Recyclerview初始动画

Question

There is a common recyclerview animation I see in some apps. When recyclerview is populated for the first time , its items slide in from bottom while also fading in at the same time. How to achieve this ?

Answer 1

setItemAnimator() is used for item changes/ new insertion/ deletion. It will not work at first time, if you are using setAdapter() with items.

Try this inside the Recycler view adapter:

int lastPosition = -1;
@Override 
public void onViewAttachedToWindow(final ViewHolder holder) {
            super.onViewAttachedToWindow(holder);
            final long delayTime = 200;
            holder.card.setVisibility(View.INVISIBLE);

            if (holder.getPosition() > lastPosition) {
                holder.card.getHandler().postDelayed(new Runnable() {
                    @Override 
                    public void run() { 
                        holder.card.setVisibility(View.VISIBLE);
                        ObjectAnimator alpha = ObjectAnimator.ofFloat(holder.card, "alpha", 0f, 1f);
                        ObjectAnimator scaleY = ObjectAnimator.ofFloat(holder.card, "scaleY", 0f, 1f);
                        ObjectAnimator scaleX = ObjectAnimator.ofFloat(holder.card, "scaleX", 0f, 1f);
                        AnimatorSet animSet = new AnimatorSet();
                        animSet.play(alpha).with(scaleY).with(scaleX);
                        animSet.setInterpolator(new OvershootInterpolator());
                        animSet.setDuration(400);
                        animSet.start();

                    } 
                }, delayTime);

                lastPosition = holder.getPosition();
            } else { 
                holder.card.setVisibility(View.VISIBLE);
            } 
        } 

You can change the AnimatorSet and Interpolator as your need.

Like:

PropertyValuesHolder translateX = PropertyValuesHolder.ofFloat(View.TRANSLATION_X, 0, 0);
                    PropertyValuesHolder translateY = PropertyValuesHolder.ofFloat(View.TRANSLATION_Y, 100, 0);
                    ObjectAnimator animator = ObjectAnimator.ofPropertyValuesHolder(holder.itemView, translateX, translateY);
                    AnimatorSet animSet = new AnimatorSet();
                    animSet.play(animator);
                    animSet.setInterpolator(new AccelerateDecelerateInterpolator());
                    animSet.setDuration(400);
                    animSet.start();

Answer 2

Try this way to animate recycerview

RecyclerView.ItemAnimator itemAnimator = new DefaultItemAnimator();
itemAnimator.setAddDuration(1000);
itemAnimator.setRemoveDuration(1000);
recyclerView.setItemAnimator(itemAnimator);

https://www.sitepoint.com/mastering-complex-lists-with-the-android-recyclerview/

http://www.birbit.com/recyclerview-animations-part-1-how-animations-work/

https://www.studytutorial.in/android-recyclerview-with-animation-tutorial

https://github.com/gabrielemariotti/RecyclerViewItemAnimators

https://github.com/couchbaselabs/mini-hacks/tree/master/android-recycler-view-animations