Painless threading in Android UI

Main or UI thread:

• in charge of dispatching the events to the appropriate widgets & drawing event.
• ANR happens if UI thread blocked for more than 5 secs.
• the Android UI toolkit is not thread-safe and must always be manipulated on the UI thread.

ways to access the UI thread from other threads

• Activity.runOnUiThread(Runnable)
• View.post(Runnable)
• View.postDelayed(Runnable, long)
• Handler

  These methods tend to make your code complicated. Android offers a new utility class, called AsyncTask, that simplifies the creation of long-running tasks that need to communicate with the user interface.