When to use handler.post() & when to new Thread()

by

You should use Handler.post() whenever you want to do operations on the UI thread.

So let’s say you want to change a TextView‘s text in the callback. Because the callback is not running on the UI thread, you should use Handler.post().

In Android, as in many other UI frameworks, UI elements (widgets) can be only modified from UI thread.

Also note that the terms “UI thread” and “main thread” are often used interchangeably.

Edit: an example of the long-running task:

mHandler = new Handler();

new Thread(new Runnable() {
  @Override
  public void run () {
    // Perform long-running task here
    // (like audio buffering).
    // You may want to update a progress
    // bar every second, so use a handler:
    mHandler.post(new Runnable() {
     @Override
     public void run () {
       // make operation on the UI - for example
       // on a progress bar.
     }
    });
  }
}).start();

Of course, if the task you want to perform is really long and there is a risk that user might switch to some another app in the meantime, you should consider using a Service.

More Related Contents:

  1. How to use Handler in AsynkTask in android
  2. Repeat a task with a time delay?
  3. Handler vs AsyncTask vs Thread [closed]
  4. Best use of HandlerThread over other similar classes
  5. This Handler class should be static or leaks might occur: IncomingHandler
  6. Example communicating with HandlerThread
  7. Android: When should I use a Handler() and when should I use a Thread?
  8. How to use postDelayed() correctly in Android Studio?
  9. Handlers, MessageQueue, Looper, do they all run on the UI thread?
  10. Stop handler.postDelayed()
  11. How to update ui from asynctask
  12. cancelling a handler.postdelayed process
  13. How to add manifest permission to an application?
  14. Using ZXing to create an Android barcode scanning app [duplicate]
  15. Activity OnDestroy never called?
  16. Is it possible to disable scrolling on a ViewPager
  17. Schedule a work on a specific time with WorkManager
  18. How to use a custom typeface in a widget?
  19. Image on canvas to JPEG file
  20. TextWatcher for more than one EditText
  21. “Unparseable date: 1302828677828” trying to deserialize with Gson a millisecond-format date received from server
  22. An Android app remembers its data after uninstall and reinstall
  23. Only one log in per user at the time in Firebase for android
  24. Is there a simple example of the PopupWindow class using Android v2.0?
  25. java.lang.NumberFormatException: Invalid int: “” in android
  26. Reading EXIF data from byte array in android
  27. How to solve GC_concurrent freed? [closed]
  28. Need Help in Downloading in Background Images in Android?
  29. android circular gallery?
  30. How to remove white underline in a SearchView widget in Toolbar Android

Leave a Comment