How to read and send data to client from server? - c#

I'm trying to make a server client using a local console server on my pc and a client on windows phone 8.1. The problem that I have is that I don't know how to read the incoming data from the client. I've searched the internet and read serveral microsoft tutorials but they do not explain how to read the incoming data in the server. Here's what I have.
Client on windows phone 8.1:
private async void tryConnect()
{
if (connected)
{
StatusLabel.Text = "Already connected";
return;
}
try
{
// serverHostnameString = "127.0.0.1"
// serverPort = "1330"
StatusLabel.Text = "Trying to connect ...";
serverHost = new HostName(serverHostnameString);
// Try to connect to the
await clientSocket.ConnectAsync(serverHost, serverPort);
connected = true;
StatusLabel.Text = "Connection established" + Environment.NewLine;
}
catch (Exception exception)
{
// If this is an unknown status,
// it means that the error is fatal and retry will likely fail.
if (SocketError.GetStatus(exception.HResult) == SocketErrorStatus.Unknown)
{
throw;
}
StatusLabel.Text = "Connect failed with error: " + exception.Message;
// Could retry the connection, but for this simple example
// just close the socket.
closing = true;
// the Close method is mapped to the C# Dispose
clientSocket.Dispose();
clientSocket = null;
}
}
private async void sendData(string data)
{
if (!connected)
{
StatusLabel.Text = "Must be connected to send!";
return;
}
UInt32 len = 0; // Gets the UTF-8 string length.
try
{
StatusLabel.Text = "Trying to send data ...";
// add a newline to the text to send
string sendData = "jo";
DataWriter writer = new DataWriter(clientSocket.OutputStream);
len = writer.MeasureString(sendData); // Gets the UTF-8 string length.
// Call StoreAsync method to store the data to a backing stream
await writer.StoreAsync();
StatusLabel.Text = "Data was sent" + Environment.NewLine;
// detach the stream and close it
writer.DetachStream();
writer.Dispose();
}
catch (Exception exception)
{
// If this is an unknown status,
// it means that the error is fatal and retry will likely fail.
if (SocketError.GetStatus(exception.HResult) == SocketErrorStatus.Unknown)
{
throw;
}
StatusLabel.Text = "Send data or receive failed with error: " + exception.Message;
// Could retry the connection, but for this simple example
// just close the socket.
closing = true;
clientSocket.Dispose();
clientSocket = null;
connected = false;
}
}
(from http://msdn.microsoft.com/en-us/library/windows/apps/xaml/jj150599.aspx)
And the server:
public class Server
{
private TcpClient incomingClient;
public Server()
{
TcpListener listener = new TcpListener(IPAddress.Parse("127.0.0.1"), 1330);
listener.Start();
Console.WriteLine("Waiting for connection...");
while (true)
{
//AcceptTcpClient waits for a connection from the client
incomingClient = listener.AcceptTcpClient();
//start a new thread to handle this connection so we can go back to waiting for another client
Thread thread = new Thread(HandleClientThread);
thread.IsBackground = true;
thread.Start(incomingClient);
}
}
private void HandleClientThread(object obj)
{
TcpClient client = obj as TcpClient;
Console.WriteLine("Connection found!");
while (true)
{
//how to read and send data back?
}
}
}
It comes to the point where the server prints 'Connection found!', but I don't know how to go further.
Any help is appreciated!
EDIT:
Now my handleclientthread method looks like this:
private void HandleClientThread(object obj)
{
TcpClient client = obj as TcpClient;
netStream = client.GetStream();
byte[] rcvBuffer = new byte[500]; // Receive buffer
int bytesRcvd; // Received byte count
int totalBytesEchoed = 0;
Console.WriteLine("Connection found!");
while (true)
{
while ((bytesRcvd = netStream.Read(rcvBuffer, 0, rcvBuffer.Length)) > 0)
{
netStream.Write(rcvBuffer, 0, bytesRcvd);
totalBytesEchoed += bytesRcvd;
}
Console.WriteLine(totalBytesEchoed);
}
}
But it still doesn't write the bytes to the console

