TextView.setText() crashing my app

Question

I'm just learning Android and I'm already having trouble with complete basics:

I'd like to have a timer that increments a TextView but it crashes the first time the timer ticks.

Here's my code:

public class Game extends Activity {

Timer timer = new Timer();
int i = 0;
TextView text;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_game);

    text = (TextView) findViewById(R.id.timerText); 
    text.setText("0");

    timer.schedule(new TimerTask() {
        public void run() {
            i++;
            System.out.println(i);
            text.setText(i + "");
            if(i>100) timer.cancel();
        }
    }, 1000, 1000);
}
}

Here's my XML:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >

...

<TextView
    android:id="@+id/timerText"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="50dp"
    android:text="Large Text"
    android:textAppearance="?android:attr/textAppearanceLarge" />
</RelativeLayout>

I found a ton of solutions for setText crashing but none of them seemed to fix this.

Just in the post. I was having trouble with code tags. Thanks — franga2000, Jun 08 '14 at 19:12
You should add stack trace from LogCat into your question - but it's quite likely related to Timer not running in UI thread. — harism, Jun 08 '14 at 19:15

score 0 · Answer 1 · edited May 23 '17 at 12:20

0

Look at this : Android: Accessing UI Element from timer thread

Explantation : you've got error because you try accessing to UI element(in your case - textView) from separate background thread.

Also look this answer with simplifiest example: https://stackoverflow.com/a/6702767/2956344

edited May 23 '17 at 12:20

Community

1
1

answered Jun 08 '14 at 19:15

Sergey Shustikov

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score 0 · Answer 2 · edited May 23 '17 at 12:05

0

if you are accesing to UI element in the timer run you should use a Handler or runOnUITheard.

Please check:

http://developer.android.com/reference/android/app/Activity.html#runOnUiThread(java.lang.Runnable)

and

Android: Accessing UI Element from timer thread

edited May 23 '17 at 12:05

Community

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1

answered Jun 08 '14 at 19:15

fpanizza

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score 0 · Accepted Answer · answered Jun 08 '14 at 19:16

0

You need to call text.setText(i + ""); from runOnUiThread()

answered Jun 08 '14 at 19:16

CodeWarrior

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TextView.setText() crashing my app

3 Answers3