/streaming is that there's no guarantee how many bytes you'll receive at any given time. byte[] bytes = new byte[1000000]; ...
19 Dec 2013 by Member 10478484
I'm writing an application that has to make a connection on a socket to a set IP and port. During the lifetime of this socket connection, I'm required to listen on a specific port and respond when a message is received on the same port.The application is part of a complex multi threaded...
19 Dec 2013 by CHill60
Without seeing the actual code it's quite difficult to assist. However will this article help Multi-threaded Client/Server Socket Class[^]?
28 Dec 2013 by Albert Holguin
This sort of sounds like you may be accidentally using the same socket on different ports. Check to make sure each one has his own socket and they're not somehow using the same socket identifier. Also, make sure that your listening thread isn't terminating early for one reason or another.As...
13 May 2015 by Member 11687571
Good day dear programmers , hopefully soon I become a colleague :) . I am just new to programming , but still I have had some experience with programming in Access VB and a a small overview over VB.Net . But let's get to the question . I want to build a nice app with a Server side and...
13 May 2015 by Afzaal Ahmad Zeeshan
A Windows Forms application would be good, but since you're going to allow multiple users to communicate through the same hub (server), ASP.NET would be better. If you do not want to use a website, with a layout and other formalities, ASP.NET Web API[^] would be best for this type of...
29 Jan 2013 by ali_heidari_
hi....i want to make a small app for connecting to a chat application and get some data! i want know is a generl way to connect with any server and get data or any server must provide some ways to let us connect to it! and if a server didnt do that we cant connect to it?i know how i can...
29 Jan 2013 by Marco Bertschi
This tutorial[^] helped me.
30 Jan 2013 by Sergey Alexandrovich Kryukov
First of all, when you talking about "server", it should be something which you develop yourself, because you will need to have some custom application-layer protocol:http://en.wikipedia.org/wiki/Application_layer[^].More exactly, a service. The term "server" is more often used in a narrow...
8 Sep 2020 by Patrice T
Quote: 1. What is the sequence number? 2. What is the destination port number? 3. What is the source port number? 4. What is the length of the TCP header? 5. What is the acknowledgement number? What about doing basic research on internet before...
11 Dec 2013 by Member 10440446
Hi guys, any idea on how am I suppose to create an application on C# 5.0 using async await Telnet client.My scenario is that I have to telnet multiple servers at the same time. Also, i need it to check the servers continuously just like a ping /t function.Thanks much.. :)
12 Dec 2013 by Sergey Alexandrovich Kryukov
Why?! Create a separate thread to work with each separate telnet server and work synchronously. Synchronize those threads using thread synchronization in those rare cases when it is needed.I think asynchronous APIs get popularity when threads were not a commonplace, or just because many...
15 Jul 2014 by Matthew Dennis
// assuming you have created a CancellationToken so you can cancel the Telnet Monitors.List telnetTasks = new List();for (var i = 0; i
12 Aug 2018 by BatLine
I tried turning a console app into an windows form and everything went well until I wanted to make the received message (it's like a chat client) show in a textbox. Client Form: using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using...
12 Aug 2018 by OriginalGriff
Static objects and static methods are special: they are associated with the whole class, not with a single instance of the class - and as such, a static method cannot access any non-static objects in a class because it has no idea which instance it should use! Think of it like this: public...
21 Sep 2017 by Member 3844375
I am new to TCP and I am trying to connect to a machine. I've been given the command to connect to the machine. which is in the form of xml. The port and IP to the machine is also provided, all i have to do is send the command. The documentation stipulates TCP/IP channels are required for...
21 Sep 2017 by RickZeeland
Here is a simple Client - Server example: Introduction to TCP client server in C#[^] Note that you will have to allow your program through Windows firewall. If you need authentication, see this example: Authenticate WebAPIs with Basic and Windows Authentication[^]
4 Aug 2019 by Leonid Kazakov
I create a list of connections using TcpConnectionInformation, after it I find in that list the address which used in my program by the external IP RemoteEndPoint. Which command used to close the found connection? This task is similar to the Russinovich TCPView program. private void...
4 Aug 2019 by Leonid Kazakov
First of all visit CurrPorts: Monitoring TCP/IP network connections on Windows and download programm CurrPorts. It seems that C # cannot solve the problem of closing the port. We will use the utility: private void ClearConnection() { string programma = Directory.GetCurrentDirectory() +...
8 Apr 2013 by Craig Baird
A light weight easy to use .NET TCP server library
25 Oct 2015 by MrXccv
I am trying to connect to a Cisco router via telnet but i don't need to log in only to get the banner (banner = information the router presents before you get into username & password input))Banner Example:*Welcome To 101044555@xxxxxxx *----------------------------- **ADSL Line :...
