title: android best approach notifying one activity and another
body: <p>I just want to ask what is the best approach for me to solve the following problem. The situation is like.</p>
  
  <p>1.) I have ActivityA &amp; ActivityB.</p>
  
  <p>2.) The User process something (AsyncTask) in ActivityA, now while user is waiting, he went to ActivityB. </p>
  
  <p>3.) So while user is in ActivityB, the task was successful done in ActivityA. How would i notify ActivityB that the task was already
      done in ActivityA?</p>