上面的每个答案都是正确的，我也想添加一个快照从我的工作代码。

recycler.addOnScrollListener(new RecyclerView.OnScrollListener() {
        @Override
        public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
            super.onScrollStateChanged(recyclerView, newState);
           // Some code when initially scrollState changes
        }

        @Override
        public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
            super.onScrolled(recyclerView, dx, dy);
            // Some code while the list is scrolling
            LinearLayoutManager lManager = (LinearLayoutManager) recyclerView.getLayoutManager();
            int firstElementPosition = lManager.findFirstVisibleItemPosition();
            
        }
    });

以下线性/网格LayoutManager方法可用于检查哪些项是可见的。

int findFirstVisibleItemPosition();
int findLastVisibleItemPosition();
int findFirstCompletelyVisibleItemPosition();
int findLastCompletelyVisibleItemPosition();

如果你想跟踪屏幕上可见的项目，那么你可以参考下面的博客。

https://proandroiddev.com/detecting-list-items-perceived-by-user-8f164dfb1d05

对于StaggeredGridLayoutManager执行以下操作:

RecyclerView rv = findViewById(...);
StaggeredGridLayoutManager lm = new StaggeredGridLayoutManager(...);
rv.setLayoutManager(lm);

要获得可见的项目视图:

int[] viewsIds = lm.findFirstCompletelyVisibleItemPositions(null);
ViewHolder firstViewHolder = rvPlantios.findViewHolderForLayoutPosition(viewsIds[0]);
View itemView = viewHolder.itemView;

记得检查它是否为空。

第一个/最后一个可见子节点依赖于LayoutManager。 如果您正在使用LinearLayoutManager或GridLayoutManager，您可以使用

int findFirstVisibleItemPosition();
int findFirstCompletelyVisibleItemPosition();
int findLastVisibleItemPosition();
int findLastCompletelyVisibleItemPosition();

例如:

GridLayoutManager layoutManager = ((GridLayoutManager)mRecyclerView.getLayoutManager());
int firstVisiblePosition = layoutManager.findFirstVisibleItemPosition();

对于LinearLayoutManager，第一个/最后一个取决于适配器的顺序。不要从RecyclerView中查询子元素;LayoutManager可能更倾向于布局比缓存可见的更多的项。

你可以找到recycle视图的第一个和最后一个可见的子视图，并检查你正在寻找的视图是否在范围内:

var visibleChild: View = rv.getChildAt(0)
val firstChild: Int = rv.getChildAdapterPosition(visibleChild)
visibleChild = rv.getChildAt(rv.childCount - 1)
val lastChild: Int = rv.getChildAdapterPosition(visibleChild)
println("first visible child is: $firstChild")
println("last visible child is: $lastChild")

Addendum: The proposed functions findLast...Position() do not work correctly in a scenario with a collapsing toolbar while the toolbar is expanded. It seems that the recycler view has a fixed height, and while the toolbar is expanded, the recycler is moved down, partially out of the screen. As a consequence the results of the proposed functions are too high. Example: The last visible item is told to be #9, but in fact item #7 is the last one that is on screen. This behaviour is also the reason why my view often failed to scroll to the correct position, i.e. scrollToPosition() did not work correctly (I finally collapsed the toolbar programmatically).