getting exception from server in c# socket - c#

I have created a simple server and client program in c#. The server will send a string array to the client and the client will display it and the client will sent an id to server and the server will display it. My sample code is given below. When I run them, I get an exception in the server side. I have marked the line in which I am getting the exception.My sample code is given below:
server:
using System;
using System.Collections.Generic;
using System.Net;
using System.Net.Sockets;
using System.IO;
using System.Text;
using System.Xml.Serialization;
namespace server
{
class Program
{
static void Main(string[] args)
{
TcpListener tcpListener = new TcpListener(IPAddress.Any, 1234);
tcpListener.Start();
while (true)
{
TcpClient tcpClient = tcpListener.AcceptTcpClient();
byte[] data = new byte[1024];
NetworkStream ns = tcpClient.GetStream();
string[] arr1 = new string[] { "one", "two", "three" };
var serializer = new XmlSerializer(typeof(string[]));
serializer.Serialize(tcpClient.GetStream(), arr1);
tcpClient.Close();
int recv = ns.Read(data, 0, data.Length); //getting exception in this line
string id = Encoding.ASCII.GetString(data, 0, recv);
Console.WriteLine(id);
}
}
}
}
client :
using System;
using System.Collections.Generic;
using System.Net;
using System.Net.Sockets;
using System.IO;
using System.Text;
using System.Xml.Serialization;
namespace Client
{
class Program
{
static void Main(string[] args)
{
try
{
byte[] data = new byte[1024];
string stringData;
TcpClient tcpClient = new TcpClient("127.0.0.1", 1234);
NetworkStream ns = tcpClient.GetStream();
var serializer = new XmlSerializer(typeof(string[]));
var stringArr = (string[])serializer.Deserialize(tcpClient.GetStream());
foreach (string s in stringArr)
{
Console.WriteLine(s);
}
string input = Console.ReadLine();
ns.Write(Encoding.ASCII.GetBytes(input), 0, input.Length);
ns.Flush();
}
catch (Exception e)
{
Console.Write(e.Message);
}
Console.Read();
}
}
}
The exception I am getting is:
An unhandled exception of type 'System.ObjectDisposedException' occurred in System.dll
Additional information: Cannot access a disposed object.
Is there anything wrong in the code? What will I need to do to avoid this exception?

It seems to me that in your server code you are closing the TCP client before you continue with reading the data. This is why you are getting the exception.
Also, you are trying to read 1024 bytes, but the client does not send 1024 (unless by an unlikely chance that the string that the client sends which is an input from the user is encoded into a 1024 byte array) so the server will simply block and do nothing because it is waiting for the client to send 1024 bytes.
One good way to manage reading and writing data from/to a stream is through the BinaryReader and BinaryWriter classes.
Consider the following code to solve your issue (it contains some improvements to your code):
Server:
class Program
{
static void Main(string[] args)
{
TcpListener tcpListener = new TcpListener(IPAddress.Any, 1234);
tcpListener.Start();
while (true)
{
using (TcpClient tcpClient = tcpListener.AcceptTcpClient())
{
using (var network_stream = tcpClient.GetStream())
{
using (BinaryReader reader = new BinaryReader(network_stream))
{
using (BinaryWriter writer = new BinaryWriter(network_stream))
{
string[] arr1 = new string[] { "one", "two", "three" };
writer.Write(arr1.Length);
foreach (var item in arr1)
{
writer.Write(item);
}
var id = reader.ReadString();
Console.WriteLine("Id: " + id);
}
}
}
}
}
}
}
Client:
class Program
{
static void Main(string[] args)
{
try
{
using (TcpClient tcpClient = new TcpClient("127.0.0.1", 1234))
{
using (NetworkStream network_stream = tcpClient.GetStream())
{
using (BinaryReader reader = new BinaryReader(network_stream))
{
using (BinaryWriter writer = new BinaryWriter(network_stream))
{
int number_of_strings = reader.ReadInt32();
string[] lines = new string[number_of_strings];
for(int i = 0 ; i < number_of_strings ; i++)
{
lines[i] = reader.ReadString(); //Store the strings if you want to
Console.WriteLine(lines[i]);
}
Console.WriteLine("Please input id:");
string id = Console.ReadLine();
writer.Write(id);
}
}
}
}
}
catch (Exception e)
{
Console.Write(e.Message);
}
Console.Read();
}
}

