client and server - What have i missed

[robertuk702]

The code below is program one - the client

[SIZE=2][COLOR=#0000ff]Class[/COLOR][/SIZE][SIZE=2] TCPCli
[/SIZE][SIZE=2][COLOR=#0000ff]Shared[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Sub[/COLOR][/SIZE][SIZE=2] Main()
[/SIZE][SIZE=2][COLOR=#0000ff]Dim[/COLOR][/SIZE][SIZE=2] tcpClient [/SIZE][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]New[/COLOR][/SIZE][SIZE=2] System.Net.Sockets.TcpClient
tcpClient.Connect("127.0.0.1", 8000)
[/SIZE][SIZE=2][COLOR=#0000ff]Dim[/COLOR][/SIZE][SIZE=2] networkStream [/SIZE][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][SIZE=2] NetworkStream = tcpClient.GetStream()
[/SIZE][SIZE=2][COLOR=#0000ff]If[/COLOR][/SIZE][SIZE=2] networkStream.CanWrite [/SIZE][SIZE=2][COLOR=#0000ff]And[/COLOR][/SIZE][SIZE=2] networkStream.CanRead [/SIZE][SIZE=2][COLOR=#0000ff]Then
[/COLOR][/SIZE][SIZE=2][COLOR=#008000]' Do a simple write.
[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Dim[/COLOR][/SIZE][SIZE=2] sendBytes [/SIZE][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][SIZE=2] [Byte]() = Encoding.ASCII.GetBytes("Is anybody there")
networkStream.Write(sendBytes, 0, sendBytes.Length)
[/SIZE][SIZE=2][COLOR=#008000]' Read the NetworkStream into a byte buffer.
[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Dim[/COLOR][/SIZE][SIZE=2] bytes(tcpClient.ReceiveBufferSize) [/SIZE][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Byte
[/COLOR][/SIZE][SIZE=2]networkStream.Read(bytes, 0, [/SIZE][SIZE=2][COLOR=#0000ff]CInt[/COLOR][/SIZE][SIZE=2](tcpClient.ReceiveBufferSize))
[/SIZE][SIZE=2][COLOR=#008000]' Output the data received from the host to the console.
[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Dim[/COLOR][/SIZE][SIZE=2] returndata [/SIZE][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]String[/COLOR][/SIZE][SIZE=2] = Encoding.ASCII.GetString(bytes)
Console.WriteLine(("Host returned: " + returndata))
[/SIZE][SIZE=2][COLOR=#0000ff]Else
[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]If[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Not[/COLOR][/SIZE][SIZE=2] networkStream.CanRead [/SIZE][SIZE=2][COLOR=#0000ff]Then
[/COLOR][/SIZE][SIZE=2]Console.WriteLine("cannot not write data to this stream")
tcpClient.Close()
[/SIZE][SIZE=2][COLOR=#0000ff]Else
[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]If[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Not[/COLOR][/SIZE][SIZE=2] networkStream.CanWrite [/SIZE][SIZE=2][COLOR=#0000ff]Then
[/COLOR][/SIZE][SIZE=2]Console.WriteLine("cannot read data from this stream")
tcpClient.Close()
[/SIZE][SIZE=2][COLOR=#0000ff]End[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]If
[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]End[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]If
[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]End[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]If
[/COLOR][/SIZE][SIZE=2][COLOR=#008000]' pause so user can view the console output
[/COLOR][/SIZE][SIZE=2]Console.ReadLine()
[/SIZE][SIZE=2][COLOR=#0000ff]End[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Sub
[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]End[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Class
[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Public[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Sub[/COLOR][/SIZE][SIZE=2] Button1_Click([/SIZE][SIZE=2][COLOR=#0000ff]ByVal[/COLOR][/SIZE][SIZE=2] sender [/SIZE][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][SIZE=2] System.Object, [/SIZE][SIZE=2][COLOR=#0000ff]ByVal[/COLOR][/SIZE][SIZE=2] e [/SIZE][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][SIZE=2] System.EventArgs) [/SIZE][SIZE=2][COLOR=#0000ff]Handles[/COLOR][/SIZE][SIZE=2] Button1.Click
[/SIZE][SIZE=2][COLOR=#0000ff]Dim[/COLOR][/SIZE][SIZE=2] distance [/SIZE][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Integer
[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Dim[/COLOR][/SIZE][SIZE=2] signal = [/SIZE][SIZE=2][COLOR=#0000ff]String[/COLOR][/SIZE][SIZE=2].Empty
distance = Val(TxtDistance.Text)
lblwimax.Text = "This distance is " & distance & "miles. Will there be a sigal strength? " & signal
[/SIZE][SIZE=2][COLOR=#0000ff]End[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Sub
End[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Class[/COLOR][/SIZE]

the server program below is:

