I'm trying to use Raspberry Pi and a 7" touchscreen to create an Assetto Corsa dashboard, coding with vb on the Universal Windows Platform.
I'm experiencing A LOT of problems with this platform because objects are very different from .net and I find the Microsoft's logic very strange.
However, I try to explain the problem: Assetto Corsa have his own telemetry that when the user starts a session begins to send some data to the connected clients on port 9996, UDP Protocol.
Really, the game is not so simple because to "bind" a client to the server there is a "procedure" that consists in:
The client have to send a structured data containing 3 ints ("110")
The server responds sending to the client some data containing the
track name, the player name and others
The client must send another structured data, this time containing
"111" After this, client and server are "handshaked" and the server
start sending continuous data to the client containing a lot of data
concerning the car's physics.
Here is a more accurate description of the handshaking protocol: Assetto corsa UDP Telemetry documentation
Since those are the first time that I approach UPD communication, I would have been sure to have correctly understood how it works, so I wrote this python script:
from socket import *
from struct import *
serverName='127.0.0.1'
serverPort = 9996
clientSocket = socket(AF_INET,SOCK_DGRAM)
message=pack('iii',1,1,0)
clientSocket.sendto(message, (serverName, serverPort))
messageback, ipAddress=clientSocket.recvfrom(1024)
print 'received'
pktformat='408c'
n = calcsize(pktformat)
print n
#n = len(messageback)
#print n
backString = unpack(pktformat, messageback)
#print backString[1,2,3,4,5,6,7,8,9,10]
#print "fffffff"
message=pack('iii',1,1,1)
clientSocket.sendto(message, (serverName, serverPort))
i=0
while 1:
pktformat='4chfff??????fffhhhhfffffhf4f4f4f4f4f4f4f4f4f4f4f4f4f4fff5f'
messageback, ipAddress =clientSocket.recvfrom(16384)
n = calcsize(pktformat)
print n
n = len(messageback)
print n
backString = unpack(pktformat, messageback)
print backString
i+=1
clientSocket.close()
Everything works but Python GUIs are not so good to see so I would move to VS+VB+UWP+WIN10IoT.
Dim s As String = "110"
Dim byteCommand As Byte() = Encoding.ASCII.GetBytes(s)
Dim writer As New DataWriter(listener.OutputStream)
writer.WriteBytes(byteCommand)
Try
Await listener.ConnectAsync(hostname, "9996")
Await writer.StoreAsync()
Catch ex As Exception
testo = ex.Message
refreshTb()
End Try
With this code I'm able to receive THE FIRST communication from server, so I repeat the code sending "111":
Private Async Sub HandShake(inStream As IBuffer)
If handShaked Then
Exit Sub
End If
handShaked = True
Dim writer As New DataWriter(listener.OutputStream)
Dim s As String = "111"
Dim byteCommand As Byte() = Encoding.ASCII.GetBytes(s)
writer.WriteBytes(byteCommand)
Await writer.StoreAsync()
testo = "hand-shaked!"
End Sub
After this, nothing happens.
I tried:
1. Send data as string, instead of byte(). Nothing changed
2. Send "XXX" instead of "110": I expected to not receive nothing but I received the same as when I send "110"!!!
So I'm starting to think that the I'm not correctly converting "110" so I'm sending a kind of data to server that it's not able to understand.
Any ideas?
Related
I have a simple TCP/IP HTML server. To access this HTML server the user needs to type the IP address of the machine the HTML server is running on also, if the user types a faulty URL as long as it starts with the correct IP-address followed by a forward slash (example: 123.456.789.0/FaultyText) it also works.
My understanding is that if I type in a web browsers address bar it broadcasts that text-string till some server says "hey I recognize this, let me react upon it" meaning (according to my understanding) the opposite is also true if a text-string is broadcast which the server does not recognize it says "This I cannot identify, I'll pass reacting upon it". This would mean the text-string must always be read to know it's at the right destination or not.
