主题：关于TCP Socket 端口监听 的问题

 Public socket As MyClient

Public Class MyClient
Private mainfrm As Object
Public receiveThread As System.Threading.Thread
Public nStream As System.Net.Sockets.NetworkStream
Public tcp As  System.Net.Sockets.TcpClient

Public Sub New(ByVal ip As String, ByVal port As Integer, ByVal frm As Object,ByVal msg As String,ByVal msg1 As String)
mainfrm = frm
Dim server As System.Net.IPAddress = System.Net.IPAddress.Parse(ip)
tcp = New System.Net.Sockets.TcpClient()
Try
    tcp.Connect(ip, port)
Catch generatedExceptionName As Exception
    tcp = Nothing
End Try

If tcp Is Nothing Then
    MsgBox("无法连接服务器,请重试")
Else
    Dim netStream As System.Net.Sockets.NetworkStream = tcp.GetStream()
    Dim stream() As Byte = Encoding.Unicode.GetBytes(loginInfo)
    netStream.Write(stream, 0, stream.Length)   '往服务器发送登录信息
    
    Dim buffer As Byte() = New Byte(50) {}
    netStream.Read(buffer, 0, buffer.Length)   '得到回发的信息
    
    Dim connResult As String = Encoding.Unicode.GetString(buffer)
    If connResult> "" Then   '登录成功
        nStream = netStream
        receiveThread = New System.Threading.Thread(New System.Threading.ThreadStart(AddressOf ReceiveMsg))
        receiveThread.IsBackground=True
        receiveThread.Start()
    Else
        MsgBox("登录失败……")
        Return
    End If
End If
End Sub

''' <summary>
''' 接受消息的线程执行体
''' </summary>
Private Sub ReceiveMsg()
While True
    Dim packet As Byte() = New Byte(2) {}
    nStream.Read(packet, 0, packet.Length)
    Dim _cmd As String = String.Concat(packet(0), packet(1))
    
    Select Case _cmd
        '11状态,关闭客户端
        Case "11"
            mainfrm.Close()
            If receiveThread IsNot Nothing Then
                receiveThread.Abort()
            End If
            nStream.Close()
    End Select
End While
End Sub
End Class