title: Using startActivityForResult, how to get requestCode in child activity?
body: <p>I have four activities, say A, B, C and D.
  My situation is A will start the activity B by startActivityForResult.  </p>
  
  <pre><code>startActivityForResult(new Intent(this,B.class),ONE);
  </code></pre>
  
  <p>In other situation i will B with other situation. like </p>
  
  <pre><code> startActivityForResult(new Intent(this,B.class),TWO);
  </code></pre>
  
  <p>In B, I need to call C or D depending on requestCode. I.e if ONE need to start C else D.<br>
  So I need to know how to check the requestCode in the child Activity (B here).<br>
  In other words, I want to get the request code that Activity B was started with.   </p>