TcpListener.AcceptTcpClient Method
Definition
Important
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Accepts a pending connection request.
public:
System::Net::Sockets::TcpClient ^ AcceptTcpClient();public System.Net.Sockets.TcpClient AcceptTcpClient ();member this.AcceptTcpClient : unit -> System.Net.Sockets.TcpClientPublic Function AcceptTcpClient () As TcpClientReturns
A TcpClient used to send and receive data.
Exceptions
The listener has not been started with a call to Start().
Use the ErrorCode property to obtain the specific error code. When you have obtained this code, you can refer to the Windows Sockets version 2 API error code documentation for a detailed description of the error.
Examples
In the following code example, the AcceptTcpClient method is used to return a TcpClient. This TcpClient is used to communicate with the newly connected client.
/**
* This program shows how to use the TcpListener class.
* It creates a TcpListener that listens on the specified port (13000).
* To run this program at the command line you enter:
* cs_tcpserver
* Any TcpClient that wants to use this server
* has to explicitly connect to an address obtained by the combination of
* the server on which this TcpServer is running and the port 13000.
* This TcpServer simply echoes back the message sent by the TcpClient, after
* translating it into uppercase.
**/
#using <System.dll>
using namespace System;
using namespace System::IO;
using namespace System::Net;
using namespace System::Net::Sockets;
using namespace System::Text;
int main()
{
try
{
// Set the TcpListener on port 13000.
Int32 port = 13000;
TcpListener^ server = gcnew TcpListener(IPAddress::Any, port);
// Start listening for client requests.
server->Start();
// Buffer for reading data
array<Byte>^bytes = gcnew array<Byte>(256);
String^ data = nullptr;
// Enter the listening loop.
while ( true )
{
Console::Write( "Waiting for a connection... " );
// Perform a blocking call to accept requests.
// You could also use server.AcceptSocket() here.
TcpClient^ client = server->AcceptTcpClient();
Console::WriteLine( "Connected!" );
data = nullptr;
// Get a stream object for reading and writing
NetworkStream^ stream = client->GetStream();
Int32 i;
// Loop to receive all the data sent by the client.
while ( (i = stream->Read( bytes, 0, bytes->Length )) != 0 )
{
// Translate data bytes to a ASCII string.
data = System::Text::Encoding::ASCII->GetString( bytes, 0, i );
Console::WriteLine( String::Format( "Received: {0}", data ) );
// Process the data sent by the client.
data = data->ToUpper();
array<Byte>^msg = System::Text::Encoding::ASCII->GetBytes( data );
// Send back a response.
stream->Write( msg, 0, msg->Length );
Console::WriteLine( String::Format( "Sent: {0}", data ) );
}
// Shutdown and end connection
client->Close();
}
}
catch ( SocketException^ e )
{
Console::WriteLine( "SocketException: {0}", e );
}
Console::WriteLine( "\nHit enter to continue..." );
Console::Read();
}
/**
* The following sample is intended to demonstrate how to use a
* TcpListener for synchronous communcation with a TCP client
* It creates a TcpListener that listens on the specified port (13000).
* Any TCP client that wants to use this TcpListener has to explicitly connect
* to an address obtained by the combination of the server
* on which this TcpListener is running and the port 13000.
* This TcpListener simply echoes back the message sent by the client
* after translating it into uppercase.
* Refer to the related client in the TcpClient class.
*/
using System;
using System.Text;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Threading;
public class TcpListenerSample
{
static void Main(string[] args)
{
try
{
// set the TcpListener on port 13000
int port = 13000;
TcpListener server = new TcpListener(IPAddress.Any, port);
// Start listening for client requests
server.Start();
// Buffer for reading data
byte[] bytes = new byte[1024];
string data;
//Enter the listening loop
while (true)
{
Console.Write("Waiting for a connection... ");
// Perform a blocking call to accept requests.
// You could also use server.AcceptSocket() here.
TcpClient client = server.AcceptTcpClient();
Console.WriteLine("Connected!");
// Get a stream object for reading and writing
NetworkStream stream = client.GetStream();
int i;
// Loop to receive all the data sent by the client.
i = stream.Read(bytes, 0, bytes.Length);
while (i != 0)
{
// Translate data bytes to a ASCII string.
data = System.Text.Encoding.ASCII.GetString(bytes, 0, i);
Console.WriteLine(String.Format("Received: {0}", data));
// Process the data sent by the client.
data = data.ToUpper();
byte[] msg = System.Text.Encoding.ASCII.GetBytes(data);
// Send back a response.
stream.Write(msg, 0, msg.Length);
Console.WriteLine(String.Format("Sent: {0}", data));
i = stream.Read(bytes, 0, bytes.Length);
}
// Shutdown and end connection
client.Close();
}
}
catch (SocketException e)
{
Console.WriteLine("SocketException: {0}", e);
}
Console.WriteLine("Hit enter to continue...");
Console.Read();
}
}
' The following sample is intended to demonstrate how to use a
' TcpListener for synchronous communcation with a TCP client
' It creates a TcpListener that connects to the specified port (13000).
' Any TCP client that wants to use this TcpListener has to explicitly connect
' to an address obtained by the combination of the server
' on which this TcpListener is running and the port 13000.
' This TcpListener simply echoes back the message sent by the client
' after translating it into uppercase.
' Refer to the related client in the TcpClient class.
'/
Imports System.IO
Imports System.Net
Imports System.Net.Sockets
Imports System.Text
_
Class MyTcpListener
Public Shared Sub Main()
Try
' Set the TcpListener on port 13000.
Dim port As Int32 = 13000
Dim server As New TcpListener(IPAddress.Any, port)
' Start listening for client requests.
server.Start()
' Buffer for reading data
Dim bytes(1024) As [Byte]
Dim data As [String] = Nothing
' Enter the listening loop.
While True
Console.Write("Waiting for a connection... ")
' Perform a blocking call to accept requests.
' You could also use server.AcceptSocket() here.
Dim client As TcpClient = server.AcceptTcpClient()
Console.WriteLine("Connected!")
data = Nothing
' Get a stream object for reading and writing
Dim stream As NetworkStream = client.GetStream()
Dim i As Int32
' Loop to receive all the data sent by the client.
i = stream.Read(bytes, 0, bytes.Length)
While (i <> 0)
' Translate data bytes to a ASCII string.
data = System.Text.Encoding.ASCII.GetString(bytes, 0, i)
Console.WriteLine([String].Format("Received: {0}", data))
' Process the data sent by the client.
data = data.ToUpper()
Dim msg As [Byte]() = System.Text.Encoding.ASCII.GetBytes(data)
' Send back a response.
stream.Write(msg, 0, msg.Length)
Console.WriteLine([String].Format("Sent: {0}", data))
i = stream.Read(bytes, 0, bytes.Length)
End While
' Shutdown and end connection
client.Close()
End While
Catch e As SocketException
Console.WriteLine("SocketException: {0}", e)
End Try
Console.WriteLine(ControlChars.Cr + "Hit enter to continue...")
Console.Read()
End Sub
End Class
Remarks
AcceptTcpClient is a blocking method that returns a TcpClient that you can use to send and receive data. Use the Pending method to determine if connection requests are available in the incoming connection queue if you want to avoid blocking.
Use the TcpClient.GetStream method to obtain the underlying NetworkStream of the returned TcpClient. The NetworkStream will provide you with methods for sending and receiving with the remote host. When you are through with the TcpClient, be sure to call its Close method. If you want greater flexibility than a TcpClient offers, consider using AcceptSocket.
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
See also
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