TcpListener.EndAcceptTcpClient Method (IAsyncResult)


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

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

public TcpClient EndAcceptTcpClient(
	IAsyncResult asyncResult


Type: System.IAsyncResult

An IAsyncResult returned by a call to the BeginAcceptTcpClient method.

Return Value

Type: System.Net.Sockets.TcpClient

A TcpClient.

The TcpClient used to send and receive data.

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


You can call the RemoteEndPoint property of the underlying socket (Client) to identify the remote host's network address and port number.


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 for a detailed description of the error.


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 BeginAcceptTcpClient method to create and connect a socket. The callback delegate calls the EndAcceptTcpClient method to end the asynchronous request.

// Thread signal.
public static ManualResetEvent tcpClientConnected = 
    new ManualResetEvent(false);

// Accept one client connection asynchronously.
public static void DoBeginAcceptTcpClient(TcpListener 
    // Set the event to nonsignaled state.

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

    // Accept the connection. 
    // BeginAcceptSocket() creates the accepted socket.
        new AsyncCallback(DoAcceptTcpClientCallback), 

    // Wait until a connection is made and processed before 
    // continuing.

// Process the client connection.
public static void DoAcceptTcpClientCallback(IAsyncResult ar) 
    // Get the listener that handles the client request.
    TcpListener listener = (TcpListener) ar.AsyncState;

    // End the operation and display the received data on 
    // the console.
    TcpClient client = 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.


.NET Framework
Available since 2.0
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