Image flashing at random coordinates - Android

Hi guys i am new in android and i want a little help in my university exercise :) I want create a mini-game where an image(robot) appear and disapear at random positions and i have to shoot it until i quit. I have the random coordinate but i dont know how to do the flashing. When i start the app do 1 and then stand in the screen at 1 position

public class JatekTer extends AppCompatActivity {


ImageView robot;
ImageView explosion;

AnimationDrawable andrw;
Bitmap bmap;

int delay_ms = 1000;



@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
    setContentView(R.layout.activity_jatek_ter);

    robot = (ImageView) findViewById(R.id.robotimage);



    robot.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            robot.setImageResource(R.drawable.explosionrobot);

        }
    });

    Handler hand = new Handler();
    hand.postDelayed(new Runnable() {
        @Override
        public void run() {

                Flashing();


        }
    }, delay_ms);

}



public void Flashing(){


        AbsoluteLayout.LayoutParams absParams =
                (AbsoluteLayout.LayoutParams) robot.getLayoutParams();

        DisplayMetrics displaymetrics = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
        int width = displaymetrics.widthPixels-150;
        int height = displaymetrics.heightPixels-150;


        Random r = new Random();


        absParams.x = r.nextInt(width);
        absParams.y = r.nextInt(height);
        robot.setLayoutParams(absParams);


        robot.setVisibility(View.VISIBLE);


}

}