[Tutorial][VB.Net] Asynchronized Server/Client Demo(using sockets)

Code:

Imports System.Net, System.Net.Sockets

Public Class frmServer

    Dim server As Socket

    Dim client As Socket

    Dim bytes As Byte() = New Byte(1023) {}

    Private Sub frmServer_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        server = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)

        Dim xEndpoint As IPEndPoint = New IPEndPoint(IPAddress.Any, 6969)

        server.Bind(xEndpoint)

        server.Listen(2)

        server.BeginAccept(New AsyncCallback(AddressOf OnAccept), vbNull)

    End Sub

    Private Sub OnAccept(ByVal ar As IAsyncResult)

        client = server.EndAccept(ar)

        client.BeginReceive(bytes, 0, bytes.Length, SocketFlags.None, New AsyncCallback(AddressOf OnRecieve), client)

    End Sub

    Private Sub OnRecieve(ByVal ar As IAsyncResult)

        client = ar.AsyncState

        client.EndReceive(ar)

        client.BeginReceive(bytes, 0, bytes.Length, SocketFlags.None, New AsyncCallback(AddressOf OnRecieve), client)

        Dim message As String = System.Text.ASCIIEncoding.ASCII.GetString(bytes)

        MessageBox.Show(message)

    End Sub

End Class

Code:

Imports System.Net, System.Net.Sockets

Imports System.Text.ASCIIEncoding

Public Class frmClient

    Dim client As Socket

    Dim host As String = "127.0.0.1"

    Dim port As Integer = "6969"

    Private Sub btnConnect_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnConnect.Click

        client = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)

        Dim IP As IPAddress = IPAddress.Parse(host)

        Dim xIpEndPoint As IPEndPoint = New IPEndPoint(IP, port)

        client.BeginConnect(xIpEndPoint, New AsyncCallback(AddressOf OnConnect), Nothing)

        btnConnect.Enabled = False

    End Sub

    Private Sub btnSend_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSend.Click

        Dim bytes As Byte() = ASCII.GetBytes(txtMessage.Text)

        client.BeginSend(bytes, 0, bytes.Length, SocketFlags.None, New AsyncCallback(AddressOf OnSend), client)

    End Sub

    Private Sub OnConnect(ByVal ar As IAsyncResult)

        client.EndConnect(ar)

        MessageBox.Show("Connected")

    End Sub

    Private Sub OnSend(ByVal ar As IAsyncResult)

        client.EndSend(ar)

    End Sub



End Class