UDP – Restart Listener

[Anonymous]

Hello,

I have problem while using the UDPConnectionListener. If I StopListening() and want to StartListening() for the same IPEndPoint again, an unhandled exception occures. The exception says:

Additional information: A UDP connection already exists with info [UDP-D-U] 0.0.0.0:4001 -> 0.0.0.0:0

Init UDP Listener:

SendReceiveOptions optionsToUseForUDPInput = new SendReceiveOptions<NetworkCommsDotNet.DPSBase.NullSerializer>();
udpListener = new UDPConnectionListener(optionsToUseForUDPInput, ApplicationLayerProtocolStatus.Disabled, UDPOptions.None);
udpListener.AppendIncomingUnmanagedPacketHandler(handleIncomingUDPPackage);

Code for Button which Start Listener:

Connection.StartListening(udpListener, new System.Net.IPEndPoint(System.Net.IPAddress.Any, 4001));

Code for Button which Stops Listener:

Connection.StopListening(udpListener);

Until here, everything works fine. But if I click on the Start Button again, the exception mentioned above throws.

Funny fact: The following code works without problems (if you write the Start/Stop/Start in one button:

Connection.StartListening(udpListener, new System.Net.IPEndPoint(System.Net.IPAddress.Any, 4001));
Connection.StopListening(udpListener);
Connection.StartListening(udpListener, new System.Net.IPEndPoint(System.Net.IPAddress.Any, 4001));

Thanks for your help in advance.

[Anonymous]

Heya Patrick,

Are you call stop listening you may have to recreate the UDPListener instance. i.e. in your start listening button event create a new udplistener.

Kind regards,
Marc

[Anonymous]

Hi Marc,

thanks for your answer.

Unfortunately this doesn’t work.

I create a new UDPListener-Instance and call StartListening(…).

It throws the same exception:

NetworkCommsDotNet.ConnectionSetupException: A UDP connection already exists with info [UDP-D-U] 0.0.0.0:4001 -> 0.0.0.0:0

I tried several different approaches but can’t find a way to reopen a UDP Listener at the same port if it was closed before.

Can you please send me your code? I am sure you tested it already.

Thanks!

• This reply was modified 8 years, 6 months ago by .

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