TCPListener

[iwdu15]

hi i have a working code for a tcpclient, but i cant seemt of figure out how
to use a tcplistener to connect with it. i just want to clck a button and
listen for a TCP conection and conect to a specific port, but any attempt i
try fails....any help would b awsome
--
-iwdu15

[Mike]

Re: TCPListener

Send your code to see what we can do

-----Original Message-----
From: iwdu15 [mailto:iwdu15@d iscussions.micr osoft.com]
Posted At: Wednesday, September 28, 2005 10:37 PM
Posted To: microsoft.publi c.dotnet.langua ges.vb
Conversation: TCPListener
Subject: TCPListener

hi i have a working code for a tcpclient, but i cant seemt of figure out
how
to use a tcplistener to connect with it. i just want to clck a button
and
listen for a TCP conection and conect to a specific port, but any
attempt i
try fails....any help would b awsome
--
-iwdu15

[iwdu15]

Re: TCPListener

ok, heres the code i tried for listening async:

#Region "Declaratio ns"

Dim homeip As Net.IPAddress
Dim ClientSocket As Net.Sockets.Soc ket
Dim ASCII As New System.Text.ASC IIEncoding

Dim ListenSocket As Net.Sockets.Soc ket

#End Region

#Region "Listen"

Private Sub btnlisten_Click (ByVal sender As System.Object, ByVal e As
System.EventArg s) Handles btnlisten.Click

Call Listen(homeip, Me.txtlistenpor t.Text)

End Sub

Private Sub Listen(ByVal IP As IPAddress, ByVal port As Integer)

Dim ep As New Net.IPEndPoint( IP, port)

ListenSocket = New Net.Sockets.Soc ket(AddressFami ly.InterNetwork ,
SocketType.Stre am, ProtocolType.Tc p)

ListenSocket.Be ginAccept(Addre ssOf ListenCallBack, Nothing)

End Sub

Private Sub ListenCallBack( ByVal ar As IAsyncResult)

Try
ListenSocket.En dAccept(ar)

'Begin Receiveing Data
Dim bytes(4095) As Byte
ClientSocket.Be ginReceive(byte s, 0, bytes.Length,
SocketFlags.Non e, AddressOf ListenReceiveCa llBack, bytes)

Catch ex As Exception
Me.rtbinfo.Text += vbNewLine & ex.Message & vbNewLine
End Try

End Sub

Private Sub ListenReceiveCa llBack(ByVal ar As IAsyncResult)

Dim bytes() As Byte = CType(ar.AsyncS tate, Byte())
Dim numbytes As Int32 = ListenSocket.En dReceive(ar)

If numbytes = 0 Then

ListenSocket.Sh utdown(SocketSh utdown.Both)
ListenSocket.Cl ose()

Else

Dim recv As String = ASCII.GetString (bytes, 0, numbytes)

'Clear the buffer
Array.Clear(byt es, 0, bytes.Length)

'Begin Receive Again
ClientSocket.Be ginReceive(byte s, 0, bytes.Length,
SocketFlags.Non e, AddressOf ListenReceiveCa llBack, bytes)

End If

End Sub

#End Region

thanks

-iwdu15

[Dragon]

Re: TCPListener

Hi,

A few comments about your code.

1. I don't see whether you assigned something to homeip.
2. I don't see if you bound ListenSocket to homeip, and put it into
listening state.
3. I don't see where you assigned something to ClientSocket before
receiving data from it.
4. In ListenReceiveCa llBack routine you call EndReceive from
ListenSocket, not ClientSocket.

So,

1.Assign something to homeip. For example, IPAddress.Any.
2. Insert ~ ListenSocket.Bi nd(ep) ~ and ~ ListenSocket.Li sten(0) ~ prior
to call to ListenSocket.Be ginAccept().
3. Change ~ ListenSocket.En dAccept(ar) ~ to ~ ClientSocket =
ListenSocket.En dAccept(ar) ~.
4. Change ~ ListenSocket.En dReceive ~ to ~ ClientSocket.En dReceive ~.

