java - 水平 RecyclerView 中的上一个和下一个按钮

Question

我正在创建电子商务应用程序，我想问你当我单击“下一个”按钮时，RecyclerView 向右移动并显示下一个项目，当我单击“上一个”按钮时，RecyclerView 向左移动并显示上一个项目？

RecyclerView 外部的上一个和下一个按钮:

代码:

private RecyclerView rcTopPicks;
private RecyclerView.Adapter adapter;
private LinearLayoutManager layoutManager;
private ImageView previousTopPicks, nextTopPicks;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_home, container, false);

    previousTopPicks = view.findViewById(R.id.btn_left_top_picks);
    nextTopPicks = view.findViewById(R.id.btn_right_top_picks);

    initView(view);
    getTopPicksData();

    return view;
}

private void initViews(View view) {
    rcTopPicks = view.findViewById(R.id.rc_top_picks);
    layoutManager = new LinearLayoutManager(getContext(), LinearLayoutManager.HORIZONTAL, false);
    rcTopPicks.setLayoutManager(layoutManager);
}

private void getTopPicksData() {
    // Code for get JSON
    ....................
    adapter = new TopPicksAdapter(productList);
    rcTopPicks.setAdapter(adapter);

    // This button is not move to left and not showing 2 previous items
    previousTopPicks.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            rcTopPicks.scrollToPosition(adapter.getItemCount() - 1);
        }
    });

    // This button is not move to right and not showing 2 next items
    nextTopPicks.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            rcTopPicks.scrollToPosition(adapter.getItemCount() + 1);
        }
    });
}

问题是当我点击下一步按钮时如何将recyclerview的位置滚动到右侧？当我单击上一个按钮时，如何将 recyclerview 的位置滚动到左侧？

Answer 1

单击“下一个”和“上一个”按钮，此代码从当前位置滚动到下一个/上一个 View 。

  binding.btPrevImage.setOnClickListener{
        val  imageCurrentPosition=  (binding.rvAllImage.layoutManager as LinearLayoutManager).findFirstVisibleItemPosition()
        if(imageCurrentPosition>0){
            binding.rvAllImage.smoothScrollToPosition(imageCurrentPosition-1)
        }
    }
 binding.btNextImage.setOnClickListener{
        val  imageCurrentPosition=  (binding.rvAllImage.layoutManager as LinearLayoutManager).findLastVisibleItemPosition()
        if(imageCurrentPosition<productImageAdapter.itemCount-1){
            binding.rvAllImage.smoothScrollToPosition(imageCurrentPosition+1)
        }
    }