RecyclerView滚动侦听器的方法onscolled调用自动而不滚动

Question

在实施分页时.我遇到了这个问题.不滚动onscrolled方法不断调用.请检查下面的代码.

作为参考,我正在使用带有AdapterViews和RecyclerView的Endless Scrolling

还有一个演示的例子此.

我正在从API请求数据.所以我实施了凌空.安装完成后,发生了奇怪的事情 OnScrolled方法连续调用而不滚动.以下是我的代码.

    HomeFragment.java

    view = inflater.inflate(R.layout.fragment_home, container, false);

    tvNoDataFound = (TextView) view.findViewById(R.id.tv_no_data_found);
    recyclerView = (RecyclerView)view.findViewById(R.id.listView);

    linearLayoutManager = new LinearLayoutManager(getActivity());

    recyclerView.setNestedScrollingEnabled(false);

    recyclerView.setLayoutManager(linearLayoutManager);


    context = view.getContext();

    // Lookup the swipe container view
    swipeProjects = (SwipeRefreshLayout)view.findViewById(R.id.swipeProjects);

    // Setup refresh listener which triggers new data loading
    swipeProjects.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
        @Override
        public void onRefresh() {
            // Your code to refresh the list here.
            // Make sure you call swipeContainer.setRefreshing(false)
            // once the network request has completed successfully.
            getProjects(0,0);
        }
    });
    // Configure the refreshing colors
    swipeProjects.setColorSchemeResources(android.R.color.holo_blue_bright,
            android.R.color.holo_green_light,
            android.R.color.holo_orange_light,
            android.R.color.holo_red_light);

    List<LatestProject> getLatest = getProjects(0,0);

    recyclerView.addOnScrollListener(new EndlessRecyclerViewScrollListener(linearLayoutManager) {

        @Override
        public void onLoadMore(int page, int totalItemsCount) {

            Log.e("here scrolling","scrolling---"+page+"---"+totalItemsCount);

            // Triggered only when new data needs to be appended to the list
            // Add whatever code is needed to append new items to the bottom of the list
            List<LatestProject> getLatest = getProjects(totalItemsCount,page);
        }
    });
return view;

从服务器获得响应后,我使用下面的函数来设置适配器.

public List<LatestProject> returnProjects(List<LatestProject> list, int offset, int curSizes){

    if(offset!=0){
        int curSize = adapter.getItemCount();
        latestProjectsList.addAll(list);
        adapter.notifyItemRangeInserted(curSize, list.size() - 1);
    }else{
        latestProjectsList = list;
        adapter = new ProjectListAdapter(list,getActivity(),HomeFragment.this);
        recyclerView.setAdapter(adapter);
    }
    return list;
}

在上面的代码中,我的第一个API调用偏移0.我不知道是什么问题.是因为凌空异步请求吗？

Answer 1

是的，它会被调用。为了克服这一点，请使用一种方法

private boolean isLastItemDisplaying(RecyclerView recyclerView) {
    if (recyclerView.getAdapter().getItemCount() != 0) {
        int lastVisibleItemPosition = ((LinearLayoutManager) recyclerView.getLayoutManager()).findLastCompletelyVisibleItemPosition();
        if (lastVisibleItemPosition != RecyclerView.NO_POSITION && lastVisibleItemPosition == recyclerView.getAdapter().getItemCount() - 1)
            return true;
    }
    return false;
}

现在onScolled使用该方法进行方法检查。

 boolean a = isLastItemDisplaying(recycler_product);
 if(a)
     {
        List<LatestProject> getLatest = getProjects(totalItemsCount,page);
     }

Answer 2

recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
            @Override
            public void onScrollStateChanged(@NonNull RecyclerView recyclerView, int newState) {
                super.onScrollStateChanged(recyclerView, newState);
            }

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

                LinearLayoutManager linearLayoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();

                if (!isLoading) {
                    if (linearLayoutManager != null && linearLayoutManager.findLastCompletelyVisibleItemPosition() == rowsArrayList.size() - 1) {
                        //bottom of list!
                        loadMore();
                        isLoading = true;
                    }
                }
            }
        });

资料来源：JournalDev