服务端
Imports System.Net
Imports System.Net.Sockets
Imports System.Threading
Imports System.Text
Public Class Form1
    Dim s As Socket
    Dim t As Thread

    Delegate Sub setTextGetBack(ByVal arg1 As Integer, ByVal arg2 As Byte()) ''声明委托，异步调用

    Private Sub setText(ByVal arg1 As Integer, ByVal arg2 As Byte())
        If Me.ListBox1.InvokeRequired Then
            Dim stg As setTextGetBack = New setTextGetBack(AddressOf setText)
            Me.Invoke(stg, New Object() {arg1, arg2})
        Else
            Me.ListBox1.Items.Insert(arg1, Encoding.Unicode.GetString(arg2))
        End If

    End Sub

    Public Sub waitData()
        s = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp) '‘声明一个socket，使用tcp协议
        Dim localEndPoint As New IPEndPoint(IPAddress.Parse("172.17.53.90"), 1024)
        s.Bind(localEndPoint) '‘绑定到一台服务器
        s.Listen(100) '‘侦听，最多可以侦听100连接

        While True
            Dim bytes(1024) As Byte '‘用来存储接收的数据字节
            Dim ss As Socket = s.Accept() '‘若接收到，则创建一个新的socket与之连接
            ss.Receive(bytes) '‘接收数据
            setText(0, bytes) '‘处理接收到的数据
        End While

    End Sub
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        t = New Thread(AddressOf waitData)
        t.Start()
        Dim bytes(1024) As Byte
        bytes = Encoding.Unicode.GetBytes("~~~~~~~~~~~~~~~~服务器开始启动~~~~~~~~~~~~~~~~")
        Button1.Enabled = False
        setText(0, bytes)
        Try
         

            's.Close()
            't.Abort()
        Catch ex As Exception
            MsgBox(ex.Message, MsgBoxStyle.Exclamation, "错误提示")
        Finally

        End Try
    End Sub

    Private Sub Form1_FormClosing(ByVal sender As System.Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles MyBase.FormClosing
        Try

        Catch ex As Exception
            MsgBox(ex.Message, MsgBoxStyle.Exclamation, "错误提示")
        Finally
            s.Close() '‘关闭socket
            t.Abort() ''中止线程
        End Try
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Try
            s.Close()
            t.Abort()
            Button1.Enabled = True
            Button2.Enabled = False
        Catch ex As Exception
            MsgBox(ex.Message, MsgBoxStyle.Exclamation, "错误提示")
        End Try

    End Sub
End Class


客户端
Imports System.Threading
Imports System.Text
Imports System.Net
Imports System.Net.Sockets
Public Class Form1

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Try
            Dim s As Socket = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
            Dim endPint As IPEndPoint = New IPEndPoint(IPAddress.Parse("172.17.53.90"), 1024)
            s.Connect(endPint)
            s.Send(Encoding.Unicode.GetBytes(TextBox1.Text))
            s.Close()
        Catch ex As Exception

        End Try
    End Sub
End Class