public void onCreate(Bundle savedInstanceState) {    final Animation animation = new AlphaAnimation(1, 0); // Change alpha from fully visible to invisible    animation.setDuration(500); // duration - half a second    animation.setInterpolator(new LinearInterpolator()); // do not alter animation rate    animation.setRepeatCount(Animation.INFINITE); // Repeat animation infinitely    animation.setRepeatMode(Animation.REVERSE); // Reverse animation at the end so the button will fade back in    final Button btn = (Button) findViewById(R.id.your_btn);    btn.startAnimation(animation);    btn.setOnClickListener(new OnClickListener() {        @Override        public void onClick(final View view) {            view.clearAnimation()        }    });}