vb.net中tcp的简单介绍

VB.NET的TCP/IP协议 怎么弄

Dim th As Threading.Thread

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2 Dim tcpl As System.Net.Sockets.TcpListener

3

4 Private Sub Form1_Load()Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

5 th = New System.Threading.Thread(New System.Threading.ThreadStart(AddressOf MyListen))

6 th.Start()

7 End Sub

8

9 Public Sub SendMessage()Sub SendMessage(ByVal IP As String, ByVal SendMsg As String)

10 Try

11 If IP "" Then

12 Dim tcpc As New System.Net.Sockets.TcpClient(IP, 5656)

13 Dim tcpStream As Net.Sockets.NetworkStream = tcpc.GetStream

14 Dim reqStream As New IO.StreamWriter(tcpStream)

15 reqStream.Write(SendMsg)

16 reqStream.Flush()

17 tcpStream.Close()

18 tcpc.Close()

19 End If

20 Catch ex As Exception

21 MsgBox(ex.Message.ToString)

22 End Try

23 End Sub

24 Private Sub MyListen()Sub MyListen()

25 Try

26 Dim ipAddress As System.Net.IPAddress = System.Net.Dns.Resolve(System.Net.Dns.GetHostName).AddressList(0)

27 tcpl = New System.Net.Sockets.TcpListener(ipAddress, 5656)

28 tcpl.Start()

29 While True

30 Dim s As System.Net.Sockets.Socket = tcpl.AcceptSocket()

31 Dim MyBuffer(1024) As Byte

32 Dim i As Integer

33 i = s.Receive(MyBuffer)

34 If i 0 Then

35 Dim lstrRec As String

36 Dim j As Integer

37 For j = 0 To i - 1

38 TextBox1.Text += Chr(MyBuffer(j)) ","

39 Next

40 End If

41 End While

42 Catch ex As Exception

43 MsgBox(ex.Message.ToString)

44 End Try

45 End Sub

46

47 Private Sub Button1_Click()Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

48 SendMessage("192.168.0.61", TextBox2.Text)

49 End Sub

vb.net TCP协议服务端ip怎么写才能使客户端能通过公网连接进来？

需要出口设备进行映射内部地址；或使用打洞技术穿透NAT,但使用TCP打洞非常困难。

参考

穿透NAT是非常困难的，因为NAT的过程中在出口路由器上的Port已经不是你定义的iPort了，具体是多少也不固定

VB.Net 关于路由器后TCP或UDP通讯问题 假设一台电脑192.168.0.1位于路由1.

端口不NAT，两个子网中的两端之间不可能通信。至少要有一方处在公网下或有路由端口映射，不必双方都映射。

建议题主找本计算机网络的书研读一下子网划分这块儿。

VB.NET 2003中 想做一个基于TCP/IP的网络通信程序

就可以了，我有一段不太成熟的代码：

Imports System.Net

Imports System.Net.Sockets

Imports System.Threading

Imports System.IO

Public Class Form1

Dim TCPListenerRun, TCPClientRun As Boolean

Dim ControlTCPClient, ServerClient As TcpClient

Dim ControlTCPListener As TcpListener

Dim TCPClientT, TCPListenerT As Thread

Private ControlStream, SControlStream As NetworkStream

Private ControlReadStream, SControlReadStream As StreamReader

Private ControlWriteStream, SControlWriteStream As StreamWriter

'异步委托

Private Delegate Sub InvokeDelegate(ByVal iMessage As String)

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

Try

If TCPListenerRun Then

TCPListenerT.Abort()

ControlTCPListener.Stop()

TCPListenerRun = False

Button1.Text = "启动服务端 "

TextBox2.AppendText( "服务器已停止！ " vbCrLf)

Else

ControlTCPListener = New TcpListener(IPAddress.Parse( "127.0.0.1 "), 13000)

ControlTCPListener.Start()

TCPListenerT = New Thread(AddressOf Listen)

TCPListenerT.Start()

TextBox2.AppendText( "等待连接... " vbCrLf)

TextBox2.AppendText( "服务器已启动！ " vbCrLf)

TCPListenerRun = True

Button1.Text = "停止服务端 "

End If

Catch ex As Exception

TextBox2.AppendText(ex.Message vbCrLf)

End Try

End Sub

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click

Try

If TCPClientRun Then

TCPClientT.Abort()

ControlTCPClient.Close()

TCPClientRun = False

Button2.Text = "启动客户端 "

Else

ControlTCPClient = New TcpClient(New IPEndPoint(IPAddress.Parse( "127.0.0.1 "), 13001))

ControlTCPClient.Connect(New IPEndPoint(IPAddress.Parse( "127.0.0.1 "), 13000))

TCPClientRun = True

Button2.Text = "停止客户端 "

TCPClientT = New Thread(AddressOf Receive)

TCPClientT.Start()

ControlStream = ControlTCPClient.GetStream()

ControlReadStream = New StreamReader(ControlStream)

ControlWriteStream = New StreamWriter(ControlStream)

End If

Catch ex As SocketException

'If ex.ErrorCode = 10048 Then

ControlTCPClient.Close()

'End If

TCPClientRun = False

Button2.Text = "启动客户端 "

TextBox2.AppendText(ex.Message vbCrLf)

End Try

End Sub

Private Sub Listen()

ServerClient = ControlTCPListener.AcceptTcpClient

TextBox2.BeginInvoke(New InvokeDelegate(AddressOf InvokeMethod_Receive), "成功连接... ")

SControlStream = ServerClient.GetStream()

SControlReadStream = New StreamReader(SControlStream)

SControlWriteStream = New StreamWriter(SControlStream)

While True

TextBox2.BeginInvoke(New InvokeDelegate(AddressOf InvokeMethod_Receive), SControlReadStream.ReadLine())

End While

End Sub

Private Sub Receive()

While True

TextBox2.BeginInvoke(New InvokeDelegate(AddressOf InvokeMethod_Receive), ControlReadStream.ReadLine())

'Console.WriteLine(ControlTCPClient.Available)

End While

End Sub

Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

TCPListenerRun = False

TCPClientRun = False

End Sub

Private Sub InvokeMethod_Receive(ByVal iMessage As String)

TextBox2.AppendText(iMessage vbCrLf)

End Sub

Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click

ControlWriteStream.WriteLine(TextBox1.Text)

ControlWriteStream.Flush()

End Sub

Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click

SControlWriteStream.WriteLine(TextBox3.Text)

SControlWriteStream.Flush()

End Sub

End Class