Question

I’m trying to understand how to use a timer.

In my MainActivity.class, inside on create method, i have this code

  Timer  timer = new Timer();
  TimerTask updateM = new GestioneSlide();
  timer.scheduleAtFixedRate(updateM , 1000, 5000); // i want to do a thing every second   for 5 seconds

then i have another class where i override the method run, and where i want to write something in a texview that is in my MainActivity.class

class GestioneSlide extends TimerTask {


        @Override
       public void run() {
            MainActivity.TextViewName.setText("bla  bla");
            }

    }

My app crash, if i delete the MainActivity.TextViewName.setText("bla bla"); i have no problem. Probably i can’t write in that textview that way
What did i do wrong?

Answer 1

The timer does not fire its actions in GUI thread. Use runOnUiThread to switch into it. Assuming GestioneSlide is the inner class of your Activity, write

   class GestioneSlide extends TimerTask {

   public void run() {
     runOnUiThread(new Runnable() {
        public void run() {
           MainActivity.TextViewName.setText("bla  bla");
        }
     }
   }