You are using the NetworkStream after you have Closed the TcpClient (which disposed it). See updated while below:
while (true)
{
var tcpClient = tcpListener.AcceptTcpClient();
var data = new byte[1024];
var arr1 = new string[] { "one", "two", "three" };
var serializer = new XmlSerializer(typeof(string[]));
serializer.Serialize(tcpClient.GetStream(), arr1);
var ns = tcpClient.GetStream();
var recv = ns.Read(data, 0, data.Length); //getting exception in this line
var id = Encoding.ASCII.GetString(data, 0, recv);
Console.WriteLine(id);
ns.Close();
tcpClient.Close();
}

tcpClient Implementing Idisposible interface it is better to call dispose method in tcpclient
tcpClient.Dispose();
else
tcpClient.GetStream().Close();
tcpClient.Close();
Closing the client does not close the stream.
var serializer = new XmlSerializer(typeof(string[]));
serializer.Serialize(tcpClient.GetStream(), arr1);
tcpClient.GetStream().Close()
tcpClient.Close();

Related

NetworkStream cuts off first 4 bytes when reading

I ran into a strange problem. When I'm trying to send the file via a TCP socket, the first 4 bytes of sended information cuts off.
That is sending and receives pieces of code.
Client side
for (var i = 0; i < fileContentByte.Length; i += buffer.Length)
{
var size = (i + buffer.Length > fileContentByte.Length) ? fileContentByte.Length - i : buffer.Length;
clientSocket.Write(fileContentByte, i, size);
}
Server side
using(var file = File.Create("C:\\test\\"+fileName.Substring(0, fileName.IndexOf('\0'))))
while(bytesReceived < numberOfBytes && (count = clientStream.Read(buffer, 0, buffer.Length)) > 0)
{
file.Write(buffer, 0, count);
bytesReceived += count;
}
Here is link on full code - http://pastebin.com/VwTgTxgb
You're doing something very strange here.
First of all, retrieval of file name can be greatly simplified down to Path.GetFileName() call.
Second, are you sure ASCII will suffice?
Third, reading the entire file into memory is OK-ish for a proof-of-concept project, but be ready to switch to streaming operations.
Fourth, your protocol is somewhat wonky. When sending variable-size payload, it is required to first tell the receiving party exactly how much bytes are you going to send. This is exactly what you don't do when sending file name.
Here's a snippet to get you started:
using System;
using System.Diagnostics;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Text;
namespace FolderSync
{
class Program
{
static void Main()
{
var server = new Server();
server.Start();
new Client().TransmitFile(
new IPEndPoint(IPAddress.Loopback, 35434),
#"f:\downloads\ubuntu-14.04.3-desktop-amd64.iso");
Console.ReadLine();
server.Stop();
}
}
class Server
{
private readonly TcpListener tcpListener;
public Server()
{
tcpListener = new TcpListener(IPAddress.Loopback, 35434);
}
public void Start()
{
tcpListener.Start();
tcpListener.BeginAcceptTcpClient(AcceptTcpClientCallback, null);
}
public void Stop()
{
tcpListener.Stop();
}
private void AcceptTcpClientCallback(IAsyncResult asyncResult)
{
//
// Big fat warning: http://stackoverflow.com/a/1230266/60188
tcpListener.BeginAcceptTcpClient(AcceptTcpClientCallback, null);
using(var tcpClient = tcpListener.EndAcceptTcpClient(asyncResult))
using(var networkStream = tcpClient.GetStream())
using(var binaryReader = new BinaryReader(networkStream, Encoding.UTF8))
{
var fileName = binaryReader.ReadString();
var length = binaryReader.ReadInt64();
var mib = length / 1024.0 / 1024.0;
Console.WriteLine("Receiving '{0}' ({1:N1} MiB)", fileName, mib);
var stopwatch = Stopwatch.StartNew();
var fullFilePath = Path.Combine(Path.GetTempPath(), fileName);
using(var fileStream = File.Create(fullFilePath))
networkStream.CopyTo(fileStream);
var elapsed = stopwatch.Elapsed;
Console.WriteLine("Received in {0} ({1:N1} MiB/sec)",
elapsed, mib / elapsed.TotalSeconds);
}
}
}
class Client
{
public void TransmitFile(IPEndPoint endPoint, string fileFullPath)
{
if(!File.Exists(fileFullPath)) return;
using(var tcpClient = new TcpClient())
{
tcpClient.Connect(endPoint);
using(var networkStream = tcpClient.GetStream())
using(var binaryWriter = new BinaryWriter(networkStream, Encoding.UTF8))
{
var fileName = Path.GetFileName(fileFullPath);
Debug.Assert(fileName != null, "fileName != null");
//
// BinaryWriter.Write(string) does length-prefixing automatically
binaryWriter.Write(fileName);
using(var fileStream = File.OpenRead(fileFullPath))
{
binaryWriter.Write(fileStream.Length);
fileStream.CopyTo(networkStream);
}
}
}
}
}
}