Hope this helps,
Roman

"iwdu15" <iwdu15@discuss ions.microsoft. com> ÓÏÏÂÝÉÌ/ÓÏÏÂÝÉÌÁ × ÎÏ×ÏÓÔÑÈ
ÓÌÅÄÕÀÝÅÅ: news:B41004B0-537F-4B1A-987F-E739692AA2F3@mi crosoft.com...[color=blue]
> ok, heres the code i tried for listening async:
>
> #Region "Declaratio ns"
>
> Dim homeip As Net.IPAddress
> Dim ClientSocket As Net.Sockets.Soc ket
> Dim ASCII As New System.Text.ASC IIEncoding
>
> Dim ListenSocket As Net.Sockets.Soc ket
>
> #End Region
>
> #Region "Listen"
>
> Private Sub btnlisten_Click (ByVal sender As System.Object, ByVal e[/color]
As[color=blue]
> System.EventArg s) Handles btnlisten.Click
>
> Call Listen(homeip, Me.txtlistenpor t.Text)
>
> End Sub
>
> Private Sub Listen(ByVal IP As IPAddress, ByVal port As Integer)
>
> Dim ep As New Net.IPEndPoint( IP, port)
>
> ListenSocket = New[/color]
Net.Sockets.Soc ket(AddressFami ly.InterNetwork ,[color=blue]
> SocketType.Stre am, ProtocolType.Tc p)
>
> ListenSocket.Be ginAccept(Addre ssOf ListenCallBack, Nothing)
>
> End Sub
>
> Private Sub ListenCallBack( ByVal ar As IAsyncResult)
>
> Try
> ListenSocket.En dAccept(ar)
>
> 'Begin Receiveing Data
> Dim bytes(4095) As Byte
> ClientSocket.Be ginReceive(byte s, 0, bytes.Length,
> SocketFlags.Non e, AddressOf ListenReceiveCa llBack, bytes)
>
> Catch ex As Exception
> Me.rtbinfo.Text += vbNewLine & ex.Message & vbNewLine
> End Try
>
> End Sub
>
> Private Sub ListenReceiveCa llBack(ByVal ar As IAsyncResult)
>
> Dim bytes() As Byte = CType(ar.AsyncS tate, Byte())
> Dim numbytes As Int32 = ListenSocket.En dReceive(ar)
>
> If numbytes = 0 Then
>
> ListenSocket.Sh utdown(SocketSh utdown.Both)
> ListenSocket.Cl ose()
>
> Else
>
> Dim recv As String = ASCII.GetString (bytes, 0, numbytes)
>
> 'Clear the buffer
> Array.Clear(byt es, 0, bytes.Length)
>
> 'Begin Receive Again
> ClientSocket.Be ginReceive(byte s, 0, bytes.Length,
> SocketFlags.Non e, AddressOf ListenReceiveCa llBack, bytes)
>
> End If
>
> End Sub
>
> #End Region
>
> thanks
>
> -iwdu15[/color]

[Supra]

Re: TCPListener

https://www.vbip.com

there is tutorial or use some googlle search

iwdu15 wrote:
[color=blue]
>hi i have a working code for a tcpclient, but i cant seemt of figure out how
>to use a tcplistener to connect with it. i just want to clck a button and
>listen for a TCP conection and conect to a specific port, but any attempt i
>try fails....any help would b awsome
>
>[/color]

[iwdu15]

Re: TCPListener

well that wasnt all my code, that was just relavant to the listening paert,
if u want i can show all my code, but homeip is used in the formload event to
get the IP address from the computer its running on, and clientsocket wis
used to send the connect request in my other code and the code endrecieve is
in there, il just list all my code here:

#Region "Declaratio ns"

Dim homeip As Net.IPAddress
Dim ClientSocket As Net.Sockets.Soc ket
Dim ASCII As New System.Text.ASC IIEncoding

Dim ListenSocket As Net.Sockets.Soc ket

#End Region

#Region "Connect"

Private Sub Form1_Load(ByVa l sender As System.Object, ByVal e As
System.EventArg s) Handles MyBase.Load

homeip =
Net.Dns.GetHost ByName(Net.Dns. GetHostName).Ad dressList.GetVa lue(0)

