Was this page helpful?
Your feedback about this content is important. Let us know what you think.
Additional feedback?
1500 characters remaining
Pending Method

TcpListener.Pending Method

Determines if there are pending connection requests.

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

public bool Pending()

Return Value

Type: System.Boolean
true if connections are pending; otherwise, false.


The listener has not been started with a call to Start.

This non-blocking method determines if there are any pending connection requests. Because the AcceptSocket and AcceptTcpClient methods block execution until the Start method has queued an incoming connection request, the Pending method can be used to determine if connections are available before attempting to accept them.

The following code example checks the Pending method. If a connection request is waiting to be accepted, then a call to the AcceptTcpClient method is made.

              // Use the Pending method to poll the underlying socket instance for client connection requests.
  				IPAddress ipAddress = Dns.Resolve("localhost").AddressList[0];
           	TcpListener tcpListener =  new TcpListener(ipAddress, portNumber); 
		    	if (!tcpListener.Pending()) {

		    	Console.WriteLine("Sorry, no connection requests have arrived");

                   //Accept the pending client connection and return a TcpClient object initialized for communication.
                   TcpClient tcpClient = tcpListener.AcceptTcpClient();
                   // Using the RemoteEndPoint property.
                   Console.WriteLine("I am listening for connections on " + 
                                               IPAddress.Parse(((IPEndPoint)tcpListener.LocalEndpoint).Address.ToString()) +
      	                                        "on port number " + ((IPEndPoint)tcpListener.LocalEndpoint).Port.ToString());

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1
© 2015 Microsoft