yes you can achieve this.if you are opening one activity from another activity and updating some elements,and if you need to update that in your previous activity based on the result then open your intent for result..
Example will be
Intent abc = new Intent(A.this,B.class);
startActivityForResult(abc,123);
that will open your B.class..while that class completes its operation call
setResult(RESULT_OK);
and after that in your A.class
override this function
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// TODO Auto-generated method stub
//super.onActivityResult(requestCode, resultCode, data);
if(requestCode==123&& resultCode == RESULT_OK)
//do something...... /*This is the code for updating your A.class */
}