viewPager动画切换效果

viewPager动画切换效果

ViewPager vp=null;
RelativeLayout rel_layout=null;

ArrayList<Fragment> fragments=null;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    fragments=new ArrayList<>();
    MyFragment myFragment1=MyFragment.getInstance(R.mipmap.bg_1);
    fragments.add(myFragment1);
    MyFragment myFragment2=MyFragment.getInstance(R.mipmap.bg_2);
    fragments.add(myFragment2);
    MyFragment myFragment3=MyFragment.getInstance(R.mipmap.bg_3);
    fragments.add(myFragment3);
    MyFragment myFragment4=MyFragment.getInstance(R.mipmap.bg_4);
    fragments.add(myFragment4);
    MyFragment myFragment5=MyFragment.getInstance(R.mipmap.bg_5);
    fragments.add(myFragment5);

    vp= (ViewPager) findViewById(R.id.vp);
    //一定要设置成数据源总个数
    vp.setOffscreenPageLimit(fragments.size());
    vp.setPageTransformer(true, new ScalePageTransformer());

    MyAdapter adapter=new MyAdapter(getSupportFragmentManager());
    vp.setAdapter(adapter);

    rel_layout= (RelativeLayout) findViewById(R.id.rel_layout);
    rel_layout.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            for (int i=0;i<vp.getChildCount();i++) {
                int[] location=new int[2];
                View view=vp.getChildAt(i);
                view.getLocationOnScreen(location);
                int minX=location[0];
                int maxX=minX+view.getWidth();
                int minY=view.getTop();
                int maxY=view.getBottom();

                int x= (int) event.getX();
                int y= (int) event.getY();

                Rect rect=new Rect(minX, minY, maxX, maxY);
                if (rect.contains(x, y)) {
                    vp.setCurrentItem(i);
                }
            }
            return false;
        }
    });
}

public class MyAdapter extends FragmentPagerAdapter {

    public MyAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        return fragments.get(position);
    }

    @Override
    public int getCount() {
        return fragments.size();
    }
}

private class ScalePageTransformer implements ViewPager.PageTransformer {
    @Override
    public void transformPage(View page, float position) {
        float max=1.2f;
        float min=0.6f;
        if (position<0) {
            page.setScaleX(max+(max-min)*position);
            page.setScaleY(max+(max-min)*position);
        }
        else if (position>0) {
            page.setScaleX(max-(max-min)*position);
            page.setScaleY(max-(max-min)*position);
        }
        else {
            page.setScaleX(max);
            page.setScaleY(max);
        }
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) {
            page.getParent().requestLayout();
        }
    }
}