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スクロール中にRecyclerViewが最下部に到達したことを検出

私はRecyclerView用にこのコードを持っています。

    recyclerView = (RecyclerView)rootview.findViewById(R.id.fabric_recyclerView);
    recyclerView.setLayoutManager(layoutManager);
    recyclerView.addItemDecoration(new RV_Item_Spacing(5));
    FabricAdapter fabricAdapter=new FabricAdapter(ViewAdsCollection.getFabricAdsDetailsAsArray());
    recyclerView.setAdapter(fabricAdapter);

スクロール中に、RecyclerViewが最下部に到達するタイミングを知る必要があります。出来ますか ？はいの場合、どのように？

androidscrollandroid-recyclerview
54
Adrian

それを行う簡単な方法もあります

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

        if (!recyclerView.canScrollVertically(1)) {
            Toast.makeText(YourActivity.this, "Last", Toast.LENGTH_LONG).show();

        }
    }
});

方向整数：-1は上、1は下、0は常にfalseを返します。

135
Kaustubh Bhagwat

RecyclerviewにaddOnScrollListener（）を実装するだけです。次に、スクロールリスナー内で以下のコードを実装します。

RecyclerView.OnScrollListener mScrollListener = new RecyclerView.OnScrollListener() {
        @Override
        public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
            if (mIsLoading)
                return;
            int visibleItemCount = mLayoutManager.getChildCount();
            int totalItemCount = mLayoutManager.getItemCount();
            int pastVisibleItems = mLayoutManager.findFirstVisibleItemPosition();
            if (pastVisibleItems + visibleItemCount >= totalItemCount) {
                //End of list
            }
        }
    };
36
Febi M Felix

AnswerはKotlinにあり、Javaで動作します。IntelliJは、コピーして貼り付けると変換されます。

recyclerView.addOnScrollListener(object : RecyclerView.OnScrollListener(){

    override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {

        // 3 lines below are not needed.
        Log.d("TAG","Last visible item is: ${gridLayoutManager.findLastVisibleItemPosition()}")
        Log.d("TAG","Item count is: ${gridLayoutManager.itemCount}")
        Log.d("TAG","end? : ${gridLayoutManager.findLastVisibleItemPosition() == gridLayoutManager.itemCount-1}")

        if(gridLayoutManager.findLastVisibleItemPosition() == gridLayoutManager.itemCount-1){
            // We have reached the end of the recycler view.
        }

        super.onScrolled(recyclerView, dx, dy)
    }
})

これは、上記と同じメソッドを使用するため、LinearLayoutManagerでも機能します。つまり、findLastVisibleItemPosition()およびgetItemCount()（KotlinではitemCount）。

10
daka

繰り返し呼び出しを避けるためにこのコードを使用してください

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

            if (!recyclerView.canScrollVertically(1) && newState==RecyclerView.SCROLL_STATE_IDLE) {
                Log.d("-----","end");

            }
        }
    });
7
Milind Chaudhary

私の実装があり、StaggeredGridLayoutに非常に役立ちます。

使用法：

private