RecyclerView OnScrollListener()问题

问题描述

我在json中有大约32条记录，我正在使用RecyclerView来显示它们，并且已经实现了OnScrollListener(...)

I have around 32 records in json, I am using RecyclerView to show them and I have implemented OnScrollListener(...)

问题

我开始了一个Activity，我获取了所有32条记录，现在当我滚动时，为什么每次滚动时又一次又一次获得相同的32条记录，这是我对OnScrollListener()的实现

I started an Activity, I fetched all 32 records, now when I do scroll, why I am again getting same 32 records again and again, whenever I do scroll, here is my implementation of OnScrollListener()

public void initializeOnScrollForRecyclerView() {
        mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
            @Override
            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {

                int visibleItemCount = recyclerView.getLayoutManager().getChildCount();
                int totalItemCount = recyclerView.getLayoutManager().getItemCount();
                int pastVisiblesItems = ((LinearLayoutManager) recyclerView.getLayoutManager()).findFirstVisibleItemPosition();

                if (!isLoading) {
                    if ((visibleItemCount + pastVisiblesItems) >= totalItemCount) {
                        isLoading = true;
                        mPostPresenter.loadPosts(false);
                    }
                }
            }
        });
    }

推荐答案

实现似乎是正确的，但对于一种情况它失败，请尝试在dy> 0这样的情况下尝试(也将其放在Activity的OnCreate中):

The Implementation seems to be correct but for one condition it fails, try when dy > 0 like this (Also put this in the OnCreate of the Activity) :

    private boolean loading = true;

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


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

            if (loading) {
                if (dy > 0) //check for scroll down
                {
                    visibleItemCount = layoutManager.getChildCount();
                    totalItemCount = layoutManager.getItemCount();
                    pastVisiblesItems = layoutManager.findFirstVisibleItemPosition();

                    if ((visibleItemCount + pastVisiblesItems) >= totalItemCount) {
                        loading = false;

                        Log.v("...", " Reached Last Item");
                        loadMoreVideos(searchVideos);
                    }

                }
            }
        }
    });

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