TcpListener.EndAcceptSocket Method (IAsyncResult)

 

Asynchronously accepts an incoming connection attempt and creates a new Socket to handle remote host communication.

Namespace:   System.Net.Sockets
Assembly:  System (in System.dll)

Public Function EndAcceptSocket (
	asyncResult As IAsyncResult
) As Socket

Parameters

asyncResult
Type: System.IAsyncResult

An IAsyncResult returned by a call to the BeginAcceptSocket method.

Return Value

Type: System.Net.Sockets.Socket

A Socket.

The Socket used to send and receive data.

Exception Condition
ObjectDisposedException

The underlying Socket has been closed.

ArgumentNullException

The asyncResult parameter is null.

ArgumentException

The asyncResult parameter was not created by a call to the BeginAcceptSocket method.

InvalidOperationException

The EndAcceptSocket method was previously called.

SocketException

An error occurred while attempting to access the Socket. See the Remarks section for more information.

This method blocks until the operation is complete. To perform this operation synchronously, use the AcceptSocket method.

System_CAPS_noteNote

You can call the RemoteEndPoint property of the returned Socket to identify the remote host's network address and port number.

System_CAPS_noteNote

If you receive a SocketException, use the SocketException.ErrorCode property to obtain the specific error code and refer to the Windows Sockets version 2 API error code documentation in the MSDN library at http://msdn.microsoft.com/library/ for a detailed description of the error.

System_CAPS_noteNote

This member outputs trace information when you enable network tracing in your application. For more information, see Network Tracing in the .NET Framework.

The following code example demonstrates the use of the BeginAcceptSocket method to create and connect a socket. The callback delegate calls the EndAcceptSocket method to end the asynchronous request.

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


' Accept one client connection asynchronously.
Public Shared Sub DoBeginAcceptSocket(listener As TcpListener)
   ' Set the event to nonsignaled state.
   clientConnected.Reset()

   ' Start to listen for connections from a client.
   Console.WriteLine("Waiting for a connection...")

   ' Accept the connection. 
   ' BeginAcceptSocket() creates the accepted socket.
   listener.BeginAcceptSocket(New AsyncCallback(AddressOf DoAcceptSocketCallback), listener)
   ' Wait until a connection is made and processed before 
   ' continuing.
   clientConnected.WaitOne()
End Sub 'DoBeginAcceptSocket


' Process the client connection.
Public Shared Sub DoAcceptSocketCallback(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 clientSocket As Socket = listener.EndAcceptSocket(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.
   clientConnected.Set()
End Sub 'DoAcceptSocketCallback

.NET Framework
Available since 2.0
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