So how come if I type something random in the URL address bar, the following code snippet won't reference to it in its HTTP headers Host:, or Refrence: sections (or anywhere else for that matter of fact)?
#Region "Start Server"
Dim MyIp As String
Dim MyPort As String
Try
'If Not MyNetworkPortBase64Plain = Nothing Then
' MyIp = MyNetworkIpBase64Plain
'Else
' Dim MyComputerName As String = Dns.GetHostName()
' MyIp = Dns.GetHostByName(MyComputerName).AddressList(0).ToString()
'End If
If Not MyNetworkPortBase64Plain = Nothing Then
MyPort = MyNetworkPortBase64Plain
Else
MyPort = "8080"
End If
MyIp = (IPAddress.Any).ToString
MyHtmlServer = New TcpListener(IPAddress.Parse(MyIp), MyPort)
MyHtmlServer.Start()
Threading.ThreadPool.QueueUserWorkItem(AddressOf MyNewClientSub)
#Region "Server Start/ Stop Button"
#Region "Get/ Collect Incoming Bytes"
Dim MyNetworkStream As NetworkStream = MyClient.GetStream()
Dim MyReceivingBytes(100000) As Byte
MyNetworkStream.Read(MyReceivingBytes, 0, MyReceivingBytes.Length)
Dim MyIncommingRequests As String = Encoding.ASCII.GetString(MyReceivingBytes)
Dim webClient As New System.Net.WebClient
MsgBox(MyIncommingRequests)
#End Region
How can I catch all the URL requests made?
I am trying to write an asynchronous TCP client with VB.NET to communicate with a thermal printer (Intermec Px4e), but I am facing an issue regarding the way I receive the data from it.
Previously I was using a synchronous client, but I had the problem regarding the response not coming instantly from the printer, so after sending data and then checking for available bytes I was able to read only the first bytes of the response.
This is the synchronous client I am actually using:
Private Function sendBytesEthernet(ByVal data As Byte(), ByVal withResponse As Boolean) As PrinterPacket(Of Byte())
Dim socketStatus As Net.Sockets.SocketError
Dim response As New PrinterPacket(Of Byte()) With {.StatusCode = CommandStatusCode.ERR, _
.Response = String.Empty, _
.Data = data}
Try
If Me.oggettoSocket.Client.Poll(2000, Sockets.SelectMode.SelectWrite) Then
Me.oggettoSocket.Client.Send(data, 0, data.Length, 0, socketStatus)
Else
Throw New Exception(socketStatus.ToString())
End If
If withResponse Then
Dim bytesAvailable As UInteger = Me.oggettoSocket.Available
If bytesAvailable > 0 Then
Dim dataBuffer(bytesAvailable - 1) As Byte
Dim bytesReceived As UInteger = Me.oggettoSocket.Client.Receive(dataBuffer, 0, dataBuffer.Length, Sockets.SocketFlags.None, socketStatus)
If socketStatus = Sockets.SocketError.Success Then
If bytesReceived > 0 Then
response.Response = System.Text.Encoding.UTF8.GetString(dataBuffer)
response.StatusCode = CommandStatusCode.OK
Return response
End If
Else
Throw New Exception(socketStatus.ToString())
End If
End If
End If
If socketStatus = Sockets.SocketError.Success Then
response.StatusCode = CommandStatusCode.OK
Else
Throw New Exception(socketStatus.ToString())
End If
Catch ex As Exception
Select Case ex.Message
Case "ConnectionReset"
Me.oggettoSocket.Client.Disconnect(True)
Me.openSocket()
End Select
response.Response = ex.Message
End Try
Return response
End Function
What happens is that If send a command to the printer that involves a big response from it, I receive the full response splitted in several packets, so with this function I am only able to read the first packet.
For example:
I send to the printer the command to list all the fonts available (FONTS[CRLF])
The printer responds, but it sends the first 54 bytes and then truncates the list.
The printer sends the second packet, this time 1560 bytes long, but it still truncates the list.
