ViewPager的画廊效果间距问题

控件的布局

view的父控件一定要设置属性：

 android:clipChildren="false"

然后viewpager布局如下：

  <android.support.v4.view.ViewPager
        android:id="@+id/viewPager"
        android:clipChildren="false"
        android:layout_marginStart="20dp"
        android:layout_marginEnd="20dp"
        android:layout_width="match_parent"
        android:layout_height="160dp"/>

代码设置

       //设置适配器
                mViewPager.setPageMargin(-70);
                mViewPager.setPageTransformer(true, new ZoomOutPageTransformer());
                root.setOnTouchListener((view, motionEvent) -> mViewPager.dispatchTouchEvent(motionEvent));
                mViewPager.setOffscreenPageLimit(authorBreifModels.size());
                mViewPager.setAdapter(new MyAdapter(getContext(), authorBreifModels));
                mViewPager.setCurrentItem(1);

间距是通过xml中的控件margin跟代码mViewPger.setPageMargin一起控制的！setPageMargin设置负数！

动画效果代码：

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

    @Override
    @SuppressLint("NewApi")
    public void transformPage(View view, float position)
    {
        int pageWidth = view.getWidth();
        int pageHeight = view.getHeight();

        Log.e("TAG", view + " , " + position + "");

        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)
            {
                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);
        }
    }
}