So... after a lot of searching the internet I have found a solution...
Server: to read from the server and send data back to the phone:
// method in a new thread, for each connection
private void HandleClientThread(object obj)
{
TcpClient client = obj as TcpClient;
netStream = client.GetStream();
Console.WriteLine("Connection found!");
while (true)
{
// read data
byte[] buffer = new byte[1024];
int totalRead = 0;
do
{
int read = client.GetStream().Read(buffer, totalRead, buffer.Length - totalRead);
totalRead += read;
} while (client.GetStream().DataAvailable);
string received = Encoding.ASCII.GetString(buffer, 0, totalRead);
Console.WriteLine("\nResponse from client: {0}", received);
// do some actions
byte[] bytes = Encoding.ASCII.GetBytes(received);
// send data back
client.GetStream().WriteAsync(bytes, 0, bytes.Length);
}
}
Phone(client): to send messages from the phone and read the messages from server:
private async void sendData(string dataToSend)
// import for AsBuffer(): using System.Runtime.InteropServices.WindowsRuntime;
{
if (!connected)
{
StatusLabel.Text = "Status: Must be connected to send!";
return;
}
try
{
byte[] data = GetBytes(dataToSend);
IBuffer buffer = data.AsBuffer();
StatusLabel.Text = "Status: Trying to send data ...";
await clientSocket.OutputStream.WriteAsync(buffer);
StatusLabel.Text = "Status: Data was sent" + Environment.NewLine;
}
catch (Exception exception)
{
if (SocketError.GetStatus(exception.HResult) == SocketErrorStatus.Unknown)
{
throw;
}
StatusLabel.Text = "Status: Send data or receive failed with error: " + exception.Message;
closing = true;
clientSocket.Dispose();
clientSocket = null;
connected = false;
}
readData();
}
private async void readData()
{
StatusLabel.Text = "Trying to receive data ...";
try
{
IBuffer buffer = new byte[1024].AsBuffer();
await clientSocket.InputStream.ReadAsync(buffer, buffer.Capacity, InputStreamOptions.Partial);
byte[] result = buffer.ToArray();
StatusLabel.Text = GetString(result);
}
catch (Exception exception)
{
if (SocketError.GetStatus(exception.HResult) == SocketErrorStatus.Unknown)
{
throw;
}
StatusLabel.Text = "Receive failed with error: " + exception.Message;
closing = true;
clientSocket.Dispose();
clientSocket = null;
connected = false;
}
}
The 'await clientSocket.InputStream.ReadAsync(buffer, buffer.Capacity, InputStreamOptions.Partial)' command in the readData method was very unclear for me. I didn't know you had to make a new buffer, and the ReadAsync-method fills it(as i inderstand it). Found it here: StreamSocket.InputStreamOptions.ReadAsync hangs when using Wait()

Related

TCPListener with multiple Clients

I use layered architecture. I create a server. I want the server to listen when the data arrives.
This is my server code in the DataAccess layer.
public class ServerDal : IServerDal
{
private TcpListener server;
private TcpClient client = new TcpClient();
public bool ServerStart(NetStatus netStatus)
{
bool status = false;
try
{
server = new TcpListener(IPAddress.Parse(netStatus.IPAddress), netStatus.Port);
server.Start();
status = true;
}
catch (SocketException ex)
{
Console.WriteLine("Starting Server Error..." + ex);
status = false;
}
return status;
}
public string ReceiveAndSend(NetStatus netStatus)
{
Byte[] bytes = new Byte[1024];
String data = null;
Mutex mutex = new Mutex(false, "TcpIpReceive");
mutex.WaitOne();
if (!client.Connected)
client = server.AcceptTcpClient();
try
{
NetworkStream stream = client.GetStream();
int i;
if ((i = stream.Read(bytes, 0, bytes.Length)) != 0)
{
data = System.Text.Encoding.ASCII.GetString(bytes, 0, i);
Console.WriteLine("Received: " + data);
}
}
catch (Exception ex)
{
Console.WriteLine("Connection Error..." + ex);
client.Close();
}
finally
{
mutex.ReleaseMutex();
}
return data;
}
}
I can listen to the client that first connects to the server. When the first connecting client disconnects, I can listen to the second connecting client.
I want to listen when both clients send data. How can I do that ? Thanks for your help.
I fixed the problem.
static List<TcpClient> tcpClients = new List<TcpClient>();
public void ReceiveMessage(NetStatus netStatus)
{
try {
TcpClient tcpClient = server.AcceptTcpClient();
tcpClients.Add(tcpClient);
Thread thread = new Thread(unused => ClientListener(tcpClient, netStatus));
thread.Start();
}
catch(Exception ex) {
Console.WriteLine("[ERROR...] Server Receive Error = {0} ", ex.Message);
}
}
public void ClientListener(object obj, NetStatus netStatus)
{
try
{
TcpClient tcpClient = (TcpClient)obj;
StreamReader reader = new StreamReader(tcpClient.GetStream());
while(true)
{
string message = null;
message = reader.ReadLine();
if(message!=null)
{
netStatus.IncommingMessage = message;
Console.WriteLine("[INFO....] Received Data = {0}", message);
}
}
}
catch(Exception ex)
{
Console.WriteLine("[ERROR....] ClientListener Error = {0}", ex.Message);
}
}

