app crashing with "Called From Wrong Thread Exception"

android handler timertask
jeet.chanchawat picture jeet.chanchawat · Jun 16, 2012 · Viewed 11.9k times · Source

I added this part of the code in my onCreate() method and it crashes my app. need help.

LOGCAT:

android.view.ViewRoot$CalledFromWrongThreadException: Only the original thread 
that created a view hierarchy can touch its views.

CODE:

final TextView timerDisplayPanel = (TextView) findViewById(R.id.textView2);

    Timer t = new Timer();
    t.schedule(new TimerTask(){
        public void run(){
            timerInt++;
            Log.d("timer", "timer");
            timerDisplayPanel.setText("Time ="+ timerInt +"Sec");
        }
    },10, 1000);

Answer

Samir Mangroliya picture Samir Mangroliya · Jun 16, 2012 
Only the UI thread that created a view hierarchy can touch its views.

You are trying to change the text of the UI element in Non UI Thread, so it gives exception.Use runOnUiThread

 Timer t = new Timer();
 t.schedule(new TimerTask() {
 public void run() {
        timerInt++;
        Log.d("timer", "timer");

        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                timerDisplayPanel.setText("Time =" + timerInt + "Sec");
            }
        });

    }
}, 10, 1000);

Related questions

Timertask or Handler

Let's say that I want to perform some action every 10 seconds and it doesn't necessarily need to update the view. The question is: is it better (I mean more efficient and effective) to use timer with timertask like here: final …

Read More
TimerTask vs Thread.sleep vs Handler postDelayed - most accurate to call function every N milliseconds?

What is the most accurate way to call a function every N milliseconds? Thread with Thread.sleep TimerTask Handler with postDelayed I modified this example using Thread.sleep and it's not very accurate. I'm developing a music app that will …

Read More
Where do I create and use ScheduledThreadPoolExecutor, TimerTask, or Handler?

I need to make my RSS Feed reader check the feed every 10 minutes for new posts, and then parse them if there are new ones. I also need to update the UI about every minute. I have read and heard …

Read More