c# TCP NetworkStream is not receiving data

I'm trying to send files after sending their's information via TCP connection. At the end of receiver host, the data packets are received. I used Wireshark to confirm it. However the data couldn't be received in NetworkStream.
public class FileTransporter
{
public void ReceiveFiles(IPAddress IP, int port)
{
TcpListener tcpListener = new TcpListener(IP, port);
tcpListener.Start();
using (TcpClient tcpClient = tcpListener.AcceptTcpClient())
{
if (tcpClient.Connected)
{
using (NetworkStream networkStream = tcpClient.GetStream())
{
int pointer = 0;
byte[] fileNameLengthBytes = new byte[sizeof(int)];
networkStream.Read(fileNameLengthBytes, pointer, fileNameLengthBytes.Length);
int fileNameLength = BitConverter.ToInt32(fileNameLengthBytes, pointer);
// code to read fileName and it's size
networkStream.Close();
}
}
tcpClient.Close();
}
tcpListener.Stop();
}
public void SendFiles(IPAddress IP, int port, string[] paths)
{
for(int i=0; i<paths.Length; i++)
{
FilePackage filePackage = new FilePackage(paths[i]);
byte[] infoBytes = filePackage.EncodeInfoToByte();
using (TcpClient tcpClient = new TcpClient())
{
tcpClient.Connect(IP, port);
using (NetworkStream networkStream = tcpClient.GetStream())
{
networkStream.Write(infoBytes, 0, infoBytes.Length);
networkStream.Close();
}
tcpClient.Close();
}
}
}
}
public class FilePackage
{
public FilePackage(string fileName)
{
this.Info = new FileInfo(fileName);
}
public byte[] EncodeInfoToByte()
{
List<byte> infoByte = new List<byte>();
infoByte.AddRange(BitConverter.GetBytes(this.Info.Name.Length));
infoByte.AddRange(Encoding.UTF8.GetBytes(this.Info.Name));
infoByte.AddRange(BitConverter.GetBytes(this.Info.Length));
return infoByte.ToArray();
}
I am going to Assume that ReadFiles is invoked somehow / somewhere else.
I have a very similar implementation, however my "Read" of the stream is much smaller:
// Read the first batch of the TcpServer response bytes.
var bytes = new byte[512];
// Loop to receive all the data sent by the Server.
var sb = new StringBuilder();
do
{
var i = stream.Read(bytes, 0, bytes.Length);
sb.AppendFormat("{0}", Encoding.ASCII.GetString(bytes, 0, i));
} while (stream.DataAvailable);
Perhaps using "stream.DataAvailable" will allow you to test for data existence and that way you can make sure that you only process when data is available.
Also I don't see where "pointer" is being initialized in your code.
If it is not set to 0 each time, you will not be processing from the beginning of the data packet.
Your problem is probably being caused by the nagle algorithm, prevent small amounts of data being sent to reduce congestion. You could try disabling it by setting the following properties on your tcpClient
tcpClient.NoDelay = true;
tcpClient.Client.NoDelay = true