Lastly the printer completes the list with last 25 bytes.
Basically with my function I am only able to read the first 54 bytes, unless I don't use a loop to check the availability on the receive buffer in conjunction with a Thread.Sleep() call, since the client is synchronous and I have to wait for the printer to send every packet, but I find this method really inefficient.
At this point I concluded that I had to move to an asynchronous approach, due to the nature of the TCP protocol. I copied an example of async client on the MSDN and it works, but it doesn't fit my use case. Why?
Because I actually have a thread that constantly communicate with the printer through the socket, and I open the connection when the thread starts and close it when the thread ends. If use, for example, the BeginReceive callback used in the MSDN example, that call will never end until I close the connection client side. This cannot take place, since I keep the connection open to the printer and I can't establish a new TCP connection for every thread cycle (that would be a waste in terms of network traffic).
I hope I have explained the problem well.
Hello I am trying to create a chat bot for my twitch channel in Visual Basic. I did some research and I found this code:
Public Class My_IRC
Private _sServer As String = String.Empty '-- IRC server name
Private _sChannel As String = String.Empty '-- the channel you want to join (prefex with #)
Private _sNickName As String = String.Empty '-- the nick name you want show up in the side bar
Private _lPort As Int32 = 6667 '-- the port to connect to. Default is 6667
Private _bInvisible As Boolean = False '-- shows up as an invisible user. Still working on this.
Private _sRealName As String = "nodibot" '-- More naming
Private _sUserName As String = "nodi_the_bot" '-- Unique name so of the IRC network has a unique handle to you regardless of the nickname.
Private _tcpclientConnection As TcpClient = Nothing '-- main connection to the IRC network.
Private _networkStream As NetworkStream = Nothing '-- break that connection down to a network stream.
Private _streamWriter As StreamWriter = Nothing '-- provide a convenient access to writing commands.
Private _streamReader As StreamReader = Nothing '-- provide a convenient access to reading commands.
Public Sub New(ByVal server As String, ByVal channel As String, ByVal nickname As String, ByVal port As Int32, ByVal invisible As Boolean)
_sServer = server
_sChannel = channel
_sNickName = nickname
_lPort = port
_bInvisible = invisible
End Sub
Public Sub Connect()
'-- IDENT explained:
'-- -- When connecting to the IRC server they will send a response to your 113 port.
'-- -- It wants your user name and a response code back. If you don't some servers
'-- -- won't let you in or will boot you. Once verified it drastically speeds up
'-- -- the connecting time.
'-- -- -- http://en.wikipedia.org/wiki/Ident
'-- Heads up - when sending a command you need to flush the writer each time. That's key.
Dim sIsInvisible As String = String.Empty
Dim sCommand As String = String.Empty '-- commands to process from the room.
'-- objects used for the IDENT response.
Dim identListener As TcpListener = Nothing
Dim identClient As TcpClient = Nothing
Dim identNetworkStream As NetworkStream = Nothing
Dim identStreamReader As StreamReader = Nothing
Dim identStreamWriter As StreamWriter = Nothing
Dim identResponseString As String = String.Empty
Try
'-- Start the main connection to the IRC server.
Console.WriteLine("**Creating Connection**")
_tcpclientConnection = New TcpClient(_sServer, _lPort)
_networkStream = _tcpclientConnection.GetStream
_streamReader = New StreamReader(_networkStream)
_streamWriter = New StreamWriter(_networkStream)
'-- Yeah, questionable if this works all the time.
If _bInvisible Then
sIsInvisible = 8
Else
sIsInvisible = 0
End If
'-- Send in your information
Console.WriteLine("**Setting up name**")
_streamWriter.WriteLine(String.Format("USER {0} {1} * :{2}", _sUserName, sIsInvisible, _sRealName))
_streamWriter.Flush()
'-- Create your nickname.
Console.WriteLine("**Setting Nickname**")
_streamWriter.WriteLine(String.Format(String.Format("NICK {0}", _sNickName)))
_streamWriter.Flush()
'-- Tell the server you want to connect to a specific room.
