android - How can I make a button flash?

ron picture ron · Jan 31, 2011 · Viewed 43k times · Source

Is there any way, in code, to make a button flash continually and then stop flashing when pressed?

Answer

Alex Orlov picture Alex Orlov · Jan 31, 2011

There are several, depending on what kind of flashing you mean. You can, for example, use alpha animation and start it as your button first appears. And when the user clicks button, in your OnClickListener just do clearAnimation().

Example:

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();
        }
    });
}