Writing/reading string through NetworkStream (sockets) for a chat

Sorry if this is hard to understand, trying out C# for the first time.
I am trying to make a simple public 'chat' between clients that are connected to the server. I've tried passing integers to the server and printing them out and everything was fine, however,when I switched to strings, it seems that it can only pass 1 character (because of ns.Write(converted, 0, 1);). If I increase the ns.Write to ns.Write(converted,0,10) everything crashes (both the client and the server) when I enter a message that is less than 10 characters.
Server code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Net.Sockets;
namespace MultiServeris
{
class Multiserveris
{
static void Main(string[] args)
{
TcpListener ServerSocket = new TcpListener(1000);
ServerSocket.Start();
Console.WriteLine("Server started");
while (true)
{
TcpClient clientSocket = ServerSocket.AcceptTcpClient();
handleClient client = new handleClient();
client.startClient(clientSocket);
}
}
}
public class handleClient
{
TcpClient clientSocket;
public void startClient(TcpClient inClientSocket)
{
this.clientSocket = inClientSocket;
Thread ctThread = new Thread(Chat);
ctThread.Start();
}
private void Chat()
{
byte[] buffer = new byte[10];
while (true)
{
NetworkStream ns = clientSocket.GetStream();
ns.Read(buffer,0,1);
string line = Encoding.UTF8.GetString(buffer);
Console.WriteLine(line);
}
}
}
}
Client code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net.Sockets;
namespace Klientas
{
class Klientas
{
static void Main(string[] args)
{
while (true)
{
TcpClient clientSocket = new TcpClient("localhost", 1000);
NetworkStream ns = clientSocket.GetStream();
byte[] buffer = new byte[10];
string str = Console.ReadLine();
byte[] converted = System.Text.Encoding.UTF8.GetBytes(str);
ns.Write(converted, 0, 1);
}
}
}
}
You're best using the BinaryReader/BinaryWriter classes to correctly format and read out data. This removes the need to process it yourself. For example in the client do:
BinaryWriter writer = new BinaryWriter(clientSocket.GetStream());
writer.Write(str);
And in the server:
BinaryReader reader = new BinaryReader(clientSocket.GetStream());
Console.WriteLine(reader.ReadString());
When using BinaryReader or BinaryWriter on the same stream, and you have .NET framework version 4.5 or above, be sure to leave the underlying stream open by using the overload:
using (var w = new BinaryWriter(stream, Encoding.UTF8, true)) {}

How to End NetworkStream.Read() safely ? (in C# or VB.net)

I wrote a class that tries to read byte data sent by a server, and when my app ends, I also want the loop to end, but it appears NetworkStream.Read() just waits if no data is ever available.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net.Sockets;
using System.Threading;
using System.Net;
using System.Threading.Tasks;
namespace Stream
{
class Program
{
private static TcpClient client = new TcpClient("127.0.0.1", 80);
private static NetworkStream stream = client.GetStream();
static void Main(string[] args)
{
var p = new Program();
p.Run();
}
void Run()
{
ThreadPool.QueueUserWorkItem(x =>
{
while (true)
{
stream.Read(new byte[64], 0, 64);
}
});
client.Close();
// insert Console.ReadLine(); if you want to see an exception occur.
}
}
}
With this code, we'd get
System.IO.IOException saying "Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host",
ObjectDisposedException saying "Cannot access a disposed object", or
System.IO.IOException saying "A blocking operation was interrupted by a call to WSACancelBlockingCall".
So how could I safely end this method?
From what I can see when running your program, your 1st exception "Unable to read data from the transport connection..." is not thrown by the Stream.Read but by the TcpClient's constructor and is most probably due to the fact that there is no server accepting connections on 127.0.0.1:80.
Now if you want to end nicely on the Stream.Read, I would do it asynchronously. In this way you can catch any exceptions thrown during the Read and clean you program accordingly. Here is a modified version of your program:
using System;
using System.Net.Sockets;
namespace Stream
{
class Program
{
private static TcpClient client;
private static NetworkStream stream;
static void Main(string[] args)
{
var p = new Program();
p.Run();
}
void Run()
{
try
{
client = new TcpClient("127.0.0.1", 80);
stream = client.GetStream();
byte[] buffer = new byte[64];
stream.BeginRead(buffer, 0, buffer.Length, new AsyncCallback(OnRead), buffer);
client.Close();
Console.ReadKey();
}
catch (Exception)
{
//...
}
}
void OnRead(IAsyncResult result)
{
try
{
stream.EndRead(result);
byte[] buffer = result.AsyncState as byte[];
if (buffer != null)
{
//...
}
// continue to read the next 64 bytes
buffer = new byte[64];
stream.BeginRead(buffer, 0, buffer.Length, new AsyncCallback(OnRead), buffer);
}
catch (Exception)
{
// From here you can get exceptions thrown during the asynchronous read
}
}
}
}
To avoid blocking, only call Read() when DataAvailable is true.
The ThreadPool isn't suited for long-running tasks, so refactor your while loop
You close the connection before you read from it (as the work item is executed async).
This might help
void Run() {
ThreadPool.QueueUserWorkItem(ReadLoop);
}
void ReadLoop(object x) {
if (stream.DataAvailable)
stream.Read(new byte[64], 0, 64);
else
Thread.Sleep(TimeSpan.FromMilliseconds(200));
if (Finished)
client.Close();
else if (!Disposed && !Finished)
ThreadPool.QueueUserWorkItem(ReadLoop);
}
You'll need to manage the Finished & Disposed yourself in your real class.
If the simple console client application is implemented, then why use another thread to connect and receive the data from server?
static void Main(string[] args)
{
var client = new TcpClient("...", ...);
var buffer = new byte[1024];
using (var networkStream = client.GetStream())
{
int bytesRead;
while ((bytesRead = networkStream.Read(buffer, 0, buffer.Length)) > 0)
{
var hexString = BitConverter.ToString(buffer, 0, bytesRead);
Console.WriteLine("Bytes received: {0}", hexString);
}
}
}