Unable to read data from tcp server

I have created a simple C# client application. Once it connects to the server it should read the messages sent from the server. It also has the ability to send messages to server too. However I am unable to figure out to correct way to read the data.
I am spawning a thread once it connects to the server. The thread runs in infinite loop and have two interfaces each for reading and writing. Connect() method is called from a ButtonClick event.
My code snippet is as below:
namespace WpfApp1
{
public class TCPClientClass
{
private StreamWriter SwSender;
NetworkStream Sender;
NetworkStream Receiver;
//private StreamReader SrReciever;
private Thread thrMessaging;
TcpClient tcp;
bool connected = false;
public bool Connected { get { return connected; } set { connected = value; } }
//public bool Connect(IPAddress IP, int nPortNo)
public async Task Connect(IPAddress IP, int nPortNo)
{
tcp = new TcpClient();
try
{
//tcp.Connect(strIPAddress.Parse("192.168.137.1"), 2000);
// tcp.Connect(IP , nPortNo);
await tcp.ConnectAsync(IP, nPortNo);
thrMessaging = new Thread(new ThreadStart(ThreadFunction));
thrMessaging.Start();
Connected = true;
}
catch
{
MessageBox.Show("Unable to connect to server");
//return false;
}
//return true;
}
public void Disconnect()
{
Sender?.Close();
Receiver?.Close();
tcp?.Close();
//tcp?.Client.Disconnect(false);
thrMessaging.Abort();
Connected = false;
}
private void ThreadFunction()
{
while (thrMessaging.IsAlive)
DoTasks();
}
private void DoTasks()
{
if (Connected)
{
var a = ReadMessages();
SendMessages();
}
}
private /*void*/async Task ReadMessages()
{
byte[] data = new byte[4096];
//Int32 bytesRead = 0;
//Task<int> bytesReadTask;
String responseData = String.Empty;
Receiver = tcp.GetStream();
try
{
//bytesReadTask = Receiver.ReadAsync(data, 0, data.Length);
//responseData = System.Text.Encoding.ASCII.GetString(data, 0, bytesReadTask.Result);
var response = await Receiver.ReadAsync(data, 0, data.Length);
MessageBox.Show("Server response was " + response);
Thread.Sleep(1000);
}
catch (Exception e)
{
MessageBox.Show(e.Message);
}
}
private void SendMessages()
{
try
{
string strSendData = "Hello from GUI";
Byte[] data = System.Text.Encoding.ASCII.GetBytes(strSendData);
Sender = tcp.GetStream();
Sender.Write(data, 0, data.Length);
Sender.Flush();
Thread.Sleep(1000);
}
catch (Exception e)
{
MessageBox.Show(e.Message);
}
}
}
}
you should change
var response = await Receiver.ReadAsync(data, 0, data.Length);
MessageBox.Show("Server response was " + response);
to
var response = await Receiver.ReadAsync(data, 0, data.Length);
string result = System.Text.Encoding.Default.GetString(data);
MessageBox.Show("Server response was " + result);
if you´re still having problems..my server Code:
public class tcpServer
{
public void method()
{
TcpListener server = new TcpListener(IPAddress.Any, 9999);
server.Start();
TcpClient client = server.AcceptTcpClient();
NetworkStream ns = client.GetStream();
byte[] hello = new byte[100];
hello = Encoding.Default.GetBytes("hello world");
while (client.Connected)
{
ns.Write(hello, 0, hello.Length);
}
}
}

