Module Module1
    Dim clientsList As New Hashtable
    Dim counter As Integer
    Sub Main()
 
        Try
            Dim serverSocket As New TcpListener(14531)
            Dim clientSocket As TcpClient
            Dim counter As Integer
 
            serverSocket.Start()
            msg("Started ....")
            counter = 0
 
            While (True)
                counter += 1
                clientSocket = serverSocket.AcceptTcpClient()
 
                Dim bytesFrom(10024) As Byte
                Dim dataFromClient As String
 
                Dim networkStream As NetworkStream = _
                clientSocket.GetStream()
                networkStream.Read(bytesFrom, 0, CInt( _
                  clientSocket.ReceiveBufferSize))
                dataFromClient = System.Text.Encoding.ASCII.GetString(bytesFrom)
                dataFromClient = _
                dataFromClient.Substring(0, dataFromClient.IndexOf("$"))
clientsList(dataFromClient) = clientSocket
broadcast(dataFromClient + "", dataFromClient, False)
msg(dataFromClient + "")
Dim client As New handleClinet
client.startClient(clientSocket, dataFromClient, clientsList)
End While
clientSocket.Close()
serverSocket.Stop()
msg("exit")
Console.ReadLine()
Catch ex As Exception
End Try
        End Sub
 
    Sub msg(ByVal mesg As String)
        Try
            mesg.Trim()
            Console.WriteLine(" : " + mesg)
        Catch ex As Exception
 
        End Try
 
    End Sub
    Private Sub broadcast(ByVal msg As String, _
    ByVal uName As String, ByVal flag As Boolean)
        Try
            Dim Item As DictionaryEntry
            For Each Item In clientsList
                Dim broadcastSocket As TcpClient
                broadcastSocket = CType(Item.Value, TcpClient)
                Dim broadcastStream As NetworkStream = _
                        broadcastSocket.GetStream()
                Dim broadcastBytes As [Byte]()
 
                If flag = True Then
                    broadcastBytes = Encoding.ASCII.GetBytes(uName + ": " + msg)
                Else
                    broadcastBytes = Encoding.ASCII.GetBytes(msg)
                End If
 
                broadcastStream.Write(broadcastBytes, 0, broadcastBytes.Length)
                broadcastStream.Flush()
            Next
        Catch ex As Exception
 
        End Try
 
    End Sub
 
    Public Class handleClinet
        Dim clientSocket As TcpClient
        Dim clNo As String
        Dim clientsList As Hashtable
 
        Public Sub startClient(ByVal inClientSocket As TcpClient, _
        ByVal clineNo As String, ByVal cList As Hashtable)
            Try
                Me.clientSocket = inClientSocket
                Me.clNo = clineNo
                Me.clientsList = cList
                Dim ctThread As Threading.Thread = New Threading.Thread( _
                  AddressOf doChat)
                ctThread.Start()
            Catch ex As Exception
 
            End Try
 
        End Sub
 
        Private Sub doChat()
            'Dim infiniteCounter As Integer
            Dim requestCount As Integer
            Dim bytesFrom(10024) As Byte
            Dim dataFromClient As String
            Dim sendBytes As [Byte]()
            Dim serverResponse As String
            Dim rCount As String
            requestCount = 0
 
            While (True)
                Try
                    requestCount = requestCount + 1
                    Dim networkStream As NetworkStream = _
                            clientSocket.GetStream()
                    networkStream.Read(bytesFrom, 0, CInt( _
                      clientSocket.ReceiveBufferSize))
                    dataFromClient = System.Text.Encoding.ASCII.GetString( _
                    bytesFrom)
                    dataFromClient = _
            dataFromClient.Substring(0, dataFromClient.IndexOf("$"))
                    msg("From client - " + clNo + " : " + dataFromClient)
                    rCount = Convert.ToString(requestCount)
 
                    broadcast(dataFromClient, clNo, True)
                Catch ex As Exception
                    MsgBox(ex.Message)
                End Try
 
            End While
        End Sub
 
    End Class
End Module