Console.WriteLine("**Joining Room**")
_streamWriter.WriteLine(String.Format("JOIN {0}", _sChannel))
_streamWriter.Flush()
'-- By now the IDENT should be sent to your port 113. Listen to it, grab the text,
'-- and send a response.
'-- Idents are usually #### , ####
'-- That is four digits, a space, a comma, and four more digits. You need to send
'-- this back with your user name you connected with and your system.
identListener = New TcpListener(IPAddress.Any, 113)
identListener.Start()
identClient = identListener.AcceptTcpClient
identListener.Stop()
Console.WriteLine("ident connection?")
identNetworkStream = identClient.GetStream
identStreamReader = New StreamReader(identNetworkStream)
identResponseString = identStreamReader.ReadLine
Console.WriteLine("ident got: " + identResponseString)
identStreamWriter = New StreamWriter(identNetworkStream)
'-- The general format for the IDENT response. You can use UNIX, WINDOWS VISTA, WINDOWS XP, or what ever your system is.
identStreamWriter.WriteLine(String.Format("{0} : USERID : WINDOWS 7 : {1}", identResponseString, _sUserName))
identStreamWriter.Flush()
'-- By now you should be connected to your room and visible to anyone else.
'-- If you are receiving errors they are pretty explicit and you can maneuver
'-- to debuggin them.
'--
'-- What happens here is the command processing. In an infinite loop the bot
'-- read in commands and act on them.
While True
sCommand = _streamReader.ReadLine
Console.WriteLine(sCommand)
'-- Not the best method but for the time being it works.
'--
'-- Example of a command it picks up
' :nodi123!nodi12312#ipxxx-xx.net PRIVMSG #nodi123_test :? hola!
'-- You can extend the program to better read the lines!
Dim sCommandParts(sCommand.Split(" ").Length) As String
sCommandParts = sCommand.Split(" ")
'-- Occasionally the IRC server will ping the app. If it doesn't respond in an
'-- appropriate amount of time the connection is closed.
'-- How does one respond to a ping, but with a pong! (and the hash it sends)
If sCommandParts(0) = "PING" Then
Dim sPing As String = String.Empty
For i As Int32 = 1 To sCommandParts.Length - 1
sPing += sCommandParts(i) + " "
Next
_streamWriter.WriteLine("PONG " + sPing)
_streamWriter.Flush()
Console.WriteLine("PONG " + sPing)
End If
'-- With my jank split command we want to look for specific commands sent and react to them!
'-- In theory this should be dumped to a method, but for this small tutorial you can see them here.
'-- Also any user can input this. If you want to respond to commands from you only you would
'-- have to extend the program to look for your non-bot-id in the sCommandParts(0)
If sCommandParts.Length >= 4 Then
'-- If a statement is proceeded by a question mark (the semi colon's there automatically)
'-- then repeat the rest of the string!
If sCommandParts(3).StartsWith(":?") Then
Dim sVal As String = String.Empty
Dim sOut As String = String.Empty
'-- the text might have other spaces in them so concatenate the rest of the parts
'-- because it's all text.
For i As Int32 = 3 To sCommandParts.Length - 1
sVal += sCommandParts(i)
sVal += " "
Next
'-- remove the :? part.
sVal = sVal.Substring(2, sVal.Length - 2)
'-- Trim for good measure.
sVal = sVal.Trim
'-- Send the text back out. The format is they command to send the text and the room you are in.
sOut = String.Format("PRIVMSG {0} : You said '{1}'", _sChannel, sVal)
_streamWriter.WriteLine(sOut)
_streamWriter.Flush()
End If
'-- If you don't quit the bot correctly the connection will be active until a ping/pong is failed.
'-- Even if your programming isn't running!
'-- To stop that here's a command to have the bot quit!
