Client/Server Application

[seen_4]

Hello,

Im new to .Net, I am wanting to create a Client and Server Application.
Client on a Hand Held Device and Server on a desktop computer.

I have some code I have already seen on the internet and modified. I am having some problems with this code.

First Question is just to make sure I am going about this right way?
Is using TCP connections the best way to do this?

Second question is I can get the client side to connect to the server, once there is a period of inactivity for around 5 - 10 mins the server crashes.

Is there anything I can do about this?




Server Code
-----------------------
Imports System.Threading

Module Module1

Public Sub Main()
Dim mySrv As sserver = New sserver(2001)
Dim tsrv As Thread = New Thread(AddressOf mySrv.startServer)
tsrv.Start()
End Sub

End Module




Imports System.IO
Imports System.Net
Imports System.Net.Sockets
Imports System.Threading
Imports System.Text
Imports Microsoft.VisualBasic.ControlChars

Public Class sserver
Private ASCII As Encoding = Encoding.ASCII
Private SListener As TcpListener
Private port As Integer
Private ReadOnly MAXCLIENT As Integer = 10
Private Shared ClientCount As Integer
Private ServerSocketForClientThread As Socket
Public Sub New(ByVal port As Integer)
MyBase.New()
Me.port = port
End Sub
Public Sub startServer()
Console.WriteLine("Trying to Start Server...")
SListener = New TcpListener(port)
'Start the Server
SListener.Start()
'Wait for Client to Connect
While (True)
Try
'Socket on which Server will Connect and Talk with Client
Console.WriteLine("Server Started waiting for Client Connection...")
Dim ServerSocketForClient As Socket = SListener.AcceptSocket
'If the Client Starts the Communication
'Create a NEW Thread for Each Client
'Increase the ClientCount
ClientCount += 1
If ClientCount <= MAXCLIENT Then
'Get the Socket on which
'Server and Client will Talk Within ClientThread
ServerSocketForClientThread = ServerSocketForClient
Console.WriteLine("Client Connection {0} from IP {1}...", ClientCount, ServerSocketForClient.RemoteEndPoint())
Dim ClientThread As Thread = New Thread(AddressOf CreateClientThread)
'Start Processing of client Thread
ClientThread.Start()
Else
'Make the Count Stable So the Operation of Existing Client is Performed
ClientCount -= 1
End If
Catch e As NotSupportedException
Console.WriteLine(e.ToString)
End Try
End While

End Sub

Private Sub CreateClientThread()
Dim ServerSocketForClient As Socket
ServerSocketForClient = ServerSocketForClientThread
'Wait for client to finish
While (True)
'Wait for Client Command on this socket

Dim byteArray(2048) As Byte
Try
Dim iBytes As Integer = ServerSocketForClient.Receive(byteArray, byteArray.Length, 0)
Dim MessageFromClient As String = Encoding.ASCII.GetString(byteArray)

If iBytes > 0 Then
SendMessageToClient(ServerSocketForClient, "From #" & ServerSocketForClient.RemoteEndPoint().ToString & "# " & MessageFromClient & CrLf)
Console.WriteLine("From #" & ServerSocketForClient.RemoteEndPoint().ToString & "# " & MessageFromClient)
Else
Exit While
End If
Catch e As NotSupportedException
Console.WriteLine(e.ToString)
End Try
End While
Console.WriteLine("Client Thread {0} From {1} Exited ", ClientCount, ServerSocketForClient.RemoteEndPoint())
'Decrement the Global Client Count
ClientCount -= 1
'Close the Socket
ServerSocketForClient.Close()
End Sub

Private Sub SendMessageToClient(ByVal SocketToUse As Socket, ByVal MessageToSend As String)
Dim ByteArray() As Byte = ASCII.Getbytes(MessageToSend.ToCharArray())
Try
SocketToUse.Send(ByteArray, ByteArray.Length, 0)
Catch e As SocketException

End Try
End Sub
End Class




Client Code
---------------------------
Imports System.Text
Imports System.Net.Sockets
'Imports VB = Microsoft.VisualBasic

Public Class Form1
Inherits System.Windows.Forms.Form
Friend WithEvents Button1 As System.Windows.Forms.Button
Friend WithEvents MainMenu1 As System.Windows.Forms.MainMenu
Friend WithEvents TextBox2 As System.Windows.Forms.TextBox
Friend WithEvents TextBox3 As System.Windows.Forms.TextBox
Private tClient As New sclient

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
tClient.sendmessagetoserver(TextBox2.Text)
If Not tClient.connected Then
Label1.Text = "disconnected"
Button1.Enabled = True
Button2.Enabled = False
Button3.Enabled = False
End If

End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

Try
tClient.connect(CInt(TextBox3.Text), TextBox1.Text)
Label1.Text = "Connected"
Button1.Enabled = False
Button2.Enabled = True
Button3.Enabled = True
Catch ex As Exception
MsgBox(ex.Message)
End Try

End Sub
Protected Overrides Sub Finalize()
MyBase.Finalize()
End Sub

Private Sub Form1_Closing(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing
Application.Exit()
End Sub

Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
Application.Exit()
End Sub

Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
Try
tClient.disconnect()
Label1.Text = "Disconnected"
Button1.Enabled = True
Button2.Enabled = False
Button3.Enabled = False
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
End Class

Thank you in advanced for any help.

[TokersBall_CDXX]

you should place your code snippets inside vbcode tags so it's easier to read the code.

perhaps you should look into Asynchronous Sockets
Asynchronous Server Socket Example