ViewPager水平缩放滑动图片效果

xml：

<android.support.v4.view.ViewPager
        android:id="@+id/vp_guide"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

使用：

ViewPager mViewPager = (ViewPager) findViewById(R.id.vp_guide);
mViewPager.setOffscreenPageLimit(4-1);//缓存，根据需求自定义
mViewPager.setPageMargin(-200);//处理两边碎片显示
mViewPager.setPageTransformer(true, new ZoomOutPageTransformer());
mViewPager.setAdapter(new FragmentPagerAdapter(getSupportFragmentManager()) {
    @Override
    public int getCount() {
        return 4;
    }

    @Override
    public Fragment getItem(int position) {
        return new PageFragment();
    }
});

关键api：

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

    /**
     * 当ViewPager滑动时，每一个界面都会回掉该方法，并且该方法跟随滑动不断回调
     * 参数：
     * view：当前停留显示的页面（注意：下面的循环不要直接用该view，因为该view会被自动加上一层FrameLayout布局）
     * position：当前页面滑动的位置，以当前页面的左侧边为0，两边终点分别为-1和1
     */
    @SuppressLint("NewApi")
    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) // a页滑动至b页 ； a页从 0.0 -1 ；b页从1 ~ 0.0
        { // [-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) {
                //api版本>=11，view相对原始位置的偏移量，不影响view属性
                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);
        }
    }
}

碎片：

public class PageFragment extends Fragment {
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_page, null);
        return view;
    }
}

碎片fragment_page.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:orientation="vertical">

    <ImageView
        android:src="@mipmap/page_icon"
        android:layout_width="250dp"
        android:layout_height="250dp" />

</LinearLayout>

补充：page_icon替换成自己的图片