Me.Text = homeip.ToString

End Sub

Private Sub btnconnect_Clic k(ByVal sender As System.Object, ByVal e As
System.EventArg s) Handles btnconnect.Clic k

Dim addr As Net.IPAddress =
Net.Dns.Resolve (Me.txtIP.Text) .AddressList(0)

If Not addr Is Nothing Then
'Create IP endpoint
Dim EP As New Net.IPEndPoint( addr, CInt(Me.txtport .Text))

'create socket
ClientSocket = New
Net.Sockets.Soc ket(Net.Sockets .AddressFamily. InterNetwork,
Net.Sockets.Soc ketType.Stream, Net.Sockets.Pro tocolType.Tcp)

'Connect
ClientSocket.Be ginConnect(EP, AddressOf ConnectCallBack , Nothing)

End If

End Sub

Private Sub ConnectCallBack (ByVal ar As IAsyncResult)

Try
ClientSocket.En dConnect(ar)

Dim dlg As New NoParamsDelegat e(AddressOf ConnectedUI)

Me.Invoke(dlg)

'Begin Receiveing Data
Dim bytes(4095) As Byte
ClientSocket.Be ginReceive(byte s, 0, bytes.Length,
SocketFlags.Non e, AddressOf ReceiveCallBack , bytes)

Catch ex As Exception
Me.rtbinfo.Text += vbNewLine & ex.Message & vbNewLine
End Try

End Sub

Private Delegate Sub NoParamsDelegat e()

Private Sub ConnectedUI()

Me.rtbinfo.Text += vbNewLine & "Connected" & vbNewLine

Me.btnconnect.E nabled = False
Me.btnsend.Enab led = True
Me.rtbsend.Focu s()

End Sub

Private Sub DisconnectedUI( )

Me.rtbinfo.Text += vbNewLine & "Disconnect ed" & vbNewLine

Me.btnconnect.E nabled = True
Me.btnsend.Enab led = False
Me.btnconnect.F ocus()

End Sub

Private Sub ReceiveCallBack (ByVal ar As IAsyncResult)

Dim bytes() As Byte = CType(ar.AsyncS tate, Byte())
Dim numbytes As Int32 = ClientSocket.En dReceive(ar)

If numbytes = 0 Then
ClientSocket.Sh utdown(SocketSh utdown.Both)
ClientSocket.Cl ose()

Dim dlg As New NoParamsDelegat e(AddressOf DisconnectedUI)

Me.Invoke(dlg)
Else
Dim recv As String = ASCII.GetString (bytes, 0, numbytes)

'Clear the buffer
Array.Clear(byt es, 0, bytes.Length)

'Show in UI
Dim dlg As New OneStringDelega te(AddressOf DisplayReceived Data)
Dim args() As Object = {recv}

Me.Invoke(dlg, args)

'Begin Receive Again
ClientSocket.Be ginReceive(byte s, 0, bytes.Length,
SocketFlags.Non e, AddressOf ReceiveCallBack , bytes)

End If

End Sub

Private Sub DisplayReceived Data(ByVal data As String)

With Me.rtbsend
.SelectionStart = .Text.Length
.SelectedText = data

End With

End Sub

Private Delegate Sub OneStringDelega te(ByVal data As String)

Private Sub btnsend_Click(B yVal sender As System.Object, ByVal e As
System.EventArg s) Handles btnsend.Click

Dim bytes() As Byte = ASCII.GetBytes( Me.txtsend.Text )
ClientSocket.Se nd(bytes)

End Sub

#End Region

#Region "Listen"

Private Sub btnlisten_Click (ByVal sender As System.Object, ByVal e As
System.EventArg s) Handles btnlisten.Click

Call Listen(homeip, Me.txtlistenpor t.Text)

End Sub

Private Sub Listen(ByVal IP As IPAddress, ByVal port As Integer)

Dim ep As New Net.IPEndPoint( IP, port)

ListenSocket = New Net.Sockets.Soc ket(AddressFami ly.InterNetwork ,
SocketType.Stre am, ProtocolType.Tc p)

