Question

我在VB.NET（2010）中有一项服务，它正在异步接收带有UDPClient.BeginReceive的UDP数据包。一切正常，我能够收到分组数据 - 但我无法获得发送方（或远程）端点。

有一个CallBack例程正在接收一个IAsyncResult对象，该对象由System.net.sockets.OverlappedAsyncResult表示，其中属性SocketAddress是一个字节数组，其中是发送方端口和发送方IP地址。但它只能在调试时访问 - 我在异步回调例程中使用断点。

我无法将IAsyncResult强制转换为OverlappedAsyncResult，而且我无法在设计时访问套接字地址。它给了我一个错误，意味着没有找到对象，也无法声明它。

我正在附加一个我用它的类供参考。有没有更好的方法，或者我可以获得发件人IP？

Imports System.Net
Imports System.Net.Sockets
Imports System.Text

Public Class UDPInterface
Implements IDisposable

#Region "IDisposable Support"
Private disposedValue As Boolean ' To detect redundant calls

' IDisposable
Protected Overridable Sub Dispose(disposing As Boolean)
    If Not Me.disposedValue Then
        If disposing Then
            ' TODO: dispose managed state (managed objects).
        End If

        ' TODO: free unmanaged resources (unmanaged objects) and override Finalize() below.
        ' TODO: set large fields to null.
    End If
    Me.disposedValue = True
End Sub

' TODO: override Finalize() only if Dispose(ByVal disposing As Boolean) above has code to free unmanaged resources.
'Protected Overrides Sub Finalize()
'    ' Do not change this code.  Put cleanup code in Dispose(ByVal disposing As Boolean) above.
'    Dispose(False)
'    MyBase.Finalize()
'End Sub

' This code added by Visual Basic to correctly implement the disposable pattern.
Public Sub Dispose() Implements IDisposable.Dispose
    ' Do not change this code.  Put cleanup code in Dispose(ByVal disposing As Boolean) above.
    Dispose(True)
    GC.SuppressFinalize(Me)
End Sub
#End Region

Private _EP As UdpClient
Private _RemIPEP As System.Net.IPEndPoint
Private _Port As Integer

Public Sub New(Port As Integer)
    _Port = Port
    _RemIPEP = New IPEndPoint(System.Net.IPAddress.Any, Port)
    _EP = New UdpClient
    _EP.Client.Bind(_RemIPEP)
    _EP.BeginReceive(AddressOf Receive, _EP)

End Sub

Public Sub SendPacket(Bytes As Byte())
    _EP.Send(Bytes, Bytes.Length, New IPEndPoint(System.Net.IPAddress.Broadcast, _Port))
End Sub

Private Sub Receive(rec As IAsyncResult)
    Dim RX As Byte() = _EP.EndReceive(rec, _RemIPEP)

    Debug.Print(Encoding.ASCII.GetString(RX))

    _EP.BeginReceive(AddressOf Receive, _EP)
    RaiseEvent PacketReceived(RX)

End Sub
Public Event PacketReceived(Bytes As Byte())

End Class

UDPClient开始收到数据包源地址

0 个答案: