Simultaneously receive message from clients using sockets (with Async) - vb.net

Question

i have a CyberCafe Software Program with a code that sends a message by the client(socket) and received by the server(also a socket) using Network Stream. (i'm somewhat new about sockets and network stream)
Server Side:
'receive msg from client
Private Sub OnRecieve(ByVal ar As IAsyncResult)
Try
Dim ns As NetworkStream = CType(ar.AsyncState, NetworkStream)
ns.BeginRead(byteData, 0, byteData.Length, New AsyncCallback(AddressOf OnRecieve), ns)
Dim bytesRec As Byte() = byteData
Dim message As String = System.Text.ASCIIEncoding.ASCII.GetString(bytesRec)
Invoke(New _Read(AddressOf Read), message)
ns.Flush()
ns.Close()
Catch ex As Exception
'check for Disconnection or Force Disconnection
Invoke(New _dc(AddressOf dc))
End Try
End Sub
Client Side:
'send msg to server
Private Sub Send(ByVal msg As String, ByVal client As Socket)
Try
Dim sendBytes As Byte() = System.Text.ASCIIEncoding.ASCII.GetBytes(msg)
NetStream = New NetworkStream(client)
NetStream.BeginWrite(sendBytes, 0, sendBytes.Length, New AsyncCallback(AddressOf OnSend), NetStream)
Catch ex As Exception
If Not clientSocket.Connected Then 'if connection was forcibly disconnected
'reconnecting to the server
Invoke(New _status(AddressOf status), clientSocket)
Connect()
End If
End Try
End Sub
The scenario is, there are 2 clients waiting to connect to the server(the other one is a Virtual Machine), and when i finally run the server, simultaneous connection had no problems, but receiving a message simultaneously didn't worked out. Sometimes it received one message only. Sometimes the message is wrong. Maybe a deadlock.
So, how can i implement this kind of situation? i asked Brother Google :P and he told me about AsyncTask, but i dunno how to do it :(
Any help would be obliged ^_^ Apologies for any bad english.

Answer 1

Update:
Sorry for my incomplete question.
I've added the EndRead/EndWrite method, but i'm not sure if i used the EndRead method right... I just inserted the EndRead before the BeginRead, but it still works though.
Thank you for the help Visual Vincent ^_^.
Also, my sockets are stored in the ListView as tag after they connect. And their IPAddress and HostName are stored in the database (MSAccess). And i don't have any TCP used in this code. Just Sockets and NetworkStreams. IDK if that is ok, but it works.
Server Side(Full):
Imports System.Net, System.Net.Sockets
Imports System.Data.OleDb
Public Class Server
Dim serverSocket As Socket
Dim clientSocket As Socket
Dim netstream As NetworkStream
Dim byteData(1023) As Byte
Dim ipEndPoint As IPEndPoint
Dim myList As New List(Of String)
Dim myList2 As New List(Of String)
Dim txt As String
'listening to clients from port 8800
Private Sub frmServer_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Invoke(New _AddExistingClient(AddressOf AddExistingClient))
Listen()
End Sub
Delegate Sub _AddExistingClient()
Private Sub AddExistingClient()
Try
If conn.State = ConnectionState.Open Then conn.Close()
conn.Open()
query = "select * from Clients_tbl"
comm = New OleDbCommand(query, conn)
reader = comm.ExecuteReader
While reader.Read
Dim lvi As New ListViewItem(reader("HostName").ToString)
lvi.Text = reader("HostName")
lvi.SubItems.Add("P00.00") 'price 1
lvi.SubItems.Add("00:00:00") 'time 2
lvi.ImageKey = "Grey.ico"
lsvClients.Items.Add(lvi)
End While
lsvClients.Sort()
conn.Close()
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Private Sub Listen()
Try
