VB.NET局域网服务器与客户端通信实现

'服务器代码i
Imports System.Net
Imports System.Net.Sockets
Imports System.Threading
Imports System.Text
Imports System.Collections.Generic
Imports System.IO
Public Class Form1
    Public LinkThread As Thread '声明一个线程，用于和客户机通讯
    Public LinkThreadB As Thread '声明一个线程，用于和客户机通讯
    Public ListenSocket As Socket '声明一个Socket用于侦听
    Public data As String = String.Empty
    Public nsStream As NetworkStream
    Public swwrite As StreamWriter
    Public SocketLis As Socket
    Public Dic As Dictionary(Of String, Socket) = New Dictionary(Of String, Socket)
    Private Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles Button1.Click
        If Button1.Text = "开始侦听" Then  '判断是否正在侦听 '获取要侦听的IP地址和端口

            Dim localEndPoint As New IPEndPoint(Net.IPAddress.Parse(TextBox1.Text), TextBox2.Text)
            '初始化Socket为IP4的版本 TCP协议
            ListenSocket = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
            ToolStripStatusLabel1.Text = "开始侦听端口"
            Button1.Text = "停止侦听" '更改侦听按钮的显示
            Button1.BackColor = Color.Green    '绑定端口
            ListenSocket.Bind(localEndPoint) '开始监听
            ShowMsg("开始侦听端口！ ") '显示文本信息
            ListenSocket.Listen(100) '最多连接100个客户端
            LinkThread = New Thread(AddressOf listen)  '创建一个线程并且启动线程开始侦听端口
            LinkThread.IsBackground = True   '设置为后台进程

            LinkThread.Start(ListenSocket)  '给线程传输一个参数,类型为Socket

        Else
            Button1.Text = "开始侦听" '更改侦听按钮的显示
            Button1.BackColor = SystemColors.Control

            Try '关闭Socket，并且结束线程（必须先关Socket再结束线程，否则出错）
                ListenSocket.Dispose()
                ListenSocket.Close()
                LinkThread.Abort()

            Catch
            End Try
            ShowMsg("停止侦听端口！")
            ToolStripStatusLabel1.Text = "停止侦听端口！"
        End If

    End Sub
    Private Sub listen(ByVal s As Socket)

        While True
            Try

                '新建一个Socket，并且等待客户端连接
                SocketLis = s.Accept() '等待接收客户端的连接
                Dic.Add(SocketLis.RemoteEndPoint.ToString, SocketLis) '把连接到的客户端IP和端口存到键值里
                ComboBox1.Items.Add(SocketLis.RemoteEndPoint.ToString) '把连接到的客户端IP和端口存到下拉框里
                ComboBox2.Items.Add(SocketLis.RemoteEndPoint.AddressFamily.ToString)
                '显示连接的客户端IP和端口
                ShowMsg("客户机已连接！" + SocketLis.RemoteEndPoint.ToString)