ListenSocket.Be ginAccept(Addre ssOf ListenCallBack, Nothing)

End Sub

Private Sub ListenCallBack( ByVal ar As IAsyncResult)

Try
ListenSocket.En dAccept(ar)

'Begin Receiveing Data
Dim bytes(4095) As Byte
ClientSocket.Be ginReceive(byte s, 0, bytes.Length,
SocketFlags.Non e, AddressOf ListenReceiveCa llBack, bytes)

Catch ex As Exception
Me.rtbinfo.Text += vbNewLine & ex.Message & vbNewLine
End Try

End Sub

Private Sub ListenReceiveCa llBack(ByVal ar As IAsyncResult)

Dim bytes() As Byte = CType(ar.AsyncS tate, Byte())
Dim numbytes As Int32 = ListenSocket.En dReceive(ar)

If numbytes = 0 Then

ListenSocket.Sh utdown(SocketSh utdown.Both)
ListenSocket.Cl ose()

Else

Dim recv As String = ASCII.GetString (bytes, 0, numbytes)

'Clear the buffer
Array.Clear(byt es, 0, bytes.Length)

'Begin Receive Again
ClientSocket.Be ginReceive(byte s, 0, bytes.Length,
SocketFlags.Non e, AddressOf ListenReceiveCa llBack, bytes)

End If

End Sub

#End Region

[Dragon]

Re: TCPListener


"iwdu15" <iwdu15@discuss ions.microsoft. com> ÓÏÏÂÝÉÌ/ÓÏÏÂÝÉÌÁ × ÎÏ×ÏÓÔÑÈ
ÓÌÅÄÕÀÝÅÅ: news:B2EF8CEA-0254-4F26-AC05-A347DE415E34@mi crosoft.com...[color=blue]
> well that wasnt all my code, that was just relavant to the listening[/color]
paert,[color=blue]
> if u want i can show all my code, but homeip is used in the formload[/color]
event to[color=blue]
> get the IP address from the computer its running on, and clientsocket[/color]
wis[color=blue]
> used to send the connect request in my other code and the code[/color]
endrecieve is[color=blue]
> in there, il just list all my code here:[/color]

Okay, forget point #1 8=].
But look again at other my suggestions and try to implement them.

Roman

[iwdu15]

Re: TCPListener

ok, i tried binding the ListenSocket to an endpoint, and it gives an object
reference exception, heres the code, and homeIP and me.txtlistenip. text both
have values in them:

Private Sub btnlisten_Click (ByVal sender As System.Object, ByVal e As
System.EventArg s) Handles btnlisten.Click

Call Listen(homeip, Me.txtlistenpor t.Text)

End Sub

Private Sub Listen(ByVal IP As IPAddress, ByVal port As Integer)

Dim ep As New Net.IPEndPoint( IP, port)

ListenSocket.Bi nd(ep)

ListenSocket.Li sten(50)

ListenSocket = New Net.Sockets.Soc ket(AddressFami ly.InterNetwork ,
SocketType.Stre am, ProtocolType.Tc p)

ListenSocket.Be ginAccept(Addre ssOf ListenCallBack, Nothing)

End Sub

[Dragon]

Re: TCPListener

> Private Sub Listen(ByVal IP As IPAddress, ByVal port As Integer)[color=blue]
>
> Dim ep As New Net.IPEndPoint( IP, port)
>
> ListenSocket.Bi nd(ep)
>
> ListenSocket.Li sten(50)
>
> ListenSocket = New[/color]
Net.Sockets.Soc ket(AddressFami ly.InterNetwork ,[color=blue]
> SocketType.Stre am, ProtocolType.Tc p)
>
> ListenSocket.Be ginAccept(Addre ssOf ListenCallBack, Nothing)
>
> End Sub[/color]

Eh, you should first create a socket *before* calling methods on it,
shouldn't you?

ListenSocket = New Socket(...)
ListenSocket.Bi nd(...)
ListenSocket.Li sten(...)
ListenSocket.Be ginAccept(...)

