Question

我有一些物品的回收查看，我想获得屏幕中间项目的索引。现在我只能看到第一个项目的项目索引中间可见，最后一个项目可见。

这是截图： image

这是代码

myList = (RecyclerView) v.findViewById(R.id.frag_penampilanobat_pilih_bentuk);
    final LinearLayoutManager layoutManager
            = new LinearLayoutManager(getActivity(), LinearLayoutManager.HORIZONTAL, false);
    Display display = getActivity().getWindowManager().getDefaultDisplay();
    Point size = new Point();
    display.getSize(size);
    itemWidth = getResources().getDimension(R.dimen.item_width);
    padding = (size.x - itemWidth) / 2;
    firstItemWidth = getResources().getDimension(R.dimen.padding_item_width);

    allPixels = 0;
    ExtraItemsAdapter bentuk_adapter = new ExtraItemsAdapter(0, clone, padding);
    myList.setAdapter(bentuk_adapter);
    myList.addOnScrollListener(new RecyclerView.OnScrollListener() {

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

            int firstPos = layoutManager.findFirstVisibleItemPosition();

            int lastPos = layoutManager.findLastVisibleItemPosition();
            int middle = (Math.abs(lastPos - firstPos) / 2 + firstPos) + 1;

            pos_icon_bentuk = middle;
                source = getActivity().getResources().getDrawable(pengingat_obat_helper.getDrawable(pos_icon_shape));
            bentuk_obat.setBackground(FormatShapeColor.setColor(getActivity(), getColor(), source, pos_icon_warna_1));

        }
    });

我不知道该怎么做。有人有意见吗？任何答案将不胜感激。对不起我的英语不好，感谢

Answer 1

据我所知，你需要中间。这是我的解决方案。

int firstPos = layoutManager.findFirstVisibleItemPosition();
int lastPos  = layoutManager.findLastVisibleItemPosition();

int centerRecyclerView = activityMainBinding.recyclerView.getWidth() / 2;

int minDelta=Integer.MAX_VALUE;
                
int middle = 0;
                
for(int i=firstPos;i<=lastPos;i++) {
    View view = layoutManager.findViewByPosition(i);
    if(view!=null) {
        int positionCenterView = view.getLeft() + (view.getRight() - view.getLeft()) / 2;
        int delta = Math.abs(centerRecyclerView - positionCenterView);
        if(delta<minDelta)
        {
            minDelta=delta;
            middle =i;
        }
    }
}

在屏幕中间获取recyclerview项目索引

1 个答案: