编辑:

我已经从 web 服务加载了 200 多个数据。当我向下滚动 recyclerview 时，它没有触发 scrollLisener。

因为，如果我不使用 dy>0 条件，它会加载所有接下来的 20 个数据，20 个数据等等，最初是在进行此 Activity 时。

下面我贴出了相关的代码。

日志:

E/dy: 0

Activity 代码:

recyclerView = (RecyclerView) findViewById(R.id.rv_list_tab_home_recycler);

recyclerView.setHasFixedSize(true);

mLayoutManager = new LinearLayoutManager(this);

recyclerView.setLayoutManager(mLayoutManager);

//homePostitemsAdapter = new UserPostAdapter(TabHomeActivity.this, homePostItemsList);
homePostitemsAdapter = new TabHomeAdapter(homePostItemsList, recyclerView);

//  recyclerView.setItemAnimator(new DefaultItemAnimator());
recyclerView.setAdapter(homePostitemsAdapter);
recyclerView.setNestedScrollingEnabled(false);

适配器代码:

private int visibleThreshold = 5;
private int lastVisibleItem, totalItemCount;
private boolean loading;
private OnLoadMoreListener onLoadMoreListener;

public TabHomeAdapter(List<HomePostItems> objects, RecyclerView recycle) {

    homePostArrListItems = objects;

    if (recycle.getLayoutManager() instanceof LinearLayoutManager) {

        final LinearLayoutManager linearLayoutManager = (LinearLayoutManager) recycle
                .getLayoutManager();

        Log.e("LinearLayoutManager", "Test");

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

                totalItemCount = linearLayoutManager.getItemCount();
                lastVisibleItem = linearLayoutManager
                                .findLastVisibleItemPosition();
                Log.e("dy", ""+dy);

                if (!loading
                                && totalItemCount <= (lastVisibleItem + visibleThreshold ) && dy > 0) {
                    // End has been reached
                    // Do something

                    Log.e("totalItemCount", ""+totalItemCount);
                    Log.e("lastVisibleItem", ""+lastVisibleItem);
                    Log.e("visibleThreshold", ""+visibleThreshold);
                    Log.e("loading", ""+loading);
                    Log.e("onLoadMoreListener", ""+onLoadMoreListener);

                    if (onLoadMoreListener != null) {;
                        onLoadMoreListener.onLoadMore();
                    }

                    loading = true;
                }

            }
        });
    } 

    public void setLoaded() {
        loading = false;
    }

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

    public void setOnLoadMoreListener(OnLoadMoreListener onLoadMoreListener) {
        this.onLoadMoreListener = onLoadMoreListener;
    }

    public static class ProgressViewHolder extends RecyclerView.ViewHolder {
        public ProgressBar progressBar;
        public ProgressViewHolder(View v) {
            super(v);
            progressBar = (ProgressBar) v.findViewById(R.id.progressBar1);
        }
    }
}

当我最初来到这个 Activity 时，我的 dy 为 0。当我滚动 RecyclerView 时，dy 没有在 LogCat 中触发。

我认为是因为 NestedScrollView 它是 not working .但我需要嵌套 ScrollView ，因为我需要在 RecyclerView 之前向下滚动一些 View 。

最佳答案

如果你想要延迟加载，那么看看我的RecyclerAdapter

@Override
public void onBindViewHolder(VH viewHolder, final int position) {

    // Set Data to Views

    if(position == count) {
        // When last item is reached.

        if (onLoadMoreListener != null) {;
            onLoadMoreListener.onLoadMore();
        }
    }
}

我认为这是实现延迟加载的更简单且相当便宜的方法。

关于android - 向下滚动时，recyclerview 中的嵌套 ScrollView 不会触发 onscrolllistener，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/40103183/