25 Oct 2015 by George Jonsson
Try using NetworkStream[^] instead of StreamReader and StreamWriterHave a look at this example.TcpClient.GetStream Method[^]
12 Jan 2018 by Member 13479861
Hi, I am testing a Tcp client C# windows form application I am able to send data to Tcp server Software(Hercules 3.2.8) But when i sent data from Tcp server to windows form then i am getting the following error: System.InvalidOperationException: Cross-Thread operation not valid: Control...
12 Jan 2018 by OriginalGriff
You cannot access any UI control from any thread other than the one it was created on: the UI thread (which is the only one running at the start of your app). If you try, you get a Cross-threading exception as you have seen. If you look at the documentation: Socket.BeginReceiveFrom Method...
5 Nov 2012 by m.bleimuth
Hi,i am trying to write some kind of a simple information System. My Server is written in c#, it sends every minutes udp heartbeats with Server Information (ip, port of the Server). Now i want to write a simple Website with html and JavaScript that connects to my Server and receives data...
5 Nov 2012 by CafedeJamaica
You can set up a TCPListener depending, if you google the class there is a very straght forwad example.http://msdn.microsoft.com/en-us/library/system.net.sockets.tcplistener.aspx[^]make sure that you select the right version of .net for your client implmentation for the example.
4 Aug 2019 by Member 14179902
I want to divide the integrated input I get from a TCP connection(in bytes) into several different byte arrays.I have a server and client. server that encrypts a message by 3DES and encrypts the key and IV by RSA. Then it concatenates them together like this (plaintext + ciphertext + key + IV)...
4 Aug 2019 by RickZeeland
See: Array.CopyTo Method (System) | Microsoft Docs[^] Or the alternative: Buffer.BlockCopy[^]
1 Aug 2015 by Umut Comlekcioglu
Hi everyone,TcpListener list = new TcpListener(new IPEndPoint(IPAddress.Parse("192.168.1.36"), 11000));list.Start(); list.BeginAcceptTcpClient(AcceptCallback, null);I'm write that code into my Server and I can connect Server with Windows Client. s = new Socket("192.168.1.36",...
1 Aug 2015 by Richard MacCutchan
Lots of samples to be found by https://www.google.com/search?q=android%20sockets[^].
24 Aug 2013 by Sicppy
I am trying to make a custom proxy application in c# and i need to know how to do the following. - Intercept all outgoing data - Send data to proxy server - Complete connections to intended destination - Return data to clientI am completely lost and would not begin to...
30 Jan 2013 by Member 9557085
I am trying to develop an application that runs sql scripts either or on a local or on a remote sql server to update values on the application. The connection status is checked using:TcpClient client = new TcpClient(serverName, 1433);Once we know that we can listen using the port, I will...
30 Jan 2013 by Dave Kreskowiak
You wouldn't normally do this. At install time, you'd ask the person installing the app for the name of the SQL Server and instance, port number, and credentials to use, giving them the option of using Windows Authentication. You'd then construct the connection string from that information and...
29 Apr 2013 by Kasn nimith
Do routers block TCP clients ? , Is skype not using a TCP client socket ? Does skype use a TCP client ? ,IF skype not use tcp client, then how Skype connect to each other ? When TCP Listener is available on internet, Does TCP clients get blocked when try to connect to TCP Socket server...
19 May 2016 by violence666
i have made a code in which i receive the live stream on my client from my Raspberry pion my Pi (server) i have used a netcat command pi@raspberrypi ~ $ raspivid -t 0 -o - | nc -l 5001 on the receiver, i store the received data in a buffer, and then that buffer i pass it to my decoder...
3 Dec 2012 by Deenuji
i wanna send one file through ip address i got error like this No connection could be made because the target machine actively refused it 192.168.1.20:80Below coding i written in this program....this is program error or it's related to firewall proble....but in my system i disable the...
10 Oct 2012 by Brian C Hart
I am working with VS2008 and .NET 3.5. the server and client are both on Win7.I have a server and a client who are using the STX/ETX protocol. The server opens a TcpListener on port xxxx and what the basic thing is that the server waits for connection to come in on that port, and once a...
23 Mar 2021 by Espen Harlinn
A .NET Core client implemented in C# using TcpClient and a multi-threaded server implemented in C++
24 Oct 2017 by Hendrik Vis
I'm trying to connect to a server coded using C++ and an openssl wrapper. I'm using C#. The server has provided me with: 1. A certificate (.crt - header of "-----BEGIN TRUSTED CERTIFICATE-----") 2. A private, encrypted key (.key - header of "-----BEGIN ENCRYPTED PRIVATE KEY-----"). This key is...
