title: Opening dialog activity on creating another activity
body: <p>I've got an activity, call it A, that when initially opened I would like to programmatically open a another dialog theme activity, B, over the top.  The user would select some info from the dialog activity and return to activity A.  When resuming to activity A at some later point the data set would be available, so the dialog would not need to be shown.</p>
  
  <p>The problem is attempting to start the dialog activity from activity A's onResume or onCreate methods causes strange and undesirable behaviour.  The task appears to kind of freezes for a good few seconds and then the dialog is displayed correctly, but activity A isn't shown behind.</p>
  
  <p>Thanks
  Peter</p>