' Thread signal.
Public Shared tcpClientConnected As New ManualResetEvent(False)


' Accept one client connection asynchronously.
Public Shared Sub DoBeginAcceptTcpClient(listener As TcpListener)
   ' Set the event to nonsignaled state.
   tcpClientConnected.Reset()
   
   ' Start to listen for connections from a client.
   Console.WriteLine("Waiting for a connection...")
   
   ' Accept the connection. 
   ' BeginAcceptSocket() creates the accepted socket.
   listener.BeginAcceptTcpClient(New AsyncCallback(AddressOf DoAcceptTcpClientCallback), listener)
   
   ' Wait until a connection is made and processed before 
   ' continuing.
   tcpClientConnected.WaitOne()
End Sub


' Process the client connection.
Public Shared Sub DoAcceptTcpClientCallback(ar As IAsyncResult)
   ' Get the listener that handles the client request.
   Dim listener As TcpListener = CType(ar.AsyncState, TcpListener)
   
   ' End the operation and display the received data on 
   ' the console.
   Dim client As TcpClient = listener.EndAcceptTcpClient(ar)
   
   ' Process the connection here. (Add the client to a
   ' server table, read data, etc.)
   Console.WriteLine("Client connected completed")
   
   ' Signal the calling thread to continue.
   tcpClientConnected.Set()
End Sub