如何自动实现ZoomOutPageTransformer？

Question

我想在自己的ZoomOutPageTransformer中实现viewpager。我可以自动更改view page，但看不到卡的变化，只有文字变化。卡似乎静止不动。只有当我触摸更改卡片时，缩放动作才会发生。但是我希望我的卡片自动缩小而不会碰触。

这是我正在使用的代码。 我在这里做错什么了吗？

我的主要活动包含以下内容：

viewPager = (ViewPager) findViewById(R.id.viewPager);
/*After setting the adapter use the timer */
final Handler handler = new Handler();

final Runnable Update = new Runnable() {
    public void run() {
        String[] imagesName = new String[6];
        imagesName[0] = ("Temperature & Day" + "\n" + "\r" + "0" + "'" + "c" + "\r" + "\r" + "Cloudy");
        imagesName[1] = ("Temperature" + "\n" + "\r" + BitwiseOperation.CabinTemp + "\r" + "'" + "c");
        imagesName[2] = ("Trip" + "\n" + "\r" + (trunc_lastvalueodometer - trunc_odometer) + "\r" + "\r" + "Kms");
        imagesName[3] = ("Range" + "\n" + "\r" + drive_voltage_percentage.expected_range + "\r" + "\r" + "Kms");
        imagesName[4] = ("OdoMeter" + "\n" + "\r" + trunc_odometer + "\r" + "\r" + "Kms");

        //Initializing the Adapter for images
        PagerAdapter adapter = new CustomAdapter(MainActivity.this, imageId, imagesName);
        viewPager.setAdapter(adapter);

        if (currentPage == NUM_PAGES - 1) {
            currentPage = 0;
        }
        viewPager.setCurrentItem(currentPage++, true);
        viewPager.setAnimationCacheEnabled(true);
        viewPager.setPageTransformer(true, new ZoomOutPageTransformer());
    }
};

timer = new Timer(); // This will create a new Thread
timer.schedule(new TimerTask() { // task to be scheduled
    @Override
    public void run() {
        handler.post(Update);
    }
}, DELAY_MS, PERIOD_MS);

我的CustomAdapter包含以下内容：

public class CustomAdapter extends PagerAdapter {
    private Activity activity;
    private Integer[] imagesArray;
    private String[] namesArray;
    private boolean animationEnabled=true;

    public CustomAdapter(Activity activity,Integer[] imagesArray,String[] namesArray) {
        this.activity = activity;
        this.imagesArray = imagesArray;
        this.namesArray = namesArray;
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        LayoutInflater inflater = ((Activity)activity).getLayoutInflater();
        View viewItem = inflater.inflate(R.layout.image_item, container, false);
        TextView textView1 = (TextView) viewItem.findViewById(R.id.textview);
        textView1.setText(namesArray[position]);
        ((ViewPager)container).addView(viewItem);
        return viewItem;
    }

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return imagesArray.length;
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        // TODO Auto-generated method stub
        return view == ((View)object);
    }

    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        // TODO Auto-generated method stub
        ((ViewPager) container).removeView((View) object);
    }

ZoomoutpageTransformer在这里：

public class ZoomOutPageTransformer implements ViewPager.PageTransformer {
    private static final float MIN_SCALE = 0.85f;
    private static final float MIN_ALPHA = 0.5f;

    public void transformPage(View view, float position) {
        int pageWidth = view.getWidth();
        int pageHeight = view.getHeight();

        if (position < -1) { // [-Infinity,-1)
            // This page is way off-screen to the left.
            view.setAlpha(0);
        } else if (position <= 1) { // [-1,1]
            // Modify the default slide transition to shrink the page as well
            float scaleFactor = Math.max(MIN_SCALE, 1 - Math.abs(position));
            float vertMargin = pageHeight * (1 - scaleFactor) / 2;
            float horzMargin = pageWidth * (1 - scaleFactor) / 2;
            if (position < 0) {
                view.setTranslationX(horzMargin - vertMargin / 2);
            } else {
                view.setTranslationX(-horzMargin + vertMargin / 2);
            }

            // Scale the page down (between MIN_SCALE and 1)
            view.setScaleX(scaleFactor);
            view.setScaleY(scaleFactor);

            // Fade the page relative to its size.
            view.setAlpha(MIN_ALPHA +
                (scaleFactor - MIN_SCALE) /
                (1 - MIN_SCALE) * (1 - MIN_ALPHA));

        } else { // (1,+Infinity]
            // This page is way off-screen to the right.
            view.setAlpha(0);
        }
    }
}