serverSocket = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
ipEndPoint = New IPEndPoint(IPAddress.Any, 8800)
serverSocket.Bind(ipEndPoint)
serverSocket.Listen(1)
serverSocket.BeginAccept(New AsyncCallback(AddressOf OnAccept), Nothing)
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Private Sub OnAccept(ByVal ar As IAsyncResult)
Try
clientSocket = serverSocket.EndAccept(ar)
serverSocket.BeginAccept(New AsyncCallback(AddressOf OnAccept), Nothing)
CheckIfExist(clientSocket)
netstream = New NetworkStream(clientSocket)
netstream.BeginRead(byteData, 0, byteData.Length, New AsyncCallback(AddressOf OnRecieve), netstream)
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Delegate Sub _CheckIfExist(ByVal client As Socket)
Private Sub CheckIfExist(ByVal client As Socket)
Try
If InvokeRequired Then
Invoke(New _CheckIfExist(AddressOf CheckIfExist), client)
Exit Sub
End If
Dim RemoteIP As String = IPAddress.Parse(CType(client.RemoteEndPoint, IPEndPoint).Address.ToString).ToString
Dim host As String = Dns.GetHostEntry(RemoteIP).HostName.ToString
If conn.State = ConnectionState.Open Then conn.Close()
conn.Open()
query = "select * from Clients_tbl where HostName = '" + host + "'"
comm = New OleDbCommand(query, conn)
reader = comm.ExecuteReader
While reader.Read
If reader("IPAddress").ToString <> RemoteIP Then 'if socket do exist in the database but IPAddress was changed
ChangeIP(RemoteIP, host)
End If
count += 1
End While
If count = 0 Then 'if socket do not exist in the database
Add2DB(RemoteIP, host)
AddNewClient(client)
ElseIf count = 1 Then 'if socket do exist in the database and in the listview
For Each item As ListViewItem In lsvClients.Items
If item.Text = host Then
item.Tag = client
item.ImageKey = "Red.ico"
End If
Next
ElseIf count > 1 Then
MsgBox("Duplicate found")
End If
count = 0
conn.Close()
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Delegate Sub _ChangeIP(ByVal RemoteIP As String, ByVal host As String)
Private Sub ChangeIP(ByVal RemoteIP As String, ByVal host As String) 'connection is still opened
Try
If InvokeRequired Then
Invoke(New _ChangeIP(AddressOf ChangeIP), RemoteIP, host)
Exit Sub
End If
query = "update Clients_tbl set IPAddress = '" + RemoteIP + "' where HostName = '" + host + "'"
comm = New OleDbCommand(query, conn)
reader = comm.ExecuteReader
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Delegate Sub _Add2DB(ByVal RemoteIP As String, ByVal host As String)
Private Sub Add2DB(ByVal RemoteIP As String, ByVal host As String) 'connection is still opened
Try
If InvokeRequired Then
Invoke(New _Add2DB(AddressOf Add2DB), RemoteIP, host)
Exit Sub
End If
query = "insert into Clients_tbl values('" + RemoteIP + "', '" + host + "')"
comm = New OleDbCommand(query, conn)
reader = comm.ExecuteReader
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
'add client to ListView
Delegate Sub _AddNewClient(ByVal client As Socket)
Private Sub AddNewClient(ByVal client As Socket)
Try
If InvokeRequired Then
Invoke(New _AddNewClient(AddressOf AddNewClient), client)
Exit Sub
End If
Dim lvi As New ListViewItem(client.LocalEndPoint.ToString)
Dim RemoteIP As String = IPAddress.Parse(CType(client.RemoteEndPoint, IPEndPoint).Address.ToString).ToString
Dim host As String = Dns.GetHostEntry(RemoteIP).HostName.ToString
lvi.Text = host
lvi.Tag = client
lvi.SubItems.Add("P00.00") 'price 1
lvi.SubItems.Add("00:00:00") 'time 2
lvi.ImageKey = "Red.ico"
lsvClients.Items.Add(lvi)
lsvClients.Sort()
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
