在向下滚动时,recyclelerview内部的嵌套scrollview不会触发onscrolllistener

Question

编辑:

我从webservice加载了200多个数据.当我向下滚动recyclerview时,它不会触发scrollLisener.

因为,如果我没有使用dy> 0条件,它将加载所有接下来的20个数据,20个数据,依此类推,最初是在进行此活动时.

下面我发布了相关的代码.

logcat的:

E/dy: 0

活动代码:

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);
        }
    }
}

当我最初参加这个活动时,我的dy为0.当我滚动时RecyclerView,dy没有触发LogCat.

我认为因为NestedScrollView它不起作用.但我需要嵌套滚动视图,因为我需要向下滚动一些视图RecyclerView.

Answer 1

如果它是懒加载你想要看看我的 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.

Answer 2

试试这对我有用....

nestedScrollView.setOnScrollChangeListener((NestedScrollView.OnScrollChangeListener) (v, scrollX, scrollY, oldScrollX, oldScrollY) -> {
        if(v.getChildAt(v.getChildCount() - 1) != null) {
            if ((scrollY >= (v.getChildAt(v.getChildCount() - 1).getMeasuredHeight() - v.getMeasuredHeight())) &&
                    scrollY > oldScrollY) {
                    //code to fetch more data for endless scrolling
            }
        }
    });

参考：NestedScrollView