•Sending a Message or Runnable objects from Main Thread
to Background Thread
Generally Background thread does not have its own message queue ..so we create looper instance for that
background thread which maintains messagequeue then we create instance of Handler within run() of
background thread and that handler instance implicitly gets associated with thread that is creating it.
Now that created handler instance is associated with looper instance.
If we want to send message from Main thread to Background Thread
1. We first take reference of handler of background thread.
2. And then we give message to handler which will post message to messagqueue of that
background thread
3. In order to complete above 2 steps ..You must need to create looper for background thread which
is responsible for maintaining a messagequeue for that background thread.