'Send msg to specific client
Private Sub Send(ByVal msg As String, ByVal client As Socket)
Try
netstream = New NetworkStream(client)
Dim sendBytes As Byte() = System.Text.ASCIIEncoding.ASCII.GetBytes(msg)
netstream.BeginWrite(sendBytes, 0, sendBytes.Length, New AsyncCallback(AddressOf OnSend), netstream)
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Private Sub OnSend(ByVal ar As IAsyncResult)
Try
Dim ns As NetworkStream = CType(ar.AsyncState, NetworkStream)
ns.EndWrite(ar)
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Delegate Sub _dc()
Private Sub dc()
For Each lvi As ListViewItem In lsvClients.Items
If Not lvi.Tag Is Nothing Then
Dim S As Socket = lvi.Tag
If Not S.Connected Then lvi.ImageKey = "Grey.ico"
End If
Next
End Sub
'receive msg from client
Private Sub OnRecieve(ByVal ar As IAsyncResult)
Try
Dim ns As NetworkStream = CType(ar.AsyncState, NetworkStream)
ns.EndRead(ar)
ns.BeginRead(byteData, 0, byteData.Length, New AsyncCallback(AddressOf OnRecieve), ns)
Dim bytesRec As Byte() = byteData
Dim message As String = System.Text.ASCIIEncoding.ASCII.GetString(bytesRec)
Invoke(New _Read(AddressOf Read), message)
ns.Flush()
ns.Close()
Catch ex As Exception
'check for Disconnection or Force Disconnection
Invoke(New _dc(AddressOf dc))
End Try
End Sub
Delegate Sub _Read(ByVal msg As String)
Private Sub Read(ByVal msg As String)
Try
myList2 = msg.Split("~").ToList
'mylist.Add("0") 'command number
'mylist.Add(host) 'host name of this client
'mylist.Add(lblState.Text)
'mylist.Add(lblTime.Tag.ToString)
Select Case Integer.Parse(myList2(0))
Case 0
For Each lvi As ListViewItem In lsvClients.Items
If lvi.Text = myList2(1) Then
If myList2(2) = "Timed" Then
lvi.ImageKey = "Green.ico"
ElseIf myList2(2) = "Open"
lvi.ImageKey = "Blue.ico"
End If
lvi.SubItems(2).Tag = Integer.Parse(myList2(3))
End If
Next
End Select
myList2.Clear()
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Private Sub Timer1_Tick(ByVal sender As Object, ByVal e As EventArgs) Handles Timer1.Tick
Invoke(New _Counter(AddressOf Counter))
End Sub
Delegate Sub _Counter()
Private Sub Counter()
Try
If lsvClients.Items.Count > 0 Then
For Each time As ListViewItem In lsvClients.Items
'//////////////
If time.ImageKey = "Green.ico" Then
time.SubItems(2).Tag -= 1
time.SubItems(2).Text = GetTime(time.SubItems(2).Tag)
If time.SubItems(2).Tag = 0 Then time.ImageKey = "Red.ico"
ElseIf time.ImageKey = "Blue.ico" Then
time.SubItems(2).Tag += 1
time.SubItems(2).Text = GetTime(time.SubItems(2).Tag)
End If
'//////////////
Next
End If
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Private Function GetTime(ByVal time As Integer) As String
Dim Hrs As Integer 'number of hours '
Dim Min As Integer 'number of Minutes '
Dim Sec As Integer 'number of Sec '
'Seconds'
Sec = time Mod 60
'Minutes'
Min = ((time - Sec) / 60) Mod 60
'Hours'
Hrs = ((time - (Sec + (Min * 60))) / 3600) Mod 60
Return Format(Hrs, "00") & ":" & Format(Min, "00") & ":" & Format(Sec, "00")
End Function
Private Sub btnStartTime_Click(sender As Object, e As EventArgs) Handles btnStartTime.Click
Try
If lsvClients.SelectedItems.Count <> 0 Then
myList.Add("0")
myList.Add("10") 'time
myList.Add("15") 'price
txt = String.Join("~", myList)
Send(txt, lsvClients.SelectedItems(0).Tag)
lsvClients.SelectedItems(0).SubItems(2).Tag = myList(1)
lsvClients.SelectedItems(0).ImageKey = "Green.ico"
myList.Clear()
Else
MsgBox("Select first")
End If
Catch ex As Exception
Dim client As Socket = lsvClients.SelectedItems(0).Tag