UWP app cannot receive, only send, using sockets

I'm currently developing an UWP app which should have capability to be as a TCP server (using ports) so client can connect to it via other device and send requests and server responds with data.
I followed the Socket example on :Microsoft site, and got sample code working (in which server and client are both in same app)
I changed IP addresses and ports so i could use apps on 2 different machines with direct connection, I also made separate simple client application, using sample code from Here
Now problem is as follows: UWP app can successfully communicate with its own client method provided by Microsoft's sample, but is unable to communicate with console client program I made and was running on other. UWP can indeed connect with client and also send data, but it cannot receive data, the function streamReader.ReadLineAsync(); will wait infinitely long and that's all.
How do i make UWP app get the message client is sending and what i might be doing wrong ?
public sealed partial class MainPage : Page
{
static string PORT_NO = "1300";
const string SERVER_IP = "192.168.0.10";
public MainPage()
{
this.InitializeComponent();
outputText.Text = "Helloo";
StartConnection(SERVER_IP, PORT_NO);
//StartClient();
}
public async void StartConnection(string net_aadress, string port_nr)
{
try
{
var streamSocketListener = new StreamSocketListener();
// The ConnectionReceived event is raised when connections are received.
streamSocketListener.ConnectionReceived += this.StreamSocketListener_ConnectionReceived;
// Start listening for incoming TCP connections on the specified port. You can specify any port that's not currently in use.
await streamSocketListener.BindServiceNameAsync(port_nr);
outputText.Text = "server is listening...";
}
catch (Exception ex)
{
Windows.Networking.Sockets.SocketErrorStatus webErrorStatus = Windows.Networking.Sockets.SocketError.GetStatus(ex.GetBaseException().HResult);
outputText.Text = (webErrorStatus.ToString() != "Unknown" ? webErrorStatus.ToString() : ex.Message);
}
}
private async void StreamSocketListener_ConnectionReceived(Windows.Networking.Sockets.StreamSocketListener sender, Windows.Networking.Sockets.StreamSocketListenerConnectionReceivedEventArgs args)
{
string request = "password";
string second;
/*
using (var streamReader = new StreamReader(args.Socket.InputStream.AsStreamForRead()))
{
request = await streamReader.ReadLineAsync();
}
*/
//await this.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () => this.serverListBox.Items.Add(string.Format("server received the request: \"{0}\"", request)));
// Echo the request back as the response.
using (Stream outputStream = args.Socket.OutputStream.AsStreamForWrite())
{
using (var streamWriter = new StreamWriter(outputStream))
{
await streamWriter.WriteLineAsync(request);
await streamWriter.FlushAsync();
}
}
using (var streamReader = new StreamReader(args.Socket.InputStream.AsStreamForRead()))
{
second = await streamReader.ReadLineAsync();
}
using (Stream outputStream = args.Socket.OutputStream.AsStreamForWrite())
{
using (var streamWriter = new StreamWriter(outputStream))
{
await streamWriter.WriteLineAsync(second);
await streamWriter.FlushAsync();
}
}
//await this.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () => this.serverListBox.Items.Add(string.Format("server sent back the response: \"{0}\"", request)));
sender.Dispose();
//await this.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () => this.serverListBox.Items.Add("server closed its socket"));
}
private async void StartClient()
{
try
{
// Create the StreamSocket and establish a connection to the echo server.
using (var streamSocket = new Windows.Networking.Sockets.StreamSocket())
{
// The server hostname that we will be establishing a connection to. In this example, the server and client are in the same process.
var hostName = new Windows.Networking.HostName("localhost");
//this.clientListBox.Items.Add("client is trying to connect...");
await streamSocket.ConnectAsync(hostName, PORT_NO);
//this.clientListBox.Items.Add("client connected");
// Send a request to the echo server.
string request = "Hello, World!";
using (Stream outputStream = streamSocket.OutputStream.AsStreamForWrite())
{
using (var streamWriter = new StreamWriter(outputStream))
{
await streamWriter.WriteLineAsync(request);
await streamWriter.FlushAsync();
}
}
//this.clientListBox.Items.Add(string.Format("client sent the request: \"{0}\"", request));
// Read data from the echo server.
string response;
using (Stream inputStream = streamSocket.InputStream.AsStreamForRead())
{
using (StreamReader streamReader = new StreamReader(inputStream))
{
response = await streamReader.ReadLineAsync();
}
}
await Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(Windows.UI.Core.CoreDispatcherPriority.Normal,
() =>
{
outputText.Text = "Client got back " + response;
}
);
}
//this.clientListBox.Items.Add("client closed its socket");
}
catch (Exception ex)
{
Windows.Networking.Sockets.SocketErrorStatus webErrorStatus = Windows.Networking.Sockets.SocketError.GetStatus(ex.GetBaseException().HResult);
//this.clientListBox.Items.Add(webErrorStatus.ToString() != "Unknown" ? webErrorStatus.ToString() : ex.Message);
}
}
}
Here is source code for Client application:
{
class Program
{
const int PORT_NUMBER = 1300;
const string SERVER_IP = "192.168.0.10";
static void Main(string[] args)
{
string textToSend = DateTime.Now.ToString();
string password = "Madis on loll";
string receiveddata;
try
{
Console.WriteLine("Client progrm started");
TcpClient client = new TcpClient(SERVER_IP, PORT_NUMBER);
NetworkStream nwStream = client.GetStream();
//System.Threading.Thread.Sleep(500);
//see, how long is packet
byte[] bytesToRead = new byte[client.ReceiveBufferSize];
int bytesRead = nwStream.Read(bytesToRead, 0, client.ReceiveBufferSize);
Console.WriteLine("Received : " + Encoding.ASCII.GetString(bytesToRead, 0, bytesRead));
byte[] password2 = ASCIIEncoding.ASCII.GetBytes(password);
Console.WriteLine("Sending : " + password);
nwStream.Write(password2, 0, password2.Length); //sending packet
byte[] receiveddata2 = new byte[client.ReceiveBufferSize];
int receiveddatalength = nwStream.Read(receiveddata2, 0, client.ReceiveBufferSize);
Console.WriteLine("Received : " + Encoding.ASCII.GetString(receiveddata2, 0, bytesRead));
}
catch (Exception ex)
{
Console.WriteLine("Connection error");
}
}
}
}
Found answer myself: main problem is with ReadLineAsync() in Server program: it waits and collects all the stream until it gets end of line character. In this case end of line was never sent and therefore server kept waiting infinitely.
Simplest fix was on Client side by simply adding end of line at the end of packet, like this:
before:
byte[] password2 = ASCIIEncoding.ASCII.GetBytes(password);
Console.WriteLine("Sending : " + password);
nwStream.Write(password2, 0, password2.Length); //sending packet
after:
byte[] newLine = Encoding.ASCII.GetBytes(Environment.NewLine);
byte[] password2 = ASCIIEncoding.ASCII.GetBytes(password);
Console.WriteLine("Sending : " + password);
nwStream.Write(password2, 0, password2.Length); //sending packet
nwStream.Write(newLine,0,newLine.Length);
Also 1 thing worth mentioning: current StreamSocketListener_ConnectionReceived is able to send only once, then it sets outputStream.CanWrite to false.
This can be solved by removing using() from writing and reading functions, like this:
before:
PS! Manually flushing is also replaced with autoflush.
using (Stream outputStream = args.Socket.OutputStream.AsStreamForWrite())
{
using (var streamWriter = new StreamWriter(outputStream))
{
await streamWriter.WriteLineAsync(request);
await streamWriter.FlushAsync();
}
}
after:
Stream outputStream = args.Socket.OutputStream.AsStreamForWrite();
var streamWriter = new StreamWriter(outputStream);
streamWriter.AutoFlush = true;
await streamWriter.WriteLineAsync(request);
Hope it helps someone someday.

