在 RecyclerView 中展开和折叠卡片

Question

i'm working on a RecyclerView in Android which should contains expandable cards. I've already seen some questions like this or this but I can't figure out how to manage some things.

In my app (pic below) the expandable part is the one with the "maps" icon and "plus" icon.

Card expansion

During Google I/O 2016, Nick Butcher explained some of his code but i can't solve the part in which he divides the layout in two parts (the one that is always visibile itemView , and the expandable one, details ) in the onBindViewHolder method.

final boolean isExpanded = position==mExpandedPosition;
holder.details.setVisibility(isExpanded?View.VISIBLE:View.GONE);
holder.itemView.setActivated(isExpanded);
holder.itemView.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        mExpandedPosition = isExpanded ? -1:position;
        TransitionManager.beginDelayedTransition(recyclerView);
        notifyDataSetChanged();
    }
});

Can anyone explain me this and the other parts that make the animation and the expansion possible? You could find useful the Heisenberg's reply in this question Thanks!

Answer 1

确定解决：识别布局中的“隐藏”部分并将其保存在视图中就足够了。

Answer 2

尝试在 viewholder 构造函数中添加隐藏部分并膨胀管理它的视图