Roman

[iwdu15]

Re: TCPListener

whups, n00b error there, thanks for pointing that out, but now i havbe a
problem. il show the code but one computer says its connected while the other
does not. the computer listening throws an exception saying it cant recieve
data when its not connected while the other computer says its
connected....he res the code, thanks for all your help

Imports System.Net.Sock ets
Imports System.Net

Public Class Form1
Inherits System.Windows. Forms.Form

#Region " Windows Form Designer generated code "

Public Sub New()
MyBase.New()

'This call is required by the Windows Form Designer.
InitializeCompo nent()

'Add any initialization after the InitializeCompo nent() call

End Sub

'Form overrides dispose to clean up the component list.
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
If disposing Then
If Not (components Is Nothing) Then
components.Disp ose()
End If
End If
MyBase.Dispose( disposing)
End Sub

'Required by the Windows Form Designer
Private components As System.Componen tModel.IContain er

'NOTE: The following procedure is required by the Windows Form Designer
'It can be modified using the Windows Form Designer.
'Do not modify it using the code editor.
Friend WithEvents btnconnect As System.Windows. Forms.Button
Friend WithEvents txtport As System.Windows. Forms.TextBox
Friend WithEvents txtIP As System.Windows. Forms.TextBox
Friend WithEvents btnlisten As System.Windows. Forms.Button
Friend WithEvents txtlistenport As System.Windows. Forms.TextBox
Friend WithEvents GroupBox1 As System.Windows. Forms.GroupBox
Friend WithEvents GroupBox2 As System.Windows. Forms.GroupBox
Friend WithEvents rtbinfo As System.Windows. Forms.RichTextB ox
Friend WithEvents rtbsend As System.Windows. Forms.RichTextB ox
Friend WithEvents btnsend As System.Windows. Forms.Button
Friend WithEvents txtsend As System.Windows. Forms.TextBox
Friend WithEvents btndisconnect As System.Windows. Forms.Button
<System.Diagnos tics.DebuggerSt epThrough()> Private Sub
InitializeCompo nent()
Me.btnconnect = New System.Windows. Forms.Button
Me.txtport = New System.Windows. Forms.TextBox
Me.txtIP = New System.Windows. Forms.TextBox
Me.btnlisten = New System.Windows. Forms.Button
Me.txtlistenpor t = New System.Windows. Forms.TextBox
Me.GroupBox1 = New System.Windows. Forms.GroupBox
Me.btndisconnec t = New System.Windows. Forms.Button
Me.GroupBox2 = New System.Windows. Forms.GroupBox
Me.rtbinfo = New System.Windows. Forms.RichTextB ox
Me.rtbsend = New System.Windows. Forms.RichTextB ox
Me.btnsend = New System.Windows. Forms.Button
Me.txtsend = New System.Windows. Forms.TextBox
Me.GroupBox1.Su spendLayout()
Me.GroupBox2.Su spendLayout()
Me.SuspendLayou t()
'
'btnconnect
'
Me.btnconnect.L ocation = New System.Drawing. Point(16, 56)
Me.btnconnect.N ame = "btnconnect "
Me.btnconnect.T abIndex = 0
Me.btnconnect.T ext = "Connect"
'
'txtport
'
Me.txtport.Loca tion = New System.Drawing. Point(112, 56)
Me.txtport.Name = "txtport"
Me.txtport.Size = New System.Drawing. Size(56, 20)
Me.txtport.TabI ndex = 1
Me.txtport.Text = "5190"
'
'txtIP
'