If sCommandParts(3).Contains(":!Q") Then
' Stop
_streamWriter.WriteLine("QUIT")
_streamWriter.Flush()
Exit Sub
End If
End If
End While
Catch ex As Exception
'-- Any exception quits the bot gracefully.
Console.WriteLine("Error in Connecting. " + ex.Message)
_streamWriter.WriteLine("QUIT")
_streamWriter.Flush()
Finally
'-- close your connections
_streamReader.Dispose()
_streamWriter.Dispose()
_networkStream.Dispose()
End Try
End Sub
End Class
and
Imports System
Imports System.Net
Imports System.Net.Sockets
Imports System.IO
Public Sub Main()
Dim foo As New My_IRC("irc.freenode.net", "#nodi123_test", "nodime", 6667, False)
foo.Connect()
End Sub
But I can not succeed to connect using a password because it is simply to hard for me as a beginner. (You can either set a password or use the command /server irc.twitch.tv 6667 oauth:AUTHKEY) so my question is, is there a way to set the password in the code I posted? Or is there another stable way to use IRC in Visual Basic which allows me to set a server password? Let me know, thanks.
Your first stop should be the IRC RFC documents, RFC 1459 and 2812. From the snippet of code you provided, your IRC client does not implement the PASS message -- see section 4.1.1 of RFC 1459.
4.1.1 Password message
Command: PASS Parameters: <password>
The PASS command is used to set a 'connection password'. The
password can and must be set before any attempt to register the
connection is made. Currently this requires that clients send a PASS
command before sending the NICK/USER combination and servers must
send a PASS command before any SERVER command. The password supplied
must match the one contained in the C/N lines (for servers) or I
lines (for clients). It is possible to send multiple PASS commands
before registering but only the last one sent is used for
verification and it may not be changed once registered. Numeric
Replies:
ERR_NEEDMOREPARAMS ERR_ALREADYREGISTRED
Example:
PASS secretpasswordhere
It should be relatively easy to implement:
**Console.WriteLine("**Setting Password**")
_streamWriter.WriteLine(String.Format(String.Format("PASS {0}", whateverVariableYouChooseToHoldThePassword)))
_streamWriter.Flush()**
'-- Send in your information
Console.WriteLine("**Setting up name**")
_streamWriter.WriteLine(String.Format("USER {0} {1} * :{2}", _sUserName, sIsInvisible, _sRealName))
_streamWriter.Flush()
I'll take this opportunity to mention that I wrote an IRC library a while back that may help you, at least as a reference point for how IRC behaves. I implemented a decent portion of RFC 1459 before I lost interest. Interestingly enough, my IRC library doesn't support sending the PASS message either (although it would be similarly easy to add support).
My library could theoretically be of use to you as-is, but I don't think it's production ready, so to speak.
I am new to programming in vb.net. I have come a long ways in my development and understanding of vb, but there is one hurtle I can not seem to fix. I am hosting an ftp server on my pc and I am making an app for it to connect to my server and download files. The problem with all the sample code is that everyone ASSUMES the server WILL be ONLINE. My pc may not be running 24/7 and I also may not have the ftp service running.In the first case it shouldnt even register that it is connected. In the second case, it WILL say that is connected b/c the pc is on, but it will return that the machine ou are trying to connect to is actively refusing the connection. Is there a way to TRULY check if the program is indeed connected to the server WITHOUT generating a bunch of Exceptions in the debugger? All I want is a call like:
Dim ftponline As Boolean = False 'Set default to false
ftponline = checkftp()
If ftponline Then
'continue program
Else
'try a different server
End If
So it would be a function called checkftp that returns a boolean value of true or false.
Here is my info:
Using Visual Studio 2010 Pro
Using .Net framework 4
Can anyone help?
Thanks!
I have tried the rebex ftp pack as well as the Ultimate FTP Pack.
