CountDownTimer is useful for repeatedly performing an action in a steady interval for a set duration. In this example, we will update a text view every second for 30 seconds telling how much time is remaining. Then when the timer finishes, we will set the TextView to say "Done."
TextView textView = (TextView)findViewById(R.id.text_view);
CountDownTimer countDownTimer = new CountDownTimer(30000, 1000) {
public void onTick(long millisUntilFinished) {
textView.setText(String.format(Locale.getDefault(), "%d sec.", millisUntilFinished / 1000L));
}
public void onFinish() {
textView.setText("Done.");
}
}.start();