Me.txtIP.Locati on = New System.Drawing. Point(32, 24)
Me.txtIP.Name = "txtIP"
Me.txtIP.TabInd ex = 2
Me.txtIP.Text = "IP"
'
'btnlisten
'
Me.btnlisten.Lo cation = New System.Drawing. Point(24, 48)
Me.btnlisten.Na me = "btnlisten"
Me.btnlisten.Ta bIndex = 3
Me.btnlisten.Te xt = "Listen"
'
'txtlistenport
'
Me.txtlistenpor t.Location = New System.Drawing. Point(120, 48)
Me.txtlistenpor t.Name = "txtlistenp ort"
Me.txtlistenpor t.Size = New System.Drawing. Size(56, 20)
Me.txtlistenpor t.TabIndex = 4
Me.txtlistenpor t.Text = "5190"
'
'GroupBox1
'
Me.GroupBox1.Co ntrols.Add(Me.t xtport)
Me.GroupBox1.Co ntrols.Add(Me.t xtIP)
Me.GroupBox1.Co ntrols.Add(Me.b tnconnect)
Me.GroupBox1.Co ntrols.Add(Me.b tndisconnect)
Me.GroupBox1.Lo cation = New System.Drawing. Point(8, 8)
Me.GroupBox1.Na me = "GroupBox1"
Me.GroupBox1.Si ze = New System.Drawing. Size(208, 88)
Me.GroupBox1.Ta bIndex = 5
Me.GroupBox1.Ta bStop = False
Me.GroupBox1.Te xt = "Connect"
'
'btndisconnect
'
Me.btndisconnec t.Location = New System.Drawing. Point(16, 56)
Me.btndisconnec t.Name = "btndisconn ect"
Me.btndisconnec t.TabIndex = 9
Me.btndisconnec t.Text = "Disconnect "
Me.btndisconnec t.Visible = False
'
'GroupBox2
'
Me.GroupBox2.Co ntrols.Add(Me.b tnlisten)
Me.GroupBox2.Co ntrols.Add(Me.t xtlistenport)
Me.GroupBox2.Lo cation = New System.Drawing. Point(8, 104)
Me.GroupBox2.Na me = "GroupBox2"
Me.GroupBox2.Si ze = New System.Drawing. Size(208, 88)
Me.GroupBox2.Ta bIndex = 0
Me.GroupBox2.Ta bStop = False
Me.GroupBox2.Te xt = "Listen"
'
'rtbinfo
'
Me.rtbinfo.Loca tion = New System.Drawing. Point(16, 200)
Me.rtbinfo.Name = "rtbinfo"
Me.rtbinfo.Read Only = True
Me.rtbinfo.Size = New System.Drawing. Size(208, 152)
Me.rtbinfo.TabI ndex = 6
Me.rtbinfo.Text = ""
'
'rtbsend
'
Me.rtbsend.Loca tion = New System.Drawing. Point(256, 184)
Me.rtbsend.Name = "rtbsend"
Me.rtbsend.Size = New System.Drawing. Size(296, 168)
Me.rtbsend.TabI ndex = 7
Me.rtbsend.Text = ""
'
'btnsend
'
Me.btnsend.Loca tion = New System.Drawing. Point(320, 40)
Me.btnsend.Name = "btnsend"
Me.btnsend.TabI ndex = 3
Me.btnsend.Text = "Send"
'
'txtsend
'
Me.txtsend.Loca tion = New System.Drawing. Point(320, 72)
Me.txtsend.Name = "txtsend"
Me.txtsend.TabI ndex = 8
Me.txtsend.Text = "TextBox1"
'
'Form1
'
Me.AutoScaleBas eSize = New System.Drawing. Size(5, 13)
Me.ClientSize = New System.Drawing. Size(560, 357)
Me.Controls.Add (Me.txtsend)
Me.Controls.Add (Me.rtbsend)
Me.Controls.Add (Me.GroupBox1)
Me.Controls.Add (Me.GroupBox2)
Me.Controls.Add (Me.rtbinfo)
Me.Controls.Add (Me.btnsend)
Me.Name = "Form1"
Me.Text = "Form1"
Me.GroupBox1.Re sumeLayout(Fals e)
Me.GroupBox2.Re sumeLayout(Fals e)
Me.ResumeLayout (False)

End Sub

#End Region

#Region "Declaratio ns"

Dim homeip As Net.IPAddress
Dim ClientSocket As Net.Sockets.Soc ket
Dim ASCII As New System.Text.ASC IIEncoding

Dim ListenSocket As Net.Sockets.Soc ket

#End Region

#Region "Connect"

Private Sub Form1_Load(ByVa l sender As System.Object, ByVal e As
System.EventArg s) Handles MyBase.Load

homeip =
Net.Dns.GetHost ByName(Net.Dns. GetHostName).Ad dressList.GetVa lue(0)

