Question

I’m searching for the easiest solution to implement a self updating digital clock in Android. I know that there is already digital clock class: http://developer.android.com/reference/android/widget/DigitalClock.html
and yes it’s also deprecated. From API 17 we now use TextClock. Anyways for the sake of learning i want to make my own custom clock showing hh:mm:ss and of course should updating itself.

So far i make reference to my textview ( where digital clock will be displayed ), and i got instance of Calendar class and i also sign minutes, hours and seconds to instance variables:

Calendar cal = Calendar.getInstance();
            hour = cal.get(Calendar.HOUR_OF_DAY);
            min = cal.get(Calendar.MINUTE);
            sec = cal.get(Calendar.SECOND);
                clock.setText(hour+":"+min+":"+sec);

If i run this code, the accurate time is displayed on emulator but obviously it’s not updating. What i must do, so my code will “looping” and updating my clock?

I already checked this nice answer: Android: How do I display an updating clock in a TextView but my question is: I want the easiest solution of digital clock in android =) Do i still need to use Handler?

Answer 1

Well using a Handler isn’t that difficult. One possible implementation is (note: I didn’t check if it leaks or not):

final Handler h = new Handler();
h.post(new Runnable() {
    @Override
    public void run() {
        updateTime();
        h.postDelayed(this, 1000);
    }
});

If you don’t want to use Handler, you could also use a CountDownTimer with millisInFuture set to Long.MAX_VALUE. But this is really a hack and I don’t know if Android implementation can handle the integer overflow correctly.