android - RecyclerView - Activity 开始时的 SlideIn 动画

Question

如何在我的回收站 View 项目上一个接一个地添加动画幻灯片。就像 Activity 开始一样，回收器 View 的列表项一项一项地滑入。我正在使用 LinearLayoutManager

并非所有内容都应同时滑入。甚至在滚动时也不应如此。就在创建 Activity 时。

我搜索了但没有找到任何东西。

我想实现这样的目标:https://youtu.be/Q8TXgCzxEnw?t=30s

Answer 1

我在几个月前制作了一个示例应用程序，它在重新排列期间有一个连续的滑入滑出动画。提供演示视频 here .它应该会给您一些想法。

最相关类文件的链接是 here ，我将复制下面的代码。

public class AllNotesFragmentRecyclerView extends RecyclerView {

    private static final int BASE_ANIMATION_TIME = 50;
    private static final int MAX_ANIMATION_TIME_INCREMENT = 100;

    private int screenWidth;
    private int startX, finalX;

    private int[] interpolatedAnimationTimes;

    public AllNotesFragmentRecyclerView(Context context) {
        super(context);
        init(context);
    }

    public AllNotesFragmentRecyclerView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context);
    }

    public AllNotesFragmentRecyclerView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init(context);
    }

    private void init(Context context) {
        calculateScreenWidth(context);

        startX = 0;
        finalX = -(screenWidth);
    }

    private void calculateScreenWidth(Context context) {
        WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
        DisplayMetrics metrics = new DisplayMetrics();
        wm.getDefaultDisplay().getMetrics(metrics);
        screenWidth = metrics.widthPixels;
    }

    private int calculateInterpolatedAnimationTime(int currentIndex, int maxIndex) {
        float percentage = ((float)currentIndex/(float)maxIndex);
        float increment = (float) MAX_ANIMATION_TIME_INCREMENT * percentage;
        return (int) (BASE_ANIMATION_TIME + increment);
    }

    public void updateListOrder() {
        createAnimatorSet();
    }

    private void createAnimatorSet() {

        AnimatorSet set = new AnimatorSet();
        ArrayList<Animator> animArrayList = new ArrayList<>();

        for (int i = 0; i < getChildCount(); i++) {
            ObjectAnimator anim = ObjectAnimator
                    .ofFloat(getChildAt(i), "translationX", finalX);

            int duration = calculateInterpolatedAnimationTime(i, getChildCount());

            anim.setDuration(duration);
            anim.addListener(new RowAnimationListener(i, duration, startX));
            animArrayList.add(anim);
        }
        set.setInterpolator(new AccelerateInterpolator());
        set.playSequentially(animArrayList);
        set.start();
    }

    private void animateOn(int childPosition, int duration, int targetValue) {
        ObjectAnimator animator = ObjectAnimator
                .ofFloat(getChildAt(childPosition), "translationX", targetValue);
        animator.setInterpolator(new DecelerateInterpolator());
        animator.setDuration(duration);
        animator.start();
    }
//...

    private class RowAnimationListener implements Animator.AnimatorListener {

        private int position, duration, targetX;

        public RowAnimationListener(int position, int duration, int targetX) {
            this.position = position;
            this.duration = duration;
            this.targetX = targetX;
        }

        @Override
        public void onAnimationStart(Animator animation) {
        }

        @Override
        public void onAnimationEnd(Animator animation) {
            int currentItem = getLinearLayoutManager().findFirstVisibleItemPosition() + position;
            getAdapter().notifyItemChanged(currentItem);
            notifyRowsPeripheralToVisibleItemsDataChanged(position);
            animateOn(position, duration, targetX);
        }

        @Override
        public void onAnimationCancel(Animator animation) { }

        @Override
        public void onAnimationRepeat(Animator animation) { }
    }
}