How can i get more than one jpg. or txt file from any folder?

i have two Application to listen network Stream : Server.cs on the other hand; send file Client.cs. But i want to send more files on a stream from any folder. For example. i have C:/folder whish has got 3 jpg files. My client must run. Also My server.cs get files on stream:
Client.cs:
private void btn_send2_Click(object sender, EventArgs e)
{
string[] paths= null;
paths= System.IO.Directory.GetFiles(#"C:\folder" + #"\", "*.jpg", System.IO.SearchOption.AllDirectories);
byte[] Dizi;
TcpClient Gonder = new TcpClient("127.0.0.1", 51124);
FileStream Dosya;
FileInfo Dos;
NetworkStream Akis;
foreach (string path in paths)
{
Dosya = new FileStream(path , FileMode.OpenOrCreate);
Dos = new FileInfo(path );
Dizi = new byte[(int)Dos.Length];
Dosya.Read(Dizi, 0, (int)Dos.Length);
Akis = Gonder.GetStream();
Akis.Write(Dizi, 0, (int)Dosya.Length);
Gonder.Close();
Akis.Flush();
Dosya.Close();
}
}
Also i have Server.cs
void Dinle()
{
TcpListener server = null;
try
{
Int32 port = 51124;
IPAddress localAddr = IPAddress.Parse("127.0.0.1");
server = new TcpListener(localAddr, port);
server.Start();
Byte[] bytes = new Byte[1024 * 250000];
// string ReceivedPath = "C:/recieved";
while (true)
{
MessageBox.Show("Waiting for a connection... ");
TcpClient client = server.AcceptTcpClient();
MessageBox.Show("Connected!");
NetworkStream stream = client.GetStream();
if (stream.CanRead)
{
saveFileDialog1.ShowDialog();
// burası degişecek
string pathfolder = saveFileDialog1.FileName;
StreamWriter yaz = new StreamWriter(pathfolder);
string satir;
StreamReader oku = new StreamReader(stream);
while ((satir = oku.ReadLine()) != null)
{
satir = satir + (char)13 + (char)10;
yaz.WriteLine(satir);
}
oku.Close();
yaz.Close();
client.Close();
}
}
}
catch (SocketException e)
{
Console.WriteLine("SocketException: {0}", e);
}
finally
{
// Stop listening for new clients.
server.Stop();
}
Console.WriteLine("\nHit enter to continue...");
Console.Read();
}
Please look Client.cs: icollected all files from "c:\folder"
paths= System.IO.Directory.GetFiles(#"C:\folder" + #"\", "*.jpg", System.IO.SearchOption.AllDirectories);
My Server.cs how to get all files from stream?
It's not a typical way of doing things.
Usually you would write a single file in a single stream and repeat the process for multiple files. You risk data corruption this way as you'll have to place some kind of marker in the stream to know where to split it.
The easiest way is to use multiple sockets, one for commands and one (or more) for sending files.
The below code have NOT been tested, just wrote it up to show what I mean. It's multithreaded and can receive multiple files from the same client, just call sendfiles multiple times in the client.
You might want to add error/exception handling if you decide to finish the code.
Server.cs
using System;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Text;
namespace Test2
{
public class Server
{
private readonly TcpListener _listener = new TcpListener(1234);
public void Start()
{
_listener.BeginAcceptTcpClient(OnClient, null);
}
private void OnClient(IAsyncResult ar)
{
// End async accept and start wait for a new connection again
TcpClient client = _listener.EndAcceptTcpClient(ar);
_listener.BeginAcceptTcpClient(OnClient, null);
// Let's start receiving files from the accepted client.
var context = new Context {Client = client, Buffer = new byte[8196]};
client.GetStream().BeginRead(context.Buffer, 0, context.Buffer.Length, OnReceive, context);
}
/// <summary>
/// Got some stuff from a client
/// </summary>
/// <param name="ar"></param>
private void OnReceive(IAsyncResult ar)
{
// got a file command
var context = (Context) ar.AsyncState;
int bytesRead = context.Client.GetStream().EndRead(ar);
string cmd = Encoding.UTF8.GetString(context.Buffer, 0, bytesRead);
