RecyclerView与标题

Question

我正在尝试使用带有标题的TextViews列表（在RecyclerView中）编写一个简单的应用程序。滚动后标题必须调整大小。如果我srcoll列表，我需要将标题的文本大小设置为更大。

首先我想我会使用带有TextView（标题）和RecyclerView（列表）的LinearLayout。但是当我在我的recyclerview上设置onScrollListener并在我的标题（textview）上使用setTextSize（滚动）后，所有内容都“跳”，因为当标题中的文字太大并且使用了第二行和更多行时，标题和列表的高度发生了变化。

所以我发明了我只会制作物品的第一元素的动态改变尺寸的RecyclerView并且它（大多数）工作但我需要在屏幕的第一个位置滚动之后使其“粘性”离开它。

有谁知道如何使用标题制作recyclelerview？ 这是我的第二个想法代码： MainActivity：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    ButterKnife.bind(this);
    layoutManager = new LinearLayoutManager(this);

    recyclerView.setLayoutManager(layoutManager);
    recyclerView.setAdapter(new ItemRecycleAdapter());
    recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
        @Override
        public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
            super.onScrollStateChanged(recyclerView, newState);
        }

        private int MAX_FONT = 30;
        private int MIN_FONT = 15;
        private int MAX_HEIGHT = 150;

        int currentLineCount = 1;

        int totalOffset = 0;

        @Override
        public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
            super.onScrolled(recyclerView, dx, dy);
            totalOffset += dy;

            View child = recyclerView.getChildAt(0);
            TextView textView = (TextView) child.findViewById(R.id.headerText);
            textView.setTextSize(TypedValue.COMPLEX_UNIT_DIP, offsetToFontSize(totalOffset));


        }

        public int offsetToFontSize(int offset) {

            if (offset > MAX_HEIGHT)
                return MIN_FONT;

            float step = ((float) (MAX_FONT - MIN_FONT)) / MAX_HEIGHT;

            return (int) (MIN_FONT + ((float) (MAX_HEIGHT - offset)) * step);

        }

    });


}

RecyclerAdapter：

public static final List<Item> Items = new ArrayList<Item>();

private int MAX_FONT = 30;
private int MIN_FONT = 15;
private int MAX_HEIGHT = 150;


static {
    Items.add(new Item("DUŻY TYTUL n you attach it to the view by calling n you attach it to the view by calling", "", ""));
    Items.add(new Item("", "n you attach it to the view by calling n you attach it to the view by calling ", "Lorem ipsum dolar"));
    Items.add(new Item("", " by calling n you att by calling n you attach it to the ach it to the ", "Lorem ipsum dolar"));
    Items.add(new Item("", "Long text test", "Lorem ipsum dolar"));
    Items.add(new Item("", "Long text testLong text test", "Lorem ipsum dolar"));
    Items.add(new Item("", "Long text test", "Lorem ipsum dolar"));
    Items.add(new Item("", "Long text test", "Lorem ipsum dolar"));
    Items.add(new Item("", "Long text test", "Lorem ipsum dolar"));
    Items.add(new Item("", "Long text test", "Lorem ipsum dolar"));
}


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

@Override
public void onBindViewHolder(ItemViewHolder holder, int position) {
    Item item = Items.get(position);
    if (position > 0){
        holder.header.setVisibility(View.GONE);
    }
    holder.header.setText((item.mHeader));
    holder.text1.setText(item.item1);
    holder.text2.setText(item.item2);

}


@Override
public int getItemCount() {
    return Items.size();
}
@Override
public void onBindViewHolder(ItemViewHolder holder, int position) {
    Item item = Items.get(position);
    if (position > 0){
        holder.header.setVisibility(View.GONE);
    }
    holder.header.setText((item.mHeader));
    holder.text1.setText(item.item1);
    holder.text2.setText(item.item2);

}

public void cos(ItemViewHolder holder, int totalOffset){
    holder.header.setTextSize(TypedValue.COMPLEX_UNIT_DIP, offsetToFontSize(totalOffset));
}

public int offsetToFontSize(int offset) {

    if (offset > MAX_HEIGHT)
        return MIN_FONT;

    float step = ((float) (MAX_FONT - MIN_FONT)) / MAX_HEIGHT;

    return (int) (MIN_FONT + ((float) (MAX_HEIGHT - offset)) * step);

}

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