If Not client.Connected Then
MsgBox("Disconnected")
End If
End Try
End Sub
Private Sub btnOpenTime_Click(sender As Object, e As EventArgs) Handles btnOpenTime.Click
Try
If lsvClients.SelectedItems.Count <> 0 Then
myList.Add("2")
myList.Add("0") 'time
myList.Add("0") 'price
txt = String.Join("~", myList)
Send(txt, lsvClients.SelectedItems(0).Tag)
lsvClients.SelectedItems(0).SubItems(2).Tag = myList(1)
lsvClients.SelectedItems(0).ImageKey = "Blue.ico"
myList.Clear()
Else
MsgBox("Select first")
End If
Catch ex As Exception
Dim client As Socket = lsvClients.SelectedItems(0).Tag
If Not client.Connected Then
MsgBox("Disconnected")
End If
End Try
End Sub
Private Sub btnExtendTime_Click(sender As Object, e As EventArgs) Handles btnExtendTime.Click
Try
If lsvClients.SelectedItems.Count <> 0 Then
myList.Add("1")
myList.Add("10") 'time
myList.Add("15") 'price
txt = String.Join("~", myList)
Send(txt, lsvClients.SelectedItems(0).Tag)
lsvClients.SelectedItems(0).SubItems(2).Tag += myList(1)
lsvClients.SelectedItems(0).ImageKey = "Green.ico"
myList.Clear()
Else
MsgBox("Select first")
End If
Catch ex As Exception
Dim client As Socket = lsvClients.SelectedItems(0).Tag
If Not client.Connected Then
MsgBox("Disconnected")
End If
End Try
End Sub
Private Sub btnPauseTime_Click(sender As Object, e As EventArgs) Handles btnPauseTime.Click
Try
If lsvClients.SelectedItems.Count <> 0 Then
myList.Add("3")
myList.Add("00:00:00") 'time
myList.Add("0") 'price
txt = String.Join("~", myList)
Send(txt, lsvClients.SelectedItems(0).Tag)
If lsvClients.SelectedItems(0).ImageKey = "Green.ico" Then
lsvClients.SelectedItems(0).ImageKey = "Green2Yellow.ico"
ElseIf lsvClients.SelectedItems(0).ImageKey = "Blue.ico"
lsvClients.SelectedItems(0).ImageKey = "Blue2Yellow.ico"
End If
myList.Clear()
Else
MsgBox("Select first")
End If
Catch ex As Exception
Dim client As Socket = lsvClients.SelectedItems(0).Tag
If Not client.Connected Then
MsgBox("Disconnected")
End If
End Try
End Sub
Private Sub btnResumeTime_Click(sender As Object, e As EventArgs) Handles btnResumeTime.Click
Try
If lsvClients.SelectedItems.Count <> 0 Then
myList.Add("4")
myList.Add("00:00:00") 'time
myList.Add("0") 'price
txt = String.Join("~", myList)
Send(txt, lsvClients.SelectedItems(0).Tag)
If lsvClients.SelectedItems(0).ImageKey = "Green2Yellow.ico" Then
lsvClients.SelectedItems(0).ImageKey = "Green.ico"
ElseIf lsvClients.SelectedItems(0).ImageKey = "Blue2Yellow.ico"
lsvClients.SelectedItems(0).ImageKey = "Blue.ico"
End If
myList.Clear()
Else
MsgBox("Select first")
End If
Catch ex As Exception
Dim client As Socket = lsvClients.SelectedItems(0).Tag
If Not client.Connected Then
MsgBox("Disconnected")
End If
End Try
End Sub
End Class
Client Side(full):
Imports System.Net, System.Net.Sockets, System.IO
Public Class Client
Dim clientSocket As Socket
Dim NetStream As NetworkStream
Dim byteData(1023) As Byte
Dim ipEndpoint As IPEndPoint
Dim host As String = Dns.GetHostName
Dim ip As IPAddress = IPAddress.Parse("192.168.56.1") 'Dns.GetHostEntry(host).AddressList(0)
Dim AppPath As String = Application.StartupPath
Dim writer As StreamWriter
Dim reader As StreamReader
Dim mylist As New List(Of String)
Dim txt As String
'/////////////////////connecting to server at port 8800
Private Sub Client_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
Try
Invoke(New _readtext(AddressOf readtext))
Connect()
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Private Sub Connect()
Try
clientSocket = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