[SIZE=2][COLOR=#0000ff][SIZE=2][COLOR=#0000ff]Class[/COLOR][/SIZE][SIZE=2] TCPSrv
[/SIZE][SIZE=2][COLOR=#0000ff]Shared[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Sub[/COLOR][/SIZE][SIZE=2] Main()
[/SIZE][SIZE=2][COLOR=#008000]' Must listen on correct port- must be same as port client wants to connect on.
[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Dim[/COLOR][/SIZE][SIZE=2] TCPL [/SIZE][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][SIZE=2] TcpListener
TCPL = [/SIZE][SIZE=2][COLOR=#0000ff]New[/COLOR][/SIZE][SIZE=2] TcpListener(System.Net.IPAddress.Any, 23)
TCPL.Start()
Console.WriteLine("Waiting for connection...")
[/SIZE][SIZE=2][COLOR=#0000ff]Try
[/COLOR][/SIZE][SIZE=2][COLOR=#008000]'Accept the pending client connection and return 'a TcpClient initialized for communication. 
[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Dim[/COLOR][/SIZE][SIZE=2] tcpClient [/SIZE][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][SIZE=2] TcpClient = TCPL.AcceptTcpClient()
Console.WriteLine("Connection accepted.")
[/SIZE][SIZE=2][COLOR=#008000]' Get the stream
[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Dim[/COLOR][/SIZE][SIZE=2] networkStream [/SIZE][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][SIZE=2] NetworkStream = tcpClient.GetStream()
[/SIZE][SIZE=2][COLOR=#008000]' Read the stream into a byte array
[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Dim[/COLOR][/SIZE][SIZE=2] bytes(tcpClient.ReceiveBufferSize) [/SIZE][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Byte
[/COLOR][/SIZE][SIZE=2]networkStream.Read(bytes, 0, [/SIZE][SIZE=2][COLOR=#0000ff]CInt[/COLOR][/SIZE][SIZE=2](tcpClient.ReceiveBufferSize))
[/SIZE][SIZE=2][COLOR=#008000]' Return the data received from the client to the console.
[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Dim[/COLOR][/SIZE][SIZE=2] clientdata [/SIZE][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]String[/COLOR][/SIZE][SIZE=2] = Encoding.ASCII.GetString(bytes)
Console.WriteLine(("Client sent: " + clientdata))
[/SIZE][SIZE=2][COLOR=#0000ff]Dim[/COLOR][/SIZE][SIZE=2] responseString [/SIZE][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]String[/COLOR][/SIZE][SIZE=2] = "Connected to server."
[/SIZE][SIZE=2][COLOR=#0000ff]Dim[/COLOR][/SIZE][SIZE=2] sendBytes [/SIZE][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][SIZE=2] [Byte]() = Encoding.ASCII.GetBytes(responseString)
networkStream.Write(sendBytes, 0, sendBytes.Length)
Console.WriteLine(("Message Sent /> : " + responseString))
[/SIZE][SIZE=2][COLOR=#008000]'Any communication with the remote client using the TcpClient can go here.
[/COLOR][/SIZE][SIZE=2][COLOR=#008000]'Close TcpListener and TcpClient.
[/COLOR][/SIZE][SIZE=2]tcpClient.Close()
TCPL.Stop()
Console.WriteLine("exit")
Console.ReadLine()
[/SIZE][SIZE=2][COLOR=#0000ff]Catch[/COLOR][/SIZE][SIZE=2] e [/SIZE][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][SIZE=2] Exception
Console.WriteLine(e.ToString())
Console.ReadLine()
[/SIZE][SIZE=2][COLOR=#0000ff]End[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Try
[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]End[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Sub
[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]End[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Class
[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Class[/COLOR][/SIZE][SIZE=2] signal
[/SIZE][SIZE=2][COLOR=#0000ff]Shared[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Sub[/COLOR][/SIZE][SIZE=2] main()
[/SIZE][SIZE=2][COLOR=#0000ff]Dim[/COLOR][/SIZE][SIZE=2] distance [/SIZE][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Integer
[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Dim[/COLOR][/SIZE][SIZE=2] signal [/SIZE][SIZE=2][COLOR=#0000ff]As[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]String
[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]If[/COLOR][/SIZE][SIZE=2] distance <= 31 [/SIZE][SIZE=2][COLOR=#0000ff]then
[/COLOR][/SIZE][SIZE=2]signal = "Yes"
[/SIZE][SIZE=2][COLOR=#0000ff]Else[/COLOR][/SIZE][SIZE=2] : signal = "No"
[/SIZE][SIZE=2][COLOR=#0000ff]End[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]If
[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]End[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Sub
End[/COLOR][/SIZE][SIZE=2][COLOR=#0000ff]Class[/COLOR][/SIZE]
 
[/COLOR][/SIZE]

ok, the idea is that the distance is entered in a box on the form, the client program then passes the input to the server(2nd program - on another pc) which then returns a yes or no - the signal variable back to the client program which is output to the screen in a message.

What have i missed to get the responses I need back and forward between the two programs?

One I have got this sorted I can then write it up.

Thank you for your help it has been much appreciated.

Regards.

 

[JohnH]

Client and server need to communicate on same port, you have set server to listen on port 23 and you try to connect with client on port 8000.

I edited your post. Added code boxes for better readability. Removed all the Windows Designer Generated code that was and usually is irrelevant to the question. The post initially looked like an endless list of code lines and not two different applications plus problem descriptions. I changed the title to something more descriptive, a title like "I am a student" has nothing to do with the question you asked. I moved the post from VB.Net General forum to a more appropriate forum Net/sockets, a place where you also can find more help in existing posts and stand a much better chance of finding someone with knowledge to answer in the topic you ask about. So it seems you missed a lot.