[RESOLVED] TCP Sockets Problem

[keystone_paul]

I'b dabbling with a client/server application which uses TCP sockets to communicate between a server and multiple clients.

I'm working from various examples on other messageboards and the MSDN and have hit a problem.

I'm working on a login function - the client sends a message comprised of a token "<L>" and the username and password (not worrying about encryption at the moment as its just a proof of concept)

When the server receives a message with the <L> token it parses the username and password, checks them against its list of valid users and passwords and returns either <F> if it fails or <R> plus a number if it succeeds.

The problem I've got is that the server receives the message OK, checks the username and password OK, formulates the string response OK, and sends the message back.

When the client receives the message it appears to be getting a blank message, but of the correct length! By that I mean I check on the server and it is sending back a 14 character message, and the client is receiving a 14 character message but it is empty.

The code on the server for sending is :

     Public Sub SendMessage(ByVal Message As String)

        Dim _Client As New TcpClient(_ServerIPAdress, _ServerPort)

        Message = _ServerIPAdress & "::" & Message

        Dim data As [Byte]() = System.Text.Encoding.ASCII.GetBytes(Message)
        Dim stream As NetworkStream = _Client.GetStream()

        ' Send the message to the connected TcpServer. 
        stream.Write(data, 0, data.Length)

        stream.Close()
        _Client.Close()
        _Client = Nothing

    End Sub

And the receiving code is

    Private Sub OnRead(ByVal AR As IAsyncResult)

        Dim DataSize As Integer = _InboundClient.GetStream.EndRead(AR)
        Dim Buffer(DataSize) As Byte
        Dim Message As String

        Message = Encoding.ASCII.GetString(Buffer, 0, DataSize)

        If Message <> "" Then Stop

        _InboundClient.GetStream.BeginRead(Buffer, 0, DataSize, AddressOf OnRead, Nothing)

    End Sub

When I look at the elements of Buffer they all seem to hold 0.

I'm sure its something really obvious but I'm just going blind looking at the same bit of code! Obviously the message sending is OK but there's something wrong with the way i'm retrieving it.

Any ideas?

[keystone_paul]

Resolved it - had a variable scoping problem - Buffer needed to be a module-level variable as it was being filled in a different procedure