如何在android中的位图中设置计时器

Question

This is my code and im trying to add animation to my background using bitmap..!!im able to animate everything but the problem is i dont know how to start a particular image after certain time..All the bitmap images (heartfal,heartfal1,heartfal2,heartfal3)are starting at the same time.I need to set timer for certain bmp images so tat i can start a few seconds later than other images.And also all the bmp images are starting from the top..!! I need few images to start somewhere>I dont know to change the height>If i give "40" (say)in place of "changing y" im able to change the position but bmp image is not moving ..Its satnding still in the same"40" position..Iam new to android plz help..!!Thanks in advance

public class Mybringback extends View {
        Bitmap heartsfal;
        Bitmap heartsfal2;
        Bitmap heartsfal3;
        Bitmap heartsfal4;
        float changingY;

        public Mybringback(Context context, AttributeSet attrs) {
            super(context);

            heartsfal = BitmapFactory.decodeResource(getResources(),
                    R.drawable.animation1);
            heartsfal2 = BitmapFactory.decodeResource(getResources(),
                    R.drawable.animation2);
            heartsfal3 = BitmapFactory.decodeResource(getResources(),
                    R.drawable.animation3);
            heartsfal4 = BitmapFactory.decodeResource(getResources(),
                    R.drawable.animation4);
            changingY = 0;

        }

        @Override
        protected void onDraw(Canvas canvas) {
            super.onDraw(canvas);

            canvas.drawBitmap(heartsfal, 20, changingY, null);
            if (changingY < canvas.getHeight()) {
                changingY += 1;
            } else {
                changingY = 0;
            }
            canvas.drawBitmap(heartsfal2, 120, changingY, null);
            if (changingY < canvas.getHeight()) {
                changingY += 1;
            } else {
                changingY = 0;
            }
            canvas.drawBitmap(heartsfal3, 260, changingY, null);
            if (changingY < canvas.getHeight()) {
                changingY += 1;
            } else {
                changingY = 0;
            }
            canvas.drawBitmap(heartsfal4, 400, changingY, null);
            if (changingY < canvas.getHeight()) {
                changingY += 1;
            } else {
                changingY = 0;
            }

            invalidate();
        }
    }

Answer 1

private ScheduledThreadPoolExecutor execAds = null;

private void startCheckTimer() {
        execAds = new ScheduledThreadPoolExecutor(1);       
        execAds.scheduleAtFixedRate(new MyTaskAds(), 0, 10, TimeUnit.MILLISECONDS);
    }

private class MyTaskAds implements Runnable {

        @Override
        public void run() {
            changingY += 1;
            invalidate();
        }
    }

Call startCheckTimer(), changingY will moving.... (Change time delay if you want.)