Here is the updated code:
Public Function CheckConnection(address As String) As Boolean
Dim logonServer As New System.Net.Sockets.TcpClient()
Try
logonServer.Connect(address, 21)
Catch generatedExceptionName As Exception
MessageBox.Show("Failed to connect to: " & address)
End Try
If logonServer.Connected Then
MessageBox.Show("Connected to: " & address)
Return True
logonServer.Close()
Else
Return False
End If
End Function
Public Sub ConnectFtp()
types.Clear()
models.Clear()
ListBox1.Items.Clear()
ListBox2.Items.Clear()
TextBox2.Clear()
Dim request As New Rebex.Net.Ftp
If CheckConnection(*) Then
Dim tempString As String()
request.Connect(*)
request.Login(*, *)
request.ChangeDirectory("/atc3/HD_Models")
Dim list As Array
list = request.GetNameList()
Dim item As String = ""
For Each item In list
tempString = item.Split(New Char() {" "c})
If types.Contains(tempString(0)) = False Then
types.Add(tempString(0))
End If
If models.Contains(item) = False Then
models.Add(item)
End If
Next
request.Disconnect()
request.Dispose()
ElseIf CheckConnection(*) Then
request.Connect(*)
request.Login(*, *)
request.ChangeDirectory(*)
Dim list2 As Array
list2 = request.GetNameList()
Dim item2 As String = ""
Dim tempString2 As String()
For Each item2 In list2
MessageBox.Show(item2)
tempString2 = item2.Split(New Char() {" "c})
If types.Contains(tempString2(0)) = False Then
types.Add(tempString2(0))
End If
If models.Contains(item2) = False Then
models.Add(item2)
End If
Next
request.Disconnect()
request.Dispose()
End If
End Sub
No matter what I do, the second server will not connect. I even put a messagebox to show what items were being returned in the second server, but there are no messageboxes apearing when I run the program with my server offline. Is there anyone who can help?
If your code is designed with proper exception catching, it shouldn't be generating a "bunch" of exceptions. The first exception you catch should be your indication that the connection failed and your code should cease attempting to communicate at that point. If for some reason you really need to check the connectivity before attempting the FTP connection, you should be able to simply attempt to synchronously open a TCP socket to the FTP server's port. If that works, it's up and running.
You could simply open a socket to the server's IP address on Port 21 (assuming default FTP port).
I'm not much of a VB.Net programmer, but here's a link to sample code:
http://vb.net-informations.com/communications/vb.net_Client_Socket.htm
If you can establish the socket connection, you know that something is listening on that port (though you have not yet proven it's an FTP server, or that it will accept your login credentials...).
If you wish to simply avoid exceptions in the debugger, you could place the connection code in a method and apply the DebuggerHidden attribute to that method.
I am not a software programmer but I have a task to create a TCP Server (a program that is listening on its network card interfaces for incoming data streams).
I have searched on the internet and I found that I can use two methods: Socket or TCPListener class.
I have created an example for the Socket class, but I was wondering how I can test it?
If another computer in the network sends some string data to the listener computer, then the message should be displayed.
Here is the example from Microsoft that I am using for the TCP server using a Socket:
Public Shared Sub Main()
' Data buffer for incoming data.
Dim data = nothing
Dim bytes() As Byte = New [Byte](1024) {}
Dim ipAddress As IPAddress = ipAddress.Any
Dim localEndPoint As New IPEndPoint(ipAddress, 0)
Dim intI As Integer = 0
'Display the NIC interfaces from the listener
For Each ipAddress In ipHostInfo.AddressList
Console.WriteLine("The NIC are {0}", ipHostInfo.AddressList(intI))
intI += 1
Next
Console.WriteLine("You are listening on {0}",localEndPoint)
' Create a TCP/IP socket.
Dim listener As New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
' Bind the socket to the local endpoint and
' listen for incoming connections.
Try
listener.Bind(localEndPoint)
listener.Listen(200)
Catch e As SocketException
Console.WriteLine("An application is alreading using that combination of ip adress/port", e.ErrorCode.ToString)
End Try
' Start listening for connections.
While True
Console.WriteLine("Waiting for a connection...")