Async TCPClient missing replies from server

I'm trying to implement an async TCP client that sends messages from a queue and listens to the response.
some of the server replies are lost (for example send 7 messages and get only 4 replies) and I don't understand why.
This is not a server issue, since the synchronize version I tested works just fine.
ConcurrentQueue<byte[]> msgQueue = new ConcurrentQueue<byte[]>();
public void Connect()
{
try
{
tcpclnt = new TcpClient();
Console.WriteLine("Connecting.....");
Task.Factory.StartNew(() =>
{
IAsyncResult res = tcpclnt.BeginConnect(_ip, _port, null, null);
if (!res.AsyncWaitHandle.WaitOne(CONNECTION_TIMEOUT_SEC * 1000))
{
tcpclnt.Close();
throw new ApplicationException("timed out trying to connect");
}
tcpclnt.EndConnect(res);
Receive();
byte[] message = null;
while (true)
{
message = null;
msgQueue.TryDequeue(out message);
if (message != null)
{
Stream stm = tcpclnt.GetStream();
Console.WriteLine("Transmitting..... " + Thread.CurrentThread.ManagedThreadId);//for debug
stm.Write(message.ToArray(), 0, message.ToArray().Length);
Receive();
}
}
});
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
}
}
//will be called from outside
public void SendMessage(byte[] msg)
{
Console.WriteLine("SendMessage..... " + Thread.CurrentThread.ManagedThreadId);//for debug
msgQueue.Enqueue(msg);
}
private void Receive()
{
SocketError error;
byte[] buffer = new byte[MAX_BUFFER_SIZE];
tcpclnt.Client.BeginReceive(buffer, 0, MAX_BUFFER_SIZE, SocketFlags.None, out error, new AsyncCallback(ReceiveHandler), buffer);
}
private void ReceiveHandler(IAsyncResult ar)
{
System.Console.WriteLine("ReceiveHandler " + Thread.CurrentThread.ManagedThreadId); //for debug
//End current async receive
int bytesRead = tcpclnt.Client.EndReceive(ar);
byte[] resultBuffer = (byte[]) ar.AsyncState;
// do a lot of things with resultBuffer
}

