TcpListener.BeginAcceptTcpClient(AsyncCallback, Object) TcpListener.BeginAcceptTcpClient(AsyncCallback, Object) TcpListener.BeginAcceptTcpClient(AsyncCallback, Object) TcpListener.BeginAcceptTcpClient(AsyncCallback, Object) Method

Definition

Begins an asynchronous operation to accept an incoming connection attempt.

public:
 IAsyncResult ^ BeginAcceptTcpClient(AsyncCallback ^ callback, System::Object ^ state);
public IAsyncResult BeginAcceptTcpClient (AsyncCallback callback, object state);
member this.BeginAcceptTcpClient : AsyncCallback * obj -> IAsyncResult
Public Function BeginAcceptTcpClient (callback As AsyncCallback, state As Object) As IAsyncResult
Parameters
callback
AsyncCallback AsyncCallback AsyncCallback AsyncCallback

An AsyncCallback delegate that references the method to invoke when the operation is complete.

state
Object Object Object Object

A user-defined object containing information about the accept operation. This object is passed to the callback delegate when the operation is complete.

Returns

An IAsyncResult that references the asynchronous creation of the TcpClient.

Exceptions

An error occurred while attempting to access the socket.

Examples

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;

    // Accept one client connection asynchronously.
public:
    static void DoBeginAcceptTcpClient(TcpListener^ listener)
    {
        // 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(
            gcnew AsyncCallback(DoAcceptTcpClientCallback),
            listener);

        // Wait until a connection is made and processed before
        // continuing.
        TcpClientConnected->WaitOne();
    }

    // Process the client connection.
public:
    static void DoAcceptTcpClientCallback(IAsyncResult^ result)
    {
        // Get the listener that handles the client request.
        TcpListener^ listener = (TcpListener^) result->AsyncState;

        // End the operation and display the received data on
        // the console.
        TcpClient^ client = listener->EndAcceptTcpClient(result);

        // 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();

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

// Accept one client connection asynchronously.
public static void DoBeginAcceptTcpClient(TcpListener 
    listener)
{
    // 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(DoAcceptTcpClientCallback), 
        listener);

    // Wait until a connection is made and processed before 
    // continuing.
    tcpClientConnected.WaitOne();
}

// 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.
    tcpClientConnected.Set();

}
' 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 'DoBeginAcceptTcpClient


' 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 'DoAcceptTcpClientCallback
 

Remarks

The asynchronous BeginAcceptTcpClient operation must be completed by calling the EndAcceptTcpClient method. Typically, the method is invoked by the callback delegate.

This method does not block until the operation completes. To block until the operation completes, use the AcceptTcpClient method.

For detailed information about using the asynchronous programming model, see Calling Synchronous Methods Asynchronously.

Note

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.

Note

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

Applies to