Android:像 Inshorts news app 这样的布局动画

Question

像那些新闻应用程序一样上下滑动效果 inshorts、远足新闻、杂音。

整个布局顺畅地向上/向下。
检查此链接上的应用程序 inshorts和 murmur .

我试过这段代码...

    public class VerticalViewPager extends ViewPager {
    public VerticalViewPager(Context context) {
        super(context);
        init();
    }

    public VerticalViewPager(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }
    private void init() {
        // The majority of the magic happens here
        setPageTransformer(true, new VerticalPageTransformer());
        // The easiest way to get rid of the overscroll drawing that happens on the left and right
        setOverScrollMode(OVER_SCROLL_NEVER);
    }
    private class VerticalPageTransformer implements PageTransformer {

        @SuppressLint("NewApi")
        @Override
        public void transformPage(View view, float position) {

            if (position < -1) { // [-Infinity,-1)
                // This page is way off-screen to the left.
                view.setAlpha(0);

            } else if (position <= 1) { // [-1,1]
                view.setAlpha(1);

                // Counteract the default slide transition
                view.setTranslationX(view.getWidth() * -position);

                //set Y position to swipe in from top
                float yPosition = position * view.getHeight();
                view.setTranslationY(yPosition);

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

    /**
     * Swaps the X and Y coordinates of your touch event.
     */
    private MotionEvent swapXY(MotionEvent ev) {
        float width = getWidth();
        float height = getHeight();

        float newX = (ev.getY() / height) * width;
        float newY = (ev.getX() / width) * height;

        ev.setLocation(newX, newY);

        return ev;
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev){
        boolean intercepted = super.onInterceptTouchEvent(swapXY(ev));
        swapXY(ev); // return touch coordinates to original reference frame for any child views
        return intercepted;
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        return super.onTouchEvent(swapXY(ev));
    }

}

在 MainActivity.java 中

VerticalViewPager Pager2;
PagerAdapter adapter;
String[] articleTitle;
String[] articleName;
String[] articleDiscription;

OnCreate()

Pager2=(VerticalViewPager)findViewById(R.id.pager);


// Pass results to ViewPagerAdapter Class
adapter = new ViewPagerAdapter(getActivity(), articleTitle, articleName,     articleDiscription, btnBack,articleImage);

// Binds the Adapter to the ViewPager
Pager2.setAdapter(adapter);

activity_main.xml

<com.example.flipnews.VerticalViewPager
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:id="@+id/pager"
   />

在我的代码中完成了简单的上下滑动，就像这样link . 但我想像上面提到的应用程序一样创建更好的动画效果。 或手机内置的照片库效果。

提前致谢。

Answer 1

经过多次研究，我找到了解决方案，希望对其他人有帮助。

提示:将 View 分页器背景颜色设置为黑色以获得更好的滑动效果。

 private static class VerticalPageTransformer implements PageTransformer {
        private static float MIN_SCALE = 0.75f;

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

            if (position < -1) { // [-Infinity,-1)
                // This page is way off-screen to the left.
                view.setAlpha(0);



            } else if (position <= 0) { // [-1,0]
                // Use the default slide transition when moving to the left page
                view.setAlpha(1);
                //view.setTranslationX(1);
                view.setScaleX(1);
                view.setScaleY(1);
                float yPosition = position * view.getHeight();
                view.setTranslationY(yPosition);
                view.setTranslationX(-1 * view.getWidth() * position);

            } else if (position <= 1) { // (0,1]
                // Fade the page out.
                view.setAlpha(1 - position);

                view.setTranslationX(-1 * view.getWidth() * position);

                // Scale the page down (between MIN_SCALE and 1)
               float scaleFactor = MIN_SCALE
                        + (1 - MIN_SCALE) * (1 - Math.abs(position));
                view.setScaleX(scaleFactor);
                view.setScaleY(scaleFactor);

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

        }
    }

    private MotionEvent swapXY(MotionEvent ev) {
        float width = getWidth();
        float height = getHeight();

        float newX = (ev.getY() / height) * width;
        float newY = (ev.getX() / width) * height;

        ev.setLocation(newX, newY);

        return ev;
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev){
        boolean intercepted = super.onInterceptTouchEvent(swapXY(ev));
        swapXY(ev); // return touch coordinates to original reference frame for any child views
        return intercepted;
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        return super.onTouchEvent(swapXY(ev));
    }

}