2 Dec 2014 by xthehacker2000x2
Hi everyone, thank you for trying to help meI'm making a DVD Farm on the cheap and i'm trying to write the code for myself in VB.Neti have made a software that runs on every computer and a software for the main computer that sends commands to all of them.Now, i always want the machines...
2 Dec 2014 by Sergey Alexandrovich Kryukov
I don't understand why would you use client.Connected at all. The problem looks very simple to me; I face such disconnections everywhere and never had problems with it.The idea is: you should have some main cycle where you exchange data with all clients. Inside that cycle, everything should...
24 Mar 2014 by Brian Honde
I managed to create a TCP Server but I want to know how to send an acknowledgement to the client. I am communicating with an HL7 system using a specified port number.
4 Dec 2022 by Member 14623639
I have searched everywhere but couldn't find as they are all answering to send message to all clients. What I want to achieve is multiple clients request to server to request data from another client and other client sends data to server telling...
12 Nov 2023 by headshot9x
I have a WinForms application C#. In here, I used TcpClient/Socket and NetworkStream. I have created multiple thread to handle sending/receiving from client/server. Assuming I'm forced to use TcpClient/Socket, I won't use other libraries or...
21 Mar 2019 by Richard MacCutchan
Please use Google to find research information. The question is far too broad to be answered in a quick answers forum.
22 Jul 2014 by SrinivasEng
Dear All, I have a Tcp CLient Application, which will connect to a Hardware Server via Ethernet Tcp/Ip for Sending and receiving data.Now I want to check whether Connection between My Application and Server is Active or broken continuously.I tried the following...
2 Jun 2015 by Member 11723960
I need make a chat where i achieve connect a tcp client C# with client html, but there are not a lot of information about what i want to do, if someone already did something like this, i'd appreciate your help. Basically I'm trying make a windows form application to send text to client html on...
11 Jun 2015 by dabuskol
Hi,Below the code that I've got from the net to communicate to unix from .net (c#)unfortunately, the code works can connect but return a garbage result.it also displays that I can connect with the ip/port.The objective is to connect to unix with userid/pass and execute a command...
11 Jun 2015 by _Asif_
This[^] should give you a good start
5 Apr 2021 by Member 14743579
I am trying to connect multiple devices with server using same port number with the help TCP but i am not able to understand the logic to how to connect multiple devices with server using same port and how to communicate with device after the...
5 Apr 2021 by Richard MacCutchan
Whenever a client connection request is accepted by the server, the system returns the new file descriptor for that socket. So you need to keep a list of all socketfds as the server accepts them in order to know which client you are communicating...
5 Apr 2021 by Greg Utas
If you want to look at some C++ code for a thread that handles TCP, on either the server or client side, here[^] is an example. Start in the Enter function on line 332. This has been tested under load on Windows. The comments in its header[^]...
16 Oct 2013 by chester_it21
dear all master,corresponding tag title line above me ,explanation of cases like this :There is a TCP / IP socket server that is already running ...later application TCP / IP would I make must be connected to a TCP / IP Socket Server that is running the ...and his process is ,...
16 Oct 2013 by Sergey Alexandrovich Kryukov
It's not quite clear where you see the problem, but my past answers may give you some ideas:an amateur question in socket programming[^],Multple clients from same port Number[^].Please read and ask your follow-up questions if you have to.—SA
7 Sep 2022 by Gcobani Mkontwana
I a new to WPF but so far managed to create a status bar, but i want to create a grid with columns. I want to create this logic to it; // Requirement that must implement. 0 I need some help, I have status bar but want to implement following...
7 Sep 2022 by Maciej Los
Start here: How to: Create a Grid Element - WPF .NET Framework | Microsoft Docs[^]
23 Apr 2019 by DoingWork
How to detect closed TCP connection when Client disconnected disgracfully i.e sudden power off ? Following method don't work when client disconnects disgracefully. What I have tried: if (socket != null) { bool part1 = socket.Poll(1000,...
23 Apr 2019 by RickZeeland
I used something like this: bool connectedLocal = true; using (var socketTemp = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)) { socketTemp.Connect(ip, port); // Loop until prg...
23 Apr 2019 by User 11060979
TCP keepalive These looks promising, answer 3 in .net - Instantly detect client disconnection from server socket - Stack Overflow[^] and also here: http://tldp.org/HOWTO/TCP-Keepalive-HOWTO/overview.html[^] I hope it helps.
