TcpListener Constructor (Int32)

Note: This API is now obsolete.

Initializes a new instance of the TcpListener class that listens on the specified port.

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

[ObsoleteAttribute("This method has been deprecated. Please use TcpListener(IPAddress localaddr, int port) instead.")]
public TcpListener(
	int port


Type: System.Int32

The port on which to listen for incoming connection attempts.


port is not between MinPort and MaxPort.

This constructor is obsolete. Use the TcpListener.TcpListener(IPAddress, Int32) or TcpListener.TcpListener(IPEndPoint) constructors.

This constructor allows you to specify the port number on which to listen for incoming connection attempts. With this constructor, the underlying service provider assigns the most appropriate network address. If you do not care which local port is used, you can specify 0 for the port number. In this case, the service provider will assign an available port number between 1024 and 5000. If you use this approach, you can discover what local network address and port number has been assigned by using the LocalEndpoint property.

Call the Start method to begin listening for incoming connection attempts.

The following code example creates a TcpListener using a local port number.

        //Creates an instance of the TcpListener class by providing a local port number.  
		IPAddress ipAddress = Dns.Resolve("localhost").AddressList[0];
            TcpListener tcpListener =  new TcpListener(ipAddress, 13);    
        catch ( Exception e ){
            Console.WriteLine( e.ToString());

.NET Framework

Supported in: 1.0
Obsolete (compiler warning) in 4.6
Obsolete (compiler warning) in 4.5
Obsolete (compiler warning) in 4.5.1
Obsolete (compiler warning) in 4.5.2
Obsolete (compiler warning) in 4
Obsolete (compiler warning) in 3.5
Obsolete (compiler warning) in 3.5 SP1
Obsolete (compiler warning) in 3.0
Obsolete (compiler warning) in 3.0 SP1
Obsolete (compiler warning) in 3.0 SP2
Obsolete (compiler warning) in 2.0
Obsolete (compiler warning) in 2.0 SP1
Obsolete (compiler warning) in 2.0 SP2
Obsolete (compiler warning) in 1.1

.NET Framework Client Profile

Obsolete (compiler warning) in 4
Obsolete (compiler warning) in 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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