套接字侦听和连接

Question

我设置了一个 System.Net.Sockets.Socket。我启动套接字侦听传入连接以接受套接字请求。这个相同的套接字应该能够停止监听和写入并连接到其他套接字。将套接字设置为 Listen 后，我无法让它发送连接命令。我得到这个例外：

“System.InvalidOperationException”类型的未处理异常发生在 系统.dll 附加信息：调用 Listen 方法后，您可能无法执行此操作。

如何更改其状态并允许其更改连接并返回监听？我正在使用 TCP 本地主机

Public Class SocketHandler

Private Socke As Sockets
Private connectThread As Thread
Private listenThread As Thread 
Private listening As Boolean = False

Public Sub New()
       listenThread = New Thread(Address of Listen)
       listenThread.IsBackground = True
       listenThread.Start()
End New

Private Sub Listen()
       Socke.Bind(New IPEndPoint(IPAddress.Any, Socke.Port))
       Socke.Listen(5)
       While Listening
             Dim Sock As Sockets = DirectCast(Socke.Accept(), Sockets)
             If Not Socke.Clients.Contains(Sock) Then
                  Socke.Clients.Add(Sock)
             End If
       End While
End Sub

Private Connect(ByVal sock As Sockets)
      connectThread = New Thread(Sub() Connecting(sock))
      connectThread.IsBackground = True
      connectThread.Start()
End If

Private Sub Connecting(Byval sock As Sockets)
      'Right Here is where I need to stop Listening and have the Socket connect
      Socke.Connect(sock) 'Here is where I get the Exception
      connectThread.Abort()
      'Here I need to turn the Listening back on
End Sub

Public Class Sockets : Inherits Socket
Public Port As Integer 
Public IPAddress As IPAddress
Public Clients As New List(Of Sockets)

Public Overloads Sub Connect(Byval sock as Sockets)
     Dim point As New IPEndPoint(DirectCast(socket.LocalEndPoint), IPEndPoint)
     connectDone.Reset()
     BeginConnect(point, AddressOf Callback, sock)
     connectDone.WaitOne()
End Sub

Private Sub Callback(ByVal r As IAsyncResult)
     EndConnect(r)
     connectDone.Set()
End Sub

End Class

Answer 1

你的方法是错误的。服务器套接字侦听端口，客户端尝试连接。当从客户端接收到连接时，服务器会创建另一个套接字（当 server.Accept() 返回阻塞套接字时）。

accept 调用的返回值也是一个套接字，你应该使用它来与客户端通信。我对VB不太好，但是你要编码的是你必须保存socket.Accept()的返回值：

clientSocket = server.Accept()

然后您可以在 clientSocket 变量上调用发送/接收方法。