【原创】带下划线单选菜单栏-标签Tab

    private RecyclerView mHorizontalSpeciesRecycler;
    private TextView tv[] = new TextView[10];//用于记录选择了哪个种类商品 灰色变红色
    private int i = 0;
    private String index = "name0";//用于标记tv

public void setmHorizontalSpeciesListView() {
    List data = initHorizontalSpeciesData();
    mHorizontalSpeciesRecycler = (RecyclerView) goodsView.findViewById(R.id.main_goods_page_horizontal_species_list);
    RecyclerView.LayoutManager manager = new LinearLayoutManager(getActivity());
    ((LinearLayoutManager) manager).setOrientation(LinearLayoutManager.HORIZONTAL);
    mHorizontalSpeciesRecycler.setLayoutManager(manager);
    mHorizontalSpeciesRecycler.setAdapter(new HorizontalSpeciesListAdapter(data));
}

class HorizontalSpeciesListAdapter extends RecyclerView.Adapter{
    //② 创建ViewHolder
    class VH extends RecyclerView.ViewHolder{
        private final TextView name,selectedBar;
        public VH(View v) {
            super(v);
            v.getLayoutParams().width = getActivity().getWindowManager().getDefaultDisplay().getWidth() / 4 + 30;
            v.getLayoutParams().height = v.getLayoutParams().width / 2 ;
            name = (TextView) v.findViewById(R.id.main_goods_species_name);
            tv[i++] = selectedBar = (TextView) v.findViewById(R.id.main_goods_selected_bar);
        }
    }

    private List mDatas;
    public HorizontalSpeciesListAdapter(List data) {
        this.mDatas = data;
    }

    //③ 在Adapter中实现3个方法
    @Override
    public void onBindViewHolder(final HorizontalSpeciesListAdapter.VH holder, int position) {
        holder.name.setText(mDatas.get(position).getSpeciseName());
        if (mDatas.get(position).getSpeciseName().equals(index)){
            holder.selectedBar.setBackgroundColor(Color.RED);
        }else {
            holder.selectedBar.setBackgroundColor(Color.GRAY);
        }
        holder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //item 点击事件
                try {
                    for (TextView j:tv){
                        j.setBackgroundColor(Color.GRAY);
                    }
                }catch (Exception e){

                }
                holder.selectedBar.setBackgroundColor(Color.RED);
                index = holder.name.getText().toString();
                Toast.makeText(getActivity(),"click",Toast.LENGTH_SHORT).show();
            }
        });
    }

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

    @Override
    public HorizontalSpeciesListAdapter.VH onCreateViewHolder(ViewGroup parent, int viewType) {
        //LayoutInflater.from指定写法
        View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.main_goods_horizontal_species_list, parent, false);
        return new HorizontalSpeciesListAdapter.VH(v);
    }
}

private List initHorizontalSpeciesData(){
    List mainHorizontalList = new ArrayList<>();
    for (int i = 0 ; i < 10 ; i++){
        mainHorizontalList.add(new GoodsSpecies("name" + i));
    }
    return mainHorizontalList;
}