string[] parts = cmd.Split(';');
string command = parts[0];
// want to send another file
if (command == "sendfile")
{
// context info for receiving files
var client = new FileClient();
client.FileName = parts[1];
client.Size = long.Parse(parts[2]);
client.FileStream = new FileStream("C:\\" + client.FileName, FileMode.CreateNew, FileAccess.Write);
// startup listener where we are going to receive the file.
var listener = new TcpListener(IPAddress.Any, 0); // get a kernelassigned number
client.Listener = listener;
listener.Start();
listener.BeginAcceptTcpClient(OnFileSocket, client);
// send reply
var ep = (IPEndPoint) listener.LocalEndpoint;
byte[] reply = Encoding.UTF8.GetBytes(ep.Port.ToString());
context.Client.GetStream().Write(reply, 0, reply.Length);
}
}
// Receiving the actual files.
private void OnFileSocket(IAsyncResult ar)
{
var client = (FileClient) ar.AsyncState;
client.Socket = client.Listener.EndAcceptTcpClient(ar);
var buffer = new byte[8192];
client.Buffer = buffer;
client.Socket.GetStream().BeginRead(buffer, 0, buffer.Length, OnReceiveFile, client);
}
private void OnReceiveFile(IAsyncResult ar)
{
var client = (FileClient) ar.AsyncState;
int bytesRead = client.Socket.GetStream().EndRead(ar);
client.Received += bytesRead;
client.FileStream.Write(client.Buffer, 0, bytesRead);
// recieved complete file, disconnect and exit.
if (client.Received == client.Size)
{
client.FileStream.Close();
client.Socket.Close();
return;
}
client.Socket.GetStream().BeginRead(client.Buffer, 0, client.Buffer.Length, OnReceiveFile, client);
}
#region Nested type: Context
private class Context
{
public byte[] Buffer;
public TcpClient Client;
}
#endregion
#region Nested type: FileClient
private class FileClient
{
public byte[] Buffer;
public string FileName;
public FileStream FileStream;
public TcpListener Listener;
public long Received;
public long Size;
public TcpClient Socket;
}
#endregion
}
}
Client.cs
using System;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Text;
namespace Test2
{
internal class Client
{
private readonly IPAddress _server;
private readonly TcpClient _tcpClient = new TcpClient();
public Client(IPAddress server)
{
_server = server;
_tcpClient = new TcpClient();
}
public void Connect()
{
_tcpClient.Connect(new IPEndPoint(_server, 1234));
}
// asks server on which port the file should be sent.
private int RequestPort(string fileName, long length)
{
// lock tpcClient for each request, so we dont mix up the responses.
lock (_tcpClient)
{
// send request
byte[] bytes = Encoding.UTF8.GetBytes("sendfile;" + fileName + ";" + length);
_tcpClient.GetStream().Write(bytes, 0, bytes.Length);
// get reply
var buffer = new byte[1024];
int bytesRead = _tcpClient.GetStream().Read(buffer, 0, buffer.Length);
string reply = Encoding.UTF8.GetString(buffer, 0, bytesRead);
// error message or port?
int port;
if (!int.TryParse(reply, out port))
throw new InvalidOperationException("Server sent an error:" + reply);
return port;
}
}
public void SendFiles(string[] fileNames)
{
// Use a buffer to not preserve memory (instead of reading whole file into memory)
var buffer = new byte[8192];
foreach (string fileName in fileNames)
{
using (var fileStream = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
{
// Send on commandchannel that we want to send a file.
int filePort = RequestPort(Path.GetFileName(fileName), fileStream.Length);
var client = new TcpClient(new IPEndPoint(_server, filePort));
NetworkStream stream = client.GetStream();
// repeat until there are no more bytes to read.
int bytesRead = fileStream.Read(buffer, 0, buffer.Length);
while (bytesRead > 0)
{
stream.Write(buffer, 0, bytesRead);
bytesRead = fileStream.Read(buffer, 0, buffer.Length);
}
stream.Close();
client.Close();
}
}
}
}
}

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