[vb2010]Scambio di dati socket asincroni

Imports System.Net
Imports System.Net.Sockets

Public Class frmClient

   '------------------------------------------CODICE CLIENT ------------------------------------------------------------
   Dim client As Socket
   Dim bytedata(1023) As Byte
   Dim messaggio As String

   Private Sub cmdConnetti_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdConnetti.Click
       client = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
       Dim IpAddress As IPAddress = IpAddress.Parse("127.0.0.1")
       Dim IpEndPoint As IPEndPoint = New IPEndPoint(IpAddress, 1200)
       client.BeginConnect(IpEndPoint, New AsyncCallback(AddressOf onconnect), Nothing)
   End Sub

   Private Sub onconnect(ByVal ar As IAsyncResult)
       client.EndConnect(ar)
       client.BeginReceive(bytedata, 0, bytedata.Length, SocketFlags.None, New AsyncCallback(AddressOf onreceive), client)
   End Sub

   Private Sub onreceive(ByVal ar As IAsyncResult)
       Dim client As Socket = ar.AsyncState
       client.EndReceive(ar)
       Dim bytericevuti As Byte() = bytedata
       Dim message As String = System.Text.ASCIIEncoding.ASCII.GetString(bytericevuti)
       Read(message, RichTxtConnessione)
       client.BeginReceive(bytedata, 0, bytedata.Length, SocketFlags.None, New AsyncCallback(AddressOf onreceive), client)
   End Sub

   Delegate Sub _read(ByVal msg As String, ByVal richtxt As Object)
   Private Sub Read(ByVal msg As String, ByVal richtxt As Object)
       If InvokeRequired Then
           Invoke(New _read(AddressOf Read), msg, richtxt)
           Exit Sub
       End If
       richtxt.text = msg
   End Sub

   Private Sub send(ByVal msg As String, ByVal client As Socket)
       Dim sendbyte As Byte() = System.Text.ASCIIEncoding.ASCII.GetBytes(msg)
       client.BeginSend(sendbyte, 0, sendbyte.Length, SocketFlags.None, New AsyncCallback(AddressOf onsend), client)
   End Sub
   Private Sub onsend(ByVal ar As IAsyncResult)
       Dim client As Socket = ar.AsyncState
       Dim server As Socket = ar.AsyncState

       client.EndSend(ar)

   End Sub


   Private Sub frmClient_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
       frmServer.Show()
   End Sub

   '------------------------------------------- fine codice client ---------------------------------------------------

   Private Sub cmdInfo_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdInfo.Click
       send("info", client)
   End Sub
End Class

Public Class frmServer

   '----------------------------------------------------- Codice Server----------------------------------------
   Dim client As Socket
   Dim server As Socket
   Dim bytedata(1023) As Byte
   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 IpEndPoint As IPEndPoint = New IPEndPoint(IPAddress.Any, 1200)

       server.Bind(IpEndPoint)
       server.Listen(3)
       server.BeginAccept(New AsyncCallback(AddressOf onaccept), Nothing)
   End Sub

   Private Sub onaccept(ByVal ar As IAsyncResult)
       client = server.EndAccept(ar)
       server.BeginAccept(New AsyncCallback(AddressOf onaccept), Nothing)
       addclient(client)
       client.BeginReceive(bytedata, 0, bytedata.Length, SocketFlags.None, New AsyncCallback(AddressOf onreceive), client)
   End Sub
   Delegate Sub _addclient(ByVal client As Socket)

   Private Sub addclient(ByVal client As Socket)
       If InvokeRequired Then
           Invoke(New _addclient(AddressOf addclient), client)
           Exit Sub
       End If

       Dim lvi As New ListViewItem(client.LocalEndPoint.ToString)
       lvi.Tag = client
       ListView1.Items.Add(lvi)
   End Sub

   Private Sub send(ByVal msg As String, ByVal client As Socket)
       Dim sendbyte As Byte() = System.Text.ASCIIEncoding.ASCII.GetBytes(msg)
       client.BeginSend(sendbyte, 0, sendbyte.Length, SocketFlags.None, New AsyncCallback(AddressOf onsend), client)
   End Sub
   Private Sub onsend(ByVal ar As IAsyncResult)
       Dim client As Socket = ar.AsyncState
       client.EndSend(ar)
   End Sub

   Private Sub onreceive(ByVal ar As IAsyncResult)
       Dim client As Socket = ar.AsyncState
       client.EndReceive(ar)
       Dim bytericevuti As Byte() = bytedata
       Dim message As String = System.Text.ASCIIEncoding.ASCII.GetString(bytericevuti)
       Read(message)
       client.BeginReceive(bytedata, 0, bytedata.Length, SocketFlags.None, New AsyncCallback(AddressOf onreceive), client)
   End Sub

   Delegate Sub _read(ByVal msg As String)
   Private Sub Read(ByVal msg As String)
       If InvokeRequired Then
           Invoke(New _read(AddressOf Read), msg)
           Exit Sub
       End If
       ListView1.Clear()
       ListView1.Items.Add(msg)
       If msg = "info" Then
           send(My.Computer.Name.ToString, client)
       End If
   End Sub

   '---------------------------------------- FINE CODICE PER CONNESSIONE -----------------------------------------------------------------------

   Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
       send("Message from server", client)
   End Sub

   Private Sub ListView1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListView1.SelectedIndexChanged

   End Sub
End Class