Question

I am trying to get a basic timer to work on Android and I have the following code in the onCreate() method:

    editText = (EditText) findViewById(R.id.edit_message);
    Timer time = new Timer();     

    time.schedule(new TimerTask() {
        public void run() {
            timesince++;
            editText.setText("Timeran:"+timesince);
            Log.d("TIMER", "TimerTask run");
        }}, 0, 1000);

So hopefully it would update the textbox with a increasing value (timesince) -which is declared at top of program, along with editText…

However, (although I get no compile issues) when I run it on the emulator it does not work at all. App says ‘blahblahblah has stopped working…’

Am I doing Timers wrong? What am I missing?

Thanks alot.

(P.S. App works fine if this code is removed so I know there is an issue with this section.)

EDIT: I believe this is my logcat output, sorry for wall of text:

10-11 03:40:49.260: E/AndroidRuntime(561): FATAL EXCEPTION: Timer-0
10-11 03:40:49.260: E/AndroidRuntime(561): android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
10-11 03:40:49.260: E/AndroidRuntime(561):  at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:3939)
10-11 03:40:49.260: E/AndroidRuntime(561):  at android.view.ViewRootImpl.invalidateChild(ViewRootImpl.java:714)
10-11 03:40:49.260: E/AndroidRuntime(561):  at android.view.ViewRootImpl.invalidateChildInParent(ViewRootImpl.java:763)
10-11 03:40:49.260: E/AndroidRuntime(561):  at android.view.ViewGroup.invalidateChild(ViewGroup.java:4012)
10-11 03:40:49.260: E/AndroidRuntime(561):  at android.view.View.invalidate(View.java:8454)
10-11 03:40:49.260: E/AndroidRuntime(561):  at android.widget.TextView.invalidateCursor(TextView.java:4319)
10-11 03:40:49.260: E/AndroidRuntime(561):  at android.widget.TextView.spanChange(TextView.java:7670)
10-11 03:40:49.260: E/AndroidRuntime(561):  at android.widget.TextView$ChangeWatcher.onSpanAdded(TextView.java:8020)
10-11 03:40:49.260: E/AndroidRuntime(561):  at android.text.SpannableStringBuilder.sendSpanAdded(SpannableStringBuilder.java:898)
10-11 03:40:49.260: E/AndroidRuntime(561):  at android.text.SpannableStringBuilder.setSpan(SpannableStringBuilder.java:614)
10-11 03:40:49.260: E/AndroidRuntime(561):  at android.text.SpannableStringBuilder.setSpan(SpannableStringBuilder.java:520)
10-11 03:40:49.260: E/AndroidRuntime(561):  at android.text.Selection.setSelection(Selection.java:76)
10-11 03:40:49.260: E/AndroidRuntime(561):  at android.text.Selection.setSelection(Selection.java:87)
10-11 03:40:49.260: E/AndroidRuntime(561):  at android.text.method.ArrowKeyMovementMethod.initialize(ArrowKeyMovementMethod.java:302)
10-11 03:40:49.260: E/AndroidRuntime(561):  at android.widget.TextView.setText(TextView.java:3244)
10-11 03:40:49.260: E/AndroidRuntime(561):  at android.widget.TextView.setText(TextView.java:3110)
10-11 03:40:49.260: E/AndroidRuntime(561):  at android.widget.EditText.setText(EditText.java:78)
10-11 03:40:49.260: E/AndroidRuntime(561):  at android.widget.TextView.setText(TextView.java:3085)
10-11 03:40:49.260: E/AndroidRuntime(561):  at com.example.cultivation.MainActivity$1.run(MainActivity.java:54)
10-11 03:40:49.260: E/AndroidRuntime(561):  at java.util.Timer$TimerImpl.run(Timer.java:284)

Answer 1

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

This is the problem

You have to move the portion of the background task that updates the ui onto the main thread or create the mHandler in your UI thread;

Update:

Updating the UI from a Timer : http://android-developers.blogspot.com/2007/11/stitch-in-time.html