' Program is suspended while waiting for an incoming connection.
Dim handler As Socket = listener.Accept()
data = Nothing
' An incoming connection needs to be processed.
While True
bytes = New Byte(1024) {}
Dim bytesRec As Integer = handler.Receive(bytes)
data += Encoding.ASCII.GetString(bytes, 0, bytesRec)
Console.WriteLine("The string captured is {0}", data)
If data.IndexOf("something") > -1 Then
Exit While
End If
End While
' Show the data on the console.
Console.WriteLine("Text received : {0}", data)
' Echo the data back to the client.
Dim msg As Byte() = Encoding.ASCII.GetBytes(data)
handler.Shutdown(SocketShutdown.Both)
handler.Close()
End While
End Sub
End Class
Am I on the right lead?
Thanks
Later Edit:
I have used that code in a Console Application created with Visual Studio and I want to check the scenario when a device is sending some string message through the network.
E.g:
I have two devices :Computer A, computer B connected through LAN
I have tried this command : telnet computerA port ( from computer B) but nothing is displayed in the TCP server running from computer A.
telnet 192.168.0.150 3232
I also made a TCP client for testing (derived from the Microsoft example):
Public Class SynchronousSocketClient
Public Shared Sub Main()
' Data buffer for incoming data.
Dim bytes(1024) As Byte
Dim ipHostInfo As IPHostEntry = Dns.GetHostEntry(Dns.GetHostName())
Dim ipAddress As IPAddress = ipHostInfo.AddressList(0)
Dim remoteEP As New IPEndPoint(ipAddress, 11000)
' Create a TCP/IP socket.
Dim sender As New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
' Connect the socket to the remote endpoint.
sender.Connect(remoteEP)
Console.WriteLine("Socket connected to {0}", _
sender.RemoteEndPoint.ToString())
' Encode the data string into a byte array.
Dim msg As Byte() = _
Encoding.ASCII.GetBytes("This is a test<EOF>")
' Send the data through the socket.
Dim bytesSent As Integer = sender.Send(msg)
' Receive the response from the remote device.
Dim bytesRec As Integer = sender.Receive(bytes)
Console.WriteLine("Echoed test = {0}", _
Encoding.ASCII.GetString(bytes, 0, bytesRec))
' Release the socket.
sender.Shutdown(SocketShutdown.Both)
sender.Close()
Console.ReadLine()
End Sub
End Class 'SynchronousSocketClient
But it does not work because of the PORT setting.
If in the TCP Server I have "Dim localEndPoint As New IPEndPoint(ipAddress, 0)" then the client crashes, but if I change the port from any (0) to 11000 for example, the client works fine.
Do you know why?
Later edit 2:
Maybe I should have started with this question: Which method is recommended for my scope - asynchronous or synchronous method?
Yes, you are on the right path.
The next thing to do is to introduce message detection since TCP is stream based and not message based like UDP. This means that TCP might decide to send two of your messages in the same packet (so that one socket.Recieve will get two messages) or that it will split up your message into two packets (thus requiring you to use two socket.Recieve to get it).
The two most common ways to create message detection is:
Create a fixed size header which includes message size
Create a delimiter which is appended to all messages.
Your "server" isn't listening on a set port, so you'll need to pay attention to the "You are listening on" message that appears. Then, from another machine on the network, telnet the.ip.add.ress port. (This may require installing "telnet client", or enabling it in the Programs and Features stuff, or whatever.)
Side note...if you actually intend for this to be a server of some sort, you'll want to decide what port you want to use, so that other computers can find your service. Most people won't be able to read your screen to figure out where to connect. :)
As for your "client"...when you connect to another computer, you don't just "pick a port" (which is what a port number of 0 means in an endpoint). You need to know what port the server uses. (Reread what i said in the previous paragraph. A program running on another computer has no idea what port to use to connect to the server -- any server could be running on any port.) You need to pick a port number for the server (say, 11000...good as any, really) rather than letting it use port 0.