为默认recyclerView创建展开动画(将视图的可见性从to更改为visible)

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
    private List<Item> itemList;

    public MyAdapter(List<Item> itemList) {
        this.itemList = itemList;
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_layout, parent, false);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        Item item = itemList.get(position);
        holder.bind(item);
    }

    @Override
    public int getItemCount() {
        return itemList.size();
    }

    public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
        private TextView titleTextView;
        private TextView contentTextView;
        private boolean isExpanded;

        public ViewHolder(View itemView) {
            super(itemView);
            titleTextView = itemView.findViewById(R.id.titleTextView);
            contentTextView = itemView.findViewById(R.id.contentTextView);
            itemView.setOnClickListener(this);
        }

        public void bind(Item item) {
            titleTextView.setText(item.getTitle());
            if (isExpanded) {
                contentTextView.setVisibility(View.VISIBLE);
            } else {
                contentTextView.setVisibility(View.GONE);
            }
        }

        @Override
        public void onClick(View v) {
            isExpanded = !isExpanded;
            notifyItemChanged(getAdapterPosition());
        }
    }
}