Android how to update value of ProgressBar?

Question

My activity have a ProgressBar. When start activity, I\'ll check value get from another place and update to ProgressBar. Here\'s my code:

final ProgressBar p         


        

Answer 1

You are running a while (progressBar.getProgress() < 100) in the UI thread (you use runOnUiThread) so UI thread will be blocked (and nothing painted) until this loop finish.

You can:

• Put the runOnUiThread inside the loop and, maybe, a sleep inside de runOnUiThread call. However, it is not the preferred kind of solution since you are using too much CPU to just look for a value change. The sleep approach it a bit ugly but solves the cpu problem. It would be something like::

  Thread t = new Thread() {
      public void run() {
      int oldProgress = 0;
  
      while (progressBar.getProgress() < 100) {
              ((Activity) ctx).runOnUiThread(new Runnable() {
                  public void run() {
                      int value = Downloader.progress.get(gameId+ "");
                      if (value != oldProgress) {
                          oldProgress = value;
                          progressBar.setProgress(value);
                          progressText.setText(value + " %");
                      }
                  }
              }
              Thread.sleep(500);
          }
      });
    }
  };
  

• Update the progress bar in an event way so you only call (in the UI thread) the update code when progress changes. It is the preferred way.