17 Sep 2013 by vr999999999
I want to get data automatically from tcp sockets winsock2. Currently i am using a timer to receive data when its available on socket .Please somebody help me .my current codetcp.h ifndef TCP_H #define TCP_H #pragma once #include #include...
17 Sep 2013 by nv3
You may call recv in a loop. It will block when no data are available and return only when data has been received or a socket error has occurred.If your program has other things to do in parallel while you are waiting for the next data package to arrive, then you should run the receive loop...
23 Aug 2019 by Muhammad Afaq Riaz
I am working with sockets. I have written code for python server which will receive data from a c# client and will display it in the console. The data may be an image or a text. Now problem is that how to differentiate between image and text because text must be displayed in the console and...
23 Aug 2019 by Richard MacCutchan
You need to add some extra data to each message that identifies what is being sent - text or image.
28 Oct 2018 by sirisha.basavaraju
The Windows service is trying to connect to TCP Port and read data. The service worked fine on developer machine but when it is deployed to a laptop for demo purpose the service is trying to connect to the TCP but not getting connected. Please suggest if any permissions are missing. Also, I...
19 Oct 2016 by Member 11543226
I have written a code to receive data from networkstream and if data contains first character "$" then i identify this data as barcodes data, but sometimes when data is large like 7000byte at that time data coming in packets of different sizes but some bytes not detected as they miss "$" symbol...
19 Oct 2016 by johannesnestler
Have a look on MSDN and inspect this sample to see a way how you could do it (it reads till but just replace with your special character(s)https://msdn.microsoft.com/de-de/library/fx6588te(v=vs.110).aspx
16 Oct 2018 by sirisha.basavaraju
Hi all, I have to write a service, where the service has to listen continuosly from the TCP port of the system where it is deployed. I tried few Console Examples but dont know what the mistake they are not working. thanks in advance. What I have tried: I tried using the following code: ...
16 Oct 2018 by Kornfeld Eliyahu Peter
TcpListener.AcceptTcpClient is a blocking method. It will not return until a connection made... In your case it means that no connection on that address and port... As you state that some test software does recognize the device, you probably have the wrong settings (IP/port)...
6 Sep 2017 by Nitin Surya
Hello, i want to send data from the same port on which i have received the data. for eg. i have made tcp listener using UNOLibs. so for receiving and sending is working ok. But the problem is if i receive data on port no 6666 then i need to reply from port no. 6666. i cannot find out the way to...
6 Sep 2017 by Graeme_Grant
There are plenty of articles right here on Code Project that cover this topic: TCP - CodeProject search[^] - Pick one.
17 Feb 2015 by vikaskallidantheyil
hello i am building a simple winform application for data transfer using Socket programming in c#.i have a client and server wherin client can retrive,upload, and delete a file in server using my application. everything is working fine, but i am unable to open retrieved or uploaded file. i...
17 Feb 2015 by Abhinav S
Links -Sending Files using TCP[^]Creating Simple TCP/IP Server And Client to Transfer Data Using C# / VB.net[^]Video - https://www.youtube.com/watch?v=ujYc6qPgn-8[^]
8 Mar 2015 by Peter Van Cauwenberghe
This may not be a pure c# question but maybe someone also has a similar problem.I use Lxi (http://www.lxistandard.org/About/LXI-Protocols.aspx) to communicate with for example Agilent power supplies, scopes etc...There are several ways to do this, but the most easy way is to use SPCI (a...
9 Mar 2015 by Peter Van Cauwenberghe
I had it working now. I posted my question a little to early. :-)But anyway here it the solution : It seemed that it is necessary to send a linefeed after the binary data that needs to be send. So the SPCI command would be in it's complete form :[SPCI COMMAND][Space][BINARY...
12 Mar 2015 by orgilhp
In my code, shown below, server sends 2 responses separately at one time to the client. But my client gets only 1st response and did not get 2nd one. What happened to 2nd response?Client side code (section of receiving data from server):while (true){ NetworkStream networkStream =...
13 Mar 2015 by orgilhp
Thanks _duDE_ for the reply,I have tried your solution. But server still sends only first respose. :(
21 Jun 2015 by Mahmoud_Gamal
i need help to send unsigned character over tcp in unix but it case error in this linevoid Write(char * a,int size){ unsigned char dt []=a;// erorr write(Socket,a,2); // error }
27 Oct 2014 by Jochen Arndt
Just pass the file descriptor, arr and size to the write function. The type of the buffer pointer does not care as far as the count parameter specifies a valid number of bytes contained in the buffer. See also man 2 write[^].The write function just transfers data. It does not care what kind...
