Two way client and server? - vb.net

Question

I created a one way client server communication so that the client can send messages to the server which just receives them. How can I modify the code so that both the server and the client can send and receive messages.
Client Code:
TCPControl.vb
Imports System.Net
Imports System.Net.Sockets
Imports System.IO
Public Class TCPControl
Public Client As TcpClient
Public DataStream As StreamWriter
Public Sub New(Host As String, Port As Integer)
' CLIENT
Client = New TcpClient(Host, Port)
DataStream = New StreamWriter(Client.GetStream)
End Sub
Public Sub Send(Data As String)
DataStream.Write(Data & vbCrLf)
DataStream.Flush()
End Sub
End Class
Form1.vb
Public Class Form1
Private Client As TCPControl
Private Sub cmdSend_Click(sender As System.Object, e As System.EventArgs) Handles cmdSend.Click
SendMessage()
txtMessage.Clear()
txtMessage.Focus()
End Sub
Private Sub cmdConnect_Click(sender As System.Object, e As System.EventArgs) Handles cmdConnect.Click
Client = New TCPControl("10.0.0.253", 64555)
If Client.Client.Connected Then cmdConnect.Text = "Connected"
End Sub
Private Sub Form1_FormClosing(sender As Object, e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
If Client.Client.Connected = True Then
Client.DataStream.Close()
Client.Client.Close()
End If
End Sub
Private Sub txtMessage_KeyDown(sender As Object, e As System.Windows.Forms.KeyEventArgs) Handles txtMessage.KeyDown
If e.KeyCode = Keys.Enter Then SendMessage()
End Sub
Private Sub SendMessage()
If Client.Client.Connected = True Then Client.Send(txtMessage.Text)
End Sub
End Class
Server Code:
TCPControl.vb
Imports System.IO
Imports System.Net
Imports System.Net.Sockets
Imports System.Threading
Public Class TCPControl
Public Event MessageReceived(sender As TCPControl, Data As String)
' SERVER CONFIG
Public ServerIP As IPAddress = IPAddress.Parse("10.0.0.253")
Public ServerPort As Integer = 64555
Public Server As TcpListener
Private CommThread As Thread
Public IsListening As Boolean = True
' CLIENTS
Private Client As TcpClient
Private ClientData As StreamReader
Public Sub New()
Server = New TcpListener(ServerIP, ServerPort)
Server.Start()
CommThread = New Thread(New ThreadStart(AddressOf Listening))
CommThread.Start()
End Sub
Private Sub Listening()
' CREATE LISTENER LOOP
Do Until IsListening = False
' ACCEPT INCOMING CONNECTIONS
If Server.Pending = True Then
Client = Server.AcceptTcpClient
ClientData = New StreamReader(Client.GetStream)
End If
' RAISE EVENT FOR INCOMING MESSAGES
Try
RaiseEvent MessageReceived(Me, ClientData.ReadLine)
Catch ex As Exception
End Try
' REDUCE CPU USAGE
'Thread.Sleep(100)
Loop
End Sub
End Class
Public Class Form1
Private Server As TCPControl
Private Sub Form1_FormClosing(sender As Object, e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
Server.IsListening = False
End Sub
TCPControl.vb
Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
Server = New TCPControl
txtChat.Text = ":: SERVER STARTED ::" & vbCrLf
AddHandler Server.MessageReceived, AddressOf OnLineReceived
End Sub
' ALLOW THREAD TO COMMUNICATE WITH FORM CONTROL
Private Delegate Sub UpdateTextDelegate(TB As TextBox, txt As String)
' UPDATE TEXTBOX
Private Sub UpdateText(TB As TextBox, txt As String)
If TB.InvokeRequired Then
TB.Invoke(New UpdateTextDelegate(AddressOf UpdateText), New Object() {TB, txt})
Else
If txt IsNot Nothing Then TB.AppendText(txt & vbCrLf)
End If
End Sub
' UPDATE TEXT WHEN DATA IS RECEIVED
Private Sub OnLineReceived(sender As TCPControl, Data As String)
UpdateText(txtChat, Data)
End Sub
End Class