Me.Text = homeip.ToString

End Sub

Private Sub btnconnect_Clic k(ByVal sender As System.Object, ByVal e As
System.EventArg s) Handles btnconnect.Clic k

Dim addr As Net.IPAddress =
Net.Dns.Resolve (Me.txtIP.Text) .AddressList(0)

If Not addr Is Nothing Then
'Create IP endpoint
Dim EP As New Net.IPEndPoint( addr, CInt(Me.txtport .Text))

'create socket
ClientSocket = New
Net.Sockets.Soc ket(Net.Sockets .AddressFamily. InterNetwork,
Net.Sockets.Soc ketType.Stream, Net.Sockets.Pro tocolType.Tcp)

'Connect
ClientSocket.Be ginConnect(EP, AddressOf ConnectCallBack , Nothing)
' ClientSocket.Se nd(

End If

End Sub

Private Sub ConnectCallBack (ByVal ar As IAsyncResult)

Try
ClientSocket.En dConnect(ar)

Dim dlg As New NoParamsDelegat e(AddressOf ConnectedUI)

Me.Invoke(dlg)

'Begin Receiveing Data
Dim bytes(4095) As Byte
ClientSocket.Be ginReceive(byte s, 0, bytes.Length,
SocketFlags.Non e, AddressOf ReceiveCallBack , bytes)

Catch ex As Exception
Me.rtbinfo.Text += vbNewLine & ex.Message & vbNewLine
End Try

End Sub

Private Delegate Sub NoParamsDelegat e()

Private Sub ConnectedUI()

Me.rtbinfo.Text += vbNewLine & "Connected" & vbNewLine

Me.btnsend.Enab led = True
Me.rtbsend.Focu s()

End Sub

Private Sub DisconnectedUI( )

Me.rtbinfo.Text += vbNewLine & "Disconnect ed" & vbNewLine

Me.btnconnect.V isible = True
Me.btndisconnec t.Visible = False
Me.btnsend.Enab led = False
Me.btnconnect.F ocus()

End Sub

Private Sub ReceiveCallBack (ByVal ar As IAsyncResult)

Dim bytes() As Byte = CType(ar.AsyncS tate, Byte())
Dim numbytes As Int32 = ClientSocket.En dReceive(ar)

If numbytes = 0 Then
ClientSocket.Sh utdown(SocketSh utdown.Both)
ClientSocket.Cl ose()

Dim dlg As New NoParamsDelegat e(AddressOf DisconnectedUI)

Me.Invoke(dlg)
Else
Dim recv As String = ASCII.GetString (bytes, 0, numbytes)

'Clear the buffer
Array.Clear(byt es, 0, bytes.Length)

'Show in UI
Dim dlg As New OneStringDelega te(AddressOf DisplayReceived Data)
Dim args() As Object = {recv}

Me.Invoke(dlg, args)

'Begin Receive Again
ClientSocket.Be ginReceive(byte s, 0, bytes.Length,
SocketFlags.Non e, AddressOf ReceiveCallBack , bytes)

End If

End Sub

Private Delegate Sub OneStringDelega te(ByVal data As String)

Private Sub btnsend_Click(B yVal sender As System.Object, ByVal e As
System.EventArg s) Handles btnsend.Click

Try
If sender Is ClientSocket Then
Dim bytes() As Byte = ASCII.GetBytes( Me.txtsend.Text )
ClientSocket.Se nd(bytes)
ElseIf sender Is ListenSocket Then
Dim bytes() As Byte = ASCII.GetBytes( Me.txtsend.Text )
ListenSocket.Se nd(bytes)
End If
Catch ex As Exception
Me.rtbinfo.Text += vbNewLine & ex.Message & vbNewLine
End Try

End Sub

#End Region

#Region "Listen"

Private Sub btnlisten_Click (ByVal sender As System.Object, ByVal e As
System.EventArg s) Handles btnlisten.Click

Me.btndisconnec t.Visible = True
Me.btnconnect.V isible = False
Call Listen(homeip, Me.txtlistenpor t.Text)

