title: AlertDialog with DatePicker
body: <p>My idea is to use an AlertDialog and set to it a a DatePicker.<br>
  My code is:</p>
  
  <pre><code>    AlertDialog.Builder builder = new AlertDialog.Builder(this);
      DatePicker picker = new DatePicker(this);
      picker.setCalendarViewShown(false);
  
      builder.setTitle("Create Year");
      builder.setView(picker);
      builder.setNegativeButton("Cancel", null);
      builder.setPositiveButton("Set", null);
  
      builder.show();
  </code></pre>
  
  <p>it works, but my question is: how can i <strong>have the listeners on the set and cancel button</strong>?<br>
  About the set button i would like to have the listener and (of course) <strong>get the date of the user (his date selection)</strong><br><br>
  <br>
  I want also <strong>show just the year</strong> so i want to hide the day and month data.</p>