27 Oct 2014 by Orjan Westin
Internally, a signed and an unsigned type are the same. The char you send is just 8 bits of data, just like an unsigned char. Therefore,void Write(char * arr,int size){ unsigned char* dt = (unsigned char*)a; // Cast to the type you want write(Socket,dt,size);}will send exactly the...
27 Oct 2014 by Mahmoud_Gamal
i solve it temporary like this void WriteU(unsigned char buff[], int size){ int h ; h = write( m_Client->Socket,buff,size);// printf("\n data write \n %i",h);}why i tired my self if there is another way
21 Jun 2015 by Richard MacCutchan
Your Write function takes a character pointer as input, so trying to use that as an unsigned pointer makes no sense. You should just use the standard socket write function as described in http://man7.org/linux/man-pages/man2/write.2.html[^].
16 Apr 2018 by Member 13759064
So I have created a client and a server howerver whenever I run multiple clients and then close 1 of them the other clients disconnect as soon as they try to message other active clients. This may be due to a mistake inside my code however I still cant manage to find where the problem lies. ...
16 Apr 2018 by Wendelius
I didn't go through all the code but looking at the exception handling in doChat it looks like when an exception occurs you assume that the client has disconnected. However, there are tons of reasons why an exception might occur. So my suggestion is, modify the exception handling so that you...
11 Apr 2014 by laxman ghadage
hi, I have written for connectivity using tcpclient.but after every successful transaction it creates new session for each request.please do help..thanks in advance.my code is as..namespace CBS{ class TCPListner { private static string hostName = ""; ...
6 Oct 2016 by Member 12682888
I am working on vehicle Tracking System. I did TCP listner server. I want to host this on server. how do i achieve it? or other than winform their is any way in .Net ThanksWhat I have tried:I am working on vehicle Tracking System. I did TCP listner server. I want to host this on...
6 Oct 2016 by F-ES Sitecore
Host it on what server? On the internet? If so hire a virtual server with (ideally) a fixed IP. You should implement your code as a Windows Service and install the service on your server.
6 Oct 2016 by Member 12682888
thank for quick reply.I implement code in Windows Service. when i start service port goes open its OK, while after client connect its work, but when client send data to server automatically service stop.i dont know exact reason please help me
19 Apr 2018 by Member 13695363
I would like to communicate with a USB device attached to a client system via Internet, I have to connect to the port the device is connected to on the client side, and then invoke the execution of a function on my side, So in a scence I need to communicate with that USB device without having...
19 Apr 2018 by F-ES Sitecore
Would you want services accessing your USB devices? Of course this isn't possible.
19 Apr 2018 by Patrice T
By principle, a remote server don't have access to a PC if user don't cooperate. Cooperation can be HDD or printer sharing, but you need credentials. Cooperation can be client opening a web app from server, it open access to cam, but only if client allow it. In order to expose the cam to web app...
18 Mar 2015 by orgilhp
I'm writing TCP client server software using C#. I want client be connected with server automatically as soon as server started. To do this task, client may need to know whether the server is started or not. But how, is it possible?My situation: There is one client and one server on the same...
18 Mar 2015 by Dave Kreskowiak
No, this is not how it's done.Think about it. How is the server going to know that there are clients to connect to? How is the server going to find them??It's not.
18 Mar 2015 by E.F. Nijboer
The client has to setup the connection because most clients are behind a router (NAT.) It prevents incoming connections to the client from anyone outside of the NAT. Meaning servers are reachable over the internet and clients are (mostly) not. But polling every x minutes should't be that bad....
18 Mar 2015 by manchanx
I don't think this makes a lot of sense. However, if you really want to do that, you can just keep the client trying to connect in a loop.
31 Jul 2017 by Member 13337752
I've made a client/Server app using TCP sockets, but clients stuck too often and they throw "Connection timed out" while reading for new messages from the Server. On both apps im using this: try{ do{ message=(String) input.readLine(); ...
31 Jul 2017 by Thomas Daniels
Yes, there is a difference. In the first code block, when there's an error in the try block, you exit the do-while loop and go into catch. readLine does not get called anymore, because the code that goes after the catch block gets executed now. In the second code block, when there's an error...
7 Jul 2016 by Member 10710536
I would like to write a programm to communicate with a modbus TCP/IP slave.I found some library's but they are all for .net.I would like to use windows UWP. So i believe i have to have a library for the .NETcore.Can someone help me with thisWhat I have tried:I already tried...
22 Mar 2013 by Amir Jalilifard
Hi there,I am confused to understand that is this application a Peer to Peer application?WCF TCP-based File Server[^]Is TCP a different concept than P2P?So what is different between net.tcp:// and net.p2p:// in addressing ?