ipEndpoint = New IPEndPoint(ip, 8800)
clientSocket.BeginConnect(ipEndpoint, New AsyncCallback(AddressOf OnConnect), Nothing)
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Private Sub OnConnect(ByVal ar As IAsyncResult)
Try
Invoke(New _status(AddressOf status), clientSocket)
clientSocket.EndConnect(ar)
'Invoke(New _SendTimeState(AddressOf SendTimeState))
NetStream = New NetworkStream(clientSocket)
NetStream.BeginRead(byteData, 0, byteData.Length, New AsyncCallback(AddressOf Recieve), NetStream)
'Invoke(New _SendTimeState(AddressOf SendTimeState))
Catch ex As Exception
If Not clientSocket.Connected Then
Invoke(New _status(AddressOf status), clientSocket)
Connect()
End If
End Try
End Sub
Delegate Sub _SendTimeState()
Private Sub SendTimeState()
Try
mylist.Add("0") 'command number
mylist.Add(host) 'host name of this client
mylist.Add(lblState.Text)
mylist.Add(lblTime.Tag.ToString)
txt = String.Join("~", mylist)
Send(txt, clientSocket)
txt = ""
mylist.Clear()
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Delegate Sub _readtext()
Private Sub readtext()
Try
reader = New StreamReader(AppPath & "\time.txt")
Dim x As Integer = reader.ReadLine
reader.Close()
If x <> 0 Then
lblTime.Tag = x
reader = New StreamReader(AppPath & "\state.txt")
Dim state As String = reader.ReadLine
reader.Close()
lblState.Text = state
Timer1.Start()
End If
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Delegate Sub _writetext(ByVal file As String, ByVal txt As String)
Private Sub writetext(ByVal file As String, ByVal txt As String)
Try
If InvokeRequired Then
Invoke(New _writetext(AddressOf writetext), file, txt)
Exit Sub
End If
writer = New StreamWriter(AppPath & file, False)
writer.WriteLine(txt)
writer.Close()
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Delegate Sub _status(ByVal client As Socket)
Private Sub status(ByVal client As Socket)
lblConnection.Text = client.Connected.ToString
End Sub
'receive msg from server
Private Sub Recieve(ByVal ar As IAsyncResult)
Try
Dim ns As NetworkStream = CType(ar.AsyncState, NetworkStream)
ns.EndRead(ar)
ns.BeginRead(byteData, 0, byteData.Length, New AsyncCallback(AddressOf Recieve), ns)
Dim bytesRec As Byte() = byteData
Dim message As String = System.Text.ASCIIEncoding.ASCII.GetString(bytesRec)
Invoke(New _Read(AddressOf Read), message)
Catch ex As Exception
If Not clientSocket.Connected Then 'if connection was forcibly disconnected
'reconnecting to the server
Invoke(New _status(AddressOf status), clientSocket)
Connect()
End If
End Try
End Sub
Delegate Sub _Read(ByVal msg As String)
Private Sub Read(ByVal msg As String)
Try
mylist = msg.Split("~").ToList
'mylist(0) is command
'mylist(1) is time
'mylist(2) price
Select Case Integer.Parse(mylist(0))
Case 0 'timed
lblState.Text = "Timed"
lblTime.Tag = Integer.Parse(mylist(1))
lblTime.Text = GetTime(lblTime.Tag)
lblPrice.Text = Integer.Parse(lblPrice.Text) + Integer.Parse(mylist(2))
lblState.Tag = lblState.Text
writetext("\time.txt", lblTime.Tag.ToString)
writetext("\state.txt", "Timed")
Timer1.Start()
Case 1 'extend time
lblTime.Tag += Integer.Parse(mylist(1))
lblTime.Text = GetTime(lblTime.Tag)
lblPrice.Text = Integer.Parse(lblPrice.Text) + Integer.Parse(mylist(2))
If Not Timer1.Enabled Then Timer1.Start()
Case 2 'open time
lblState.Text = "Open"
lblTime.Tag = Integer.Parse(mylist(1))
lblTime.Text = GetTime(lblTime.Tag)
lblPrice.Text = mylist(2)
lblState.Tag = lblState.Text
writetext("\time.txt", lblTime.Tag.ToString)
writetext("\state.txt", "Open")
