Threaded Async programming TCP Client Server

talk about a new calculus of programming, learning to write in Async threaded TCP is interesting.

 

just the Invoke command alone, is interesting. feels like learning calculus to an ole programmer like me, but I get it. parallel processing, multi-threaded, no longer linear tasking and Application.DoEvents() just does not do the trick anymore.. ha!! for some of my older programmers who still just do basic stuff and the thought of multi-tasking multi-threaded parallel tasking, aside from my Unix programmers who were doing tasking back in 1960s and 70s.

 

if they still exist. check out the two examples found at the drop box of hc-kr.com , client, server

 there are a few more examples for tcp client server async invoke programming at Microsoft similar to these that are just as valuable.

 

 

 

 

© hc-kr.com below

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 server

=====================

 Imports System.Net
Imports System.IO
Imports System.Net.Sockets
Public Class Form1
    Dim Listning As TcpListener
    Dim Allclient As TcpClient
    Dim clientList As New List(Of ClassforClient)
    Dim pReader As StreamReader
    Dim pClient As ClassforClient
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Listning = New TcpListener(IPAddress.Any, 3818)
        Listning.Start()
        UpdateList("Server Starting", False)
        Listning.BeginAcceptTcpClient(New AsyncCallback(AddressOf AcceptClient), Listning)
    End Sub
    ' create a delegate
    Delegate Sub _cUpdate(ByVal str As String, ByVal relay As Boolean)
    Sub UpdateList(ByVal str As String, ByVal relay As Boolean)
        On Error Resume Next
        If InvokeRequired Then
            Invoke(New _cUpdate(AddressOf UpdateList), str, relay)
        Else
            TextBox1.AppendText(str & vbNewLine)
            ' if relay we will send a string
            If relay Then send(str)
        End If
    End Sub
    Sub send(ByVal str As String)
        For x As Integer = 0 To clientList.Count - 1
            Try
                clientList(x).Send(str)
            Catch ex As Exception
                clientList.RemoveAt(x)
            End Try
        Next
    End Sub
    Sub AcceptClient(ByVal ar As IAsyncResult)
        pClient = New ClassforClient(Listning.EndAcceptTcpClient(ar))
        AddHandler(pClient.getMessage), AddressOf MessageReceived
        AddHandler(pClient.clientLogout), AddressOf ClientExited
        clientList.Add(pClient)
        UpdateList("New Client Joined!", True)
        Listning.BeginAcceptTcpClient(New AsyncCallback(AddressOf AcceptClient), Listning)
    End Sub
    Sub MessageReceived(ByVal str As String)
        UpdateList(str, True)
    End Sub
    Sub ClientExited(ByVal client As ClassforClient)
        clientList.Remove(client)
        UpdateList("Client Exited!", True)
    End Sub
    Private Sub TextBox2_KeyDown(sender As Object, e As KeyEventArgs) Handles TextBox2.KeyDown
        If e.KeyCode = Keys.Enter Then
            e.SuppressKeyPress = True
            UpdateList("Server says : " & TextBox2.Text, True)
            TextBox2.Clear()
        End If
    End Sub
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        UpdateList("Server says : " & TextBox2.Text, True)
        TextBox2.Clear()
    End Sub
End Class

=====================

 client

=====================

 Imports System.Net
Imports System.IO
Imports System.Net.Sockets
Public Class Form1
    Dim client As TcpClient
    Dim sWriter As StreamWriter
    Dim NIckFrefix As Integer = New Random().Next(1111, 9999)
    Sub xLoad() Handles Me.Load
        Me.Text &= " " & NIckFrefix
    End Sub
    Delegate Sub _xUpdate(ByVal str As String)
    Sub xUpdate(ByVal str As String)
        If InvokeRequired Then
            Invoke(New _xUpdate(AddressOf xUpdate), str)
        Else
            TextBox3.AppendText(str & vbNewLine)
        End If
    End Sub

    Sub read(ByVal ar As IAsyncResult)
        Try
            xUpdate(New StreamReader(client.GetStream).ReadLine)
            client.GetStream.BeginRead(New Byte() {0}, 0, 0, AddressOf read, Nothing)

        Catch ex As Exception
            xUpdate("You have disconnecting from server")
            Exit Sub
        End Try
    End Sub
    Private Sub send(ByVal str As String)
        Try
            sWriter = New StreamWriter(client.GetStream)
            sWriter.WriteLine(str)
            sWriter.Flush()
        Catch ex As Exception
            xUpdate("You're not server")
        End Try
    End Sub
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        If Button1.Text = "Connect" Then
            Try
                client = New TcpClient(TextBox1.Text, CInt(TextBox2.Text))
                client.GetStream.BeginRead(New Byte() {0}, 0, 0, New AsyncCallback(AddressOf read), Nothing)
                Button1.Text = "Disconnect"
            Catch ex As Exception
                xUpdate("Can't connect to the server!")
            End Try
        Else
            client.Client.Close()
            client = Nothing
            Button1.Text = "Connect"
        End If
    End Sub
    Private Sub TextBox4_KeyDown(sender As Object, e As KeyEventArgs) Handles TextBox4.KeyDown
        If e.KeyCode = Keys.Enter Then
            e.SuppressKeyPress = True
            send(NIckFrefix & " says : " & TextBox4.Text)
            TextBox4.Clear()
        End If
    End Sub
    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        send(NIckFrefix & " says : " & TextBox4.Text)
        TextBox4.Clear()
    End Sub
End Class

 

=====================

 end

 

more to come...