Socket - Java Client, C# Server

I am making a program in 2 parts.
Part 1: C# server-socket Application running on PC, listening for commands, and acts accordingly.
Part 2: Java client-socket application running on phone, that sends a command to the pc, when a button is pressed.
Currently, i can send commands from the client to the server, and its all good.
But my problem is this: When i send a specific command to the server, i want the server to reply to the client, and the client to read that reply.
Thing just is, when the client tries to read, it time-outs.
Java client program:
class ClientThread implements Runnable
{
public void run()
{
try
{
Socket socket = new Socket(serverIpAddress, serverPort);
socket.setSoTimeout(5000);
while (true)
{
try
{
PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())), true);
Log.d("Nicklas", "Out it goes");
out.println(Command);
if (Command == "CMD:GetOptions<EOF>")
{
Log.d("Nicklas", "Getting options");
try
{
Log.d("Nicklas", "Line 1");
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
Log.d("Nicklas", "Line 2");
String answer = in.readLine();
Log.d("Nicklas", "answer = " + answer );
}
catch (Exception ee)
{
Log.d("Nicklasasasas", ee.toString());
}
}
break;
}
catch (Exception e)
{
Log.d("Nicklas", "CAE = " + e.toString());
break;
}
}
socket.close();
}
catch (ConnectException ee)
{
Log.d("Nicklas", "Kunne ikke forbinde");
}
catch (Exception e)
{
Log.d("Nicklasssssss", e.toString());
}
}
}
This is called with:
Thread cThread = new Thread(new ClientThread());
cThread.start();
And uses the global variable "Command", which will contain different information, depending on what button was pressed.
The program fails on the line "String answer = in.readline();" with the exception "java.net.SocketTimeoutException".
This is the C# Server part of the program:
private void ListenForClients()
{
this.tcpListener.Start();
while (true)
{
//blocks until a client has connected to the server
TcpClient client = this.tcpListener.AcceptTcpClient();
//create a thread to handle communication
//with connected client
Thread clientThread = new Thread(new ParameterizedThreadStart(HandleClientComm));
clientThread.Start(client);
}
}
private void HandleClientComm(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
{
//a socket error has occured
break;
}
if (bytesRead == 0)
{
//the client has disconnected from the server
break;
}
//message has successfully been received
ASCIIEncoding encoder = new ASCIIEncoding();
//System.Diagnostics.Debug.WriteLine(encoder.GetString(message, 0, bytesRead));
string Input = (encoder.GetString(message, 0, bytesRead));
Input = Input.Trim();
object[] obj = new object[1];
obj[0] = Input;
if (Input == "CMD:GetOptions<EOF>")
{
try
{
byte[] buffer = encoder.GetBytes("CMD:Accepted");
clientStream.Write(buffer, 0, buffer.Length);
clientStream.Flush();
MessageBox.Show("Client program asked for reply");
}
catch (Exception e)
{
MessageBox.Show("Oh it no work!: " + e.ToString());
}
}
else
{
Udfor(Input);
}
}
tcpClient.Close();
}
Called with the following, in the Form1()
this.tcpListener = new TcpListener(IPAddress.Any, 4532);
this.listenThread = new Thread(new ThreadStart(ListenForClients));
this.listenThread.Start();
The C# Server seems to work fine, and does show the messagebox "client program asked for reply"
Anyone who can spot the error?
I figured it out!
The problem was the C#. When the server sent back the command "CMD:Accepted", it never closed the socket, so the android application had no idea of telling if it was done reading! Closing the socket right after flushing + of course not closing it again if i already did, did the trick!

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