|
这是用VB.net实现的一个简单的P2P示例.利用了UDP打洞技术.分服务器端跟客户端.服务器端负责登陆记录用户的IP和端口及转发打洞消息.(相关技术在CSDN搜一下.有很多的.).原理到处都有,这里就没有贴出来.这里贴出了VB.net的代码.供初学者交流.也欢迎高手点评... 服务器端在启动成功后.输入help可以查看到服务器相关命令. 客户端在登陆成功后.输入help可以查看客户端相关命令.(登陆时用户名随便.) 以下是服务器端: Imports System.Net
Imports System.Net.Sockets
Imports System.Text
Imports System.Threading
Imports System.Collections Module myUDPServer #Region "全局变量" Dim ServerSocket As New Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp)
Dim ipep As IPEndPoint = New IPEndPoint(IPAddress.Any, 11000) Dim htUserList As New Hashtable ''''用来保存在线用户和用户的"IP和端口" Dim userName(0) As String
Dim userIPEP(0) As IPEndPoint
Dim userTime(0) As Integer Dim timerDelegate As New TimerCallback(AddressOf onLineTimeOut) #End Region #Region "参数" ''''以下是客户端到服务器端的消息开头
Const LOGININ As String = "10" ''''请求登陆的消息|||消息形式:10+自己的用户名
Const LOGINOUT As String = "11" ''''请求登出的消息|||消息形式:11+自己的用户名
Const GETULIST As String = "12" ''''请求获得在线用户列表|||消息形式:12
Const P2PCONN As String = "13" ''''请求P2P连接的消息|||消息形式:13+自己的用户名+|+对方的用户名
Const HOLDLINE As String = "14" ''''保持连接.|||消息开式:14+自己的用户名 ''''以下是服务器到客户端的消息开头
Const HVUSER As String = "20" ''''用户名已存在
Const GETUSER As String = "21" ''''在线用户列表|||消息格式:21+用户名+EP
Const MAKHOLD As String = "22" ''''打洞命令|||消息格式:22+IP
Const LOGINOK As String = "23" ''''登陆成功
Const SERVCLS As String = "24" ''''服务器关闭
Const MSGEND As String = "25" ''''消息结束 ''''以下是服务器端的命名
Const EXITPRO As String = "EXIT" ''''退出命令
Const SHOWULIST As String = "SHOWUSER" ''''显示在线用户
Const HELP As String = "HELP" ''''显示帮助 #End Region #Region "方法" ''''主函数,程序入口
Sub Main() ''''获得服务器的IP地址
Dim addressList As System.Net.IPAddress() = Dns.GetHostByName(Dns.GetHostName()).AddressList
Dim ServerIP As IPAddress = addressList(0) ServerSocket.Bind(ipep)
Console.WriteLine("服务器正在启动....")
Console.WriteLine("服务器IP:" & ServerIP.ToString & " 正在监听" & ipep.Port.ToString & "端口")
Dim listenTH As New Thread(AddressOf listen)
listenTH.Start() ''''启用监听的线程
Console.WriteLine("服务器启动成功.....") Dim timer As New Timer(timerDelegate, Nothing, 0, 5000) Dim SVInput As String
While True
Console.Write("Server>")
SVInput = Console.ReadLine().ToUpper
Select Case SVInput
Case EXITPRO
listenTH.Abort()
ServerSocket.Close()
Exit Sub
Case SHOWULIST
showUser()
Case HELP
Console.Write("*********************************" & Chr(10) & Chr(13) & "exit:输出当前程序" & Chr(10) & Chr(13) & "showuser:显示当前在线用户例表" & Chr(10) & Chr(13) & "help:显示帮助" & Chr(10) & Chr(13) & "*********************************" & Chr(10) & Chr(13))
Case Else
Console.WriteLine("*********************************" & Chr(10) & Chr(13) & "笨瓜,你输入的不是有效的命令." & Chr(10) & Chr(13) & "*********************************")
End Select
End While
End Sub
''''打印在线用户
Sub showUser()
Dim hava As Boolean = False
If userName.Length <> 0 Then
Dim i As Integer
For i = 1 To userName.Length - 1
If userName(i) <> "" Then
hava = True
Exit For
End If
Next
If hava = False Then
Console.WriteLine("*********************************" & Chr(10) & Chr(13) & "当前没有用户在线" & Chr(10) & Chr(13) & "*********************************")
Exit Sub
End If
Console.WriteLine("*********************************")
For i = 1 To userName.Length - 1
If userName(i) <> "" Then
Console.WriteLine("用户名:" & userName(i) & " 地址:" & userIPEP(i).ToString)
End If
Next
Console.WriteLine("*********************************")
Else
Console.WriteLine("*********************************" & Chr(10) & Chr(13) & "当前没有用户在线" & Chr(10) & Chr(13) & "*********************************")
End If
End Sub ''''服务器监听函数
Sub listen() While True Try
Dim recv As Integer = 0
Dim data As [Byte]() = New Byte(1024) {}
Dim sender As New IPEndPoint(IPAddress.Any, 0)
Dim tempRemoteEP As EndPoint = CType(sender, EndPoint)
recv = ServerSocket.ReceiveFrom(data, tempRemoteEP) [1] [2] [3] [4] [5] [6] [7] [8] 下一页 | 