End Sub

Private Sub Listen(ByVal IP As IPAddress, ByVal port As Integer)

Dim ep As New Net.IPEndPoint( IP, port)

ListenSocket = New Net.Sockets.Soc ket(AddressFami ly.InterNetwork ,
SocketType.Stre am, ProtocolType.Tc p)
ListenSocket.Bi nd(ep)
ListenSocket.Li sten(50)
ListenSocket.Be ginAccept(Addre ssOf ListenCallBack, Nothing)

End Sub

Private Sub ListenCallBack( ByVal ar As IAsyncResult)

Try

ListenSocket.En dAccept(ar)

'Begin Receiveing Data
Dim bytes(4095) As Byte
ListenSocket.Be ginReceive(byte s, 0, bytes.Length,
SocketFlags.Non e, AddressOf ListenReceiveCa llBack, bytes)

Catch ex As Exception
Me.rtbinfo.Text += vbNewLine & ex.Message & vbNewLine
End Try

End Sub

Private Sub ListenReceiveCa llBack(ByVal ar As IAsyncResult)

Dim bytes() As Byte = CType(ar.AsyncS tate, Byte())
Dim numbytes As Int32 = ListenSocket.En dReceive(ar)

If numbytes = 0 Then

ListenSocket.Sh utdown(SocketSh utdown.Both)
ListenSocket.Cl ose()

Else

Dim recv As String = ASCII.GetString (bytes, 0, numbytes)

'Clear the buffer
Array.Clear(byt es, 0, bytes.Length)

'Begin Receive Again
ListenSocket.Be ginReceive(byte s, 0, bytes.Length,
SocketFlags.Non e, AddressOf ListenReceiveCa llBack, bytes)

End If

End Sub

#End Region


Private Sub DisplayReceived Data(ByVal data As String)

With Me.rtbsend

.SelectionStart = .Text.Length
.SelectedText = data

End With

End Sub

End Class

[iwdu15]

Re: TCPListener

ok, this is driving me crazy, i get this error on my comp :

A request to send or receive data was disallowed because the socket is not
connected and (when sending on a datagram socket using a sendto call) no
address was supplied

and a false connection state while the other comp has a "true" connection
state and says its connected....wt f is going on!!! lol

[Dragon]

Re: TCPListener

Okay, point #1 done. Now let's move on #3 & #4 8=].
It seems that you misunderstand how the listening works.

The Socket.EndAccep t() (.Accept()) method returns a *new* socket. This
new socket is *connected* to another computer and is used to
send/receive data. First socket is still *listening* and can be used to
accept new connections; if you don't want them, call it's .Close()
method. You can't call .Receive() on first socket, because it *is not*
connected.

See my pre-pre-previous response, points #3, #4.

Roman

[iwdu15]

Re: TCPListener

ooohhhhh....tha t makes so much more sense, so then in order to send data to
the other computer do i create a new socket and just call the "begin send"
method? will the second socket already be connected? thanks for all your help

[Wicksy]

Re: TCPListener

You dont need to create a new socket...
One was created for you and returned by the ListenSocket.Be ginAccept()
method.
eg. (quick & dirty):

dim x as Socket
x = ListenSocket.Be ginAccept() ' will assign a new socket to x

You can now use x to send/receive. Your ListenSocket is also still there,
listening away.
Usually for a synchronous server application you put the whole lot in a
continuous loop:

while true

dim x as Socket
x = ListenSocket.Ac cept() ' will assign a new socket to x

'do stuff with x
x.close()

end while


HTH.


"iwdu15" <iwdu15@discuss ions.microsoft. com> wrote in message
news:3E8D4D68-A21B-481A-9666-386E913F0469@mi crosoft.com...[color=blue]
> ooohhhhh....tha t makes so much more sense, so then in order to send data
> to
> the other computer do i create a new socket and just call the "begin send"
> method? will the second socket already be connected? thanks for all your
> help[/color]

[iwdu15]

Re: TCPListener

ok that helps alot, thanks, but what about the clientsocket that tried to
connect to the listening socket, does that one create a new socket too?
thanks for your help