Timer1.Start()
Case 3 'pause time
lblState.Text = "Paused"
Timer1.Stop()
Case 4 'resume time
lblState.Text = lblState.Tag
Timer1.Start()
Case 5 'stop time
lblState.Text = "Stop"
writetext("\time.txt", "0")
writetext("\state.txt", "Stop")
Timer1.Stop()
Case 6 'shutdown
Case 7 'reset
Case 8 'send msg
End Select
mylist.Clear()
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
'send msg to server
Private Sub Send(ByVal msg As String, ByVal client As Socket)
Try
Dim sendBytes As Byte() = System.Text.ASCIIEncoding.ASCII.GetBytes(msg)
NetStream = New NetworkStream(client)
NetStream.BeginWrite(sendBytes, 0, sendBytes.Length, New AsyncCallback(AddressOf OnSend), NetStream)
Catch ex As Exception
If Not clientSocket.Connected Then 'if connection was forcibly disconnected
'reconnecting to the server
Invoke(New _status(AddressOf status), clientSocket)
Connect()
End If
End Try
End Sub
Private Sub OnSend(ByVal ar As IAsyncResult)
Try
Dim ns As NetworkStream = CType(ar.AsyncState, NetworkStream)
ns.EndWrite(ar)
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Private Sub Timer1_Tick(ByVal sender As Object, ByVal e As EventArgs) Handles Timer1.Tick
Try
Select Case lblState.Text
Case "Timed"
lblTime.Tag -= 1
lblTime.Text = GetTime(lblTime.Tag)
writetext("\time.txt", lblTime.Tag.ToString)
If lblTime.Tag = 0 Then Timer1.Stop()
Case "Open"
lblTime.Tag += 1
lblTime.Text = GetTime(lblTime.Tag)
writetext("\time.txt", lblTime.Tag.ToString)
End Select
Catch ex As Exception
If Not clientSocket.Connected Then 'if connection was forcibly disconnected
'reconnecting to the server
Invoke(New _status(AddressOf status), clientSocket)
Connect()
End If
MsgBox(ex.ToString)
End Try
End Sub
Private Function GetTime(ByVal time As Integer) As String
Dim Hrs As Integer 'number of hours '
Dim Min As Integer 'number of Minutes '
Dim Sec As Integer 'number of Sec '
'Seconds'
Sec = time Mod 60
'Minutes'
Min = ((time - Sec) / 60) Mod 60
'Hours'
Hrs = ((time - (Sec + (Min * 60))) / 3600) Mod 60
Return Format(Hrs, "00") & ":" & Format(Min, "00") & ":" & Format(Sec, "00")
End Function
End Class
OleDb Module:
Imports System.Data.OleDb
Module oledb
Dim AppPath As String = Application.StartupPath
Public conn As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + AppPath + "\ServerDatabase.mdb;User Id=Admin;Password=")
Public comm As OleDbCommand
Public reader As OleDbDataReader
Public query As String
Public count As Integer
End Module
(Can't add this post on my first post because it reached it's max capacity :P)

Answer 2

Here's the slightly changed Received function:
'receive msg from client
Private Sub Recieve(ByVal ar As IAsyncResult)
Try
Dim ns As NetworkStream = CType(ar.AsyncState, NetworkStream)
Dim message As String = ""
ByteSize = ns.EndRead(ar)
message = String.Concat(message, System.Text.ASCIIEncoding.ASCII.GetString(byteData, 0, ByteSize))
ns.BeginRead(byteData, 0, byteData.Length, New AsyncCallback(AddressOf Recieve), ns)
'if there are still data left in the network stream
While ns.DataAvailable
ns.BeginRead(byteData, 0, byteData.Length, New AsyncCallback(AddressOf Recieve), ns)
End While
Invoke(New _Read(AddressOf Read), message)
Catch ex As Exception
'check for Disconnection or Force Disconnection
Invoke(New _dc(AddressOf dc))
End Try
End Sub
I saw on the MS Documentation about NetworkStream.EndRead that the EndRead comes first before BeginRead. Maybe it is only applicable on Read.
NetworkStream.EndRead Method (IAsyncResult)
But the problem still persist :(