Home/ Questions/Q 8104367
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-06-05T23:49:11+00:00

I was trying to do something else but kept on removing code thinking that

  • 0

I was trying to do something else but kept on removing code thinking that simplifying things will help in identifying my mistake. This is what I am left with (after a lot of simplification) and still I am not getting it why it is not doing it is supposed to! 

public class MyOwnTimerActivity extends Activity {

    int timeLeft = 5;
    TextView timerTextView;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Button timerButton = (Button) findViewById(R.id.button1);
        timerTextView = (TextView) findViewById(R.id.timerText);

        Thread timer = new Thread() {
            public void run() {
                try {
                    sleep(3000);
                } 
                catch (InterruptedException e) {
                    e.printStackTrace();
                }
                finally{
                    timerTextView.setText("something");
                }
            }
        };
        timer.start();
    }
}

Error: The application crashed after 3 seconds i.e. after timer goes off.

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    Ah, yes)) This is because you try to modify UI from non UI-thread

    Update:

    There are several ways to modify UI from another thread:

  2. Using Handler class with overriding handleMessage() method
  3. Using Activity class with calling runOnUI() method, passing there Runnable object in which run() method you modify UI
  4. Using View.post() or View.postDelayed() methods

    5. The last variant is the most convenient in your case. Modify your code in such manner:

    @Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    Button timerButton = (Button) findViewById(R.id.button1);
    timerTextView = (TextView) findViewById(R.id.timerText);
    timerTextView.postDelayed(
        new Runnable() {
           @Override
           run() {
               timerTextView.setText("something");
           }
        }, 3000);
}
  • 0