Every time I want to make my fragment call it's onStart() or onResume(), I do the the next :
getFragmentManager().beginTransaction().replace(R.id.containero1, new Massenger_frag(conversationID)).addToBackStack(null).commit(); is this good for the performance, is there another way to tell the fragment the new information arrived, and it must refresh its UI.
You can keep a reference to a "Massenger_frag" object that was used when doing the fragment replacement. You can also define a method "refresh" in your "Massenger_frag" class and call it from that instance variable. onStart()/onResume() from your fragment would also call the same refresh method to avoid code duplication.
What you are currently doing is not fast and adds a significant overhead as the new fragment is constructed every time and the old one gets deallocated.
the solution is simple: I just use BroadCast sender and receiver, and send the information throw Activity A to Activity B, the Activity B in its onReceive() call a function that refresh its content!
