title: How do I know the sending port number in QUdpSocket?
body: <p>Is there a way I can get the port number the udp socket used to send message?</p>
  
  <p>What I want to do is to send a udp datagram to someone and listen to that sending port.</p>
  
  <p>For example in the following code:</p>
  
  <pre><code>QUdpSocket *s = new QUdpSocket(this);
  s.writeDataGram(theData,theIp,thePort);
  </code></pre>
  
  <p>does it automaticly binds socket s with whatever the sending port is?</p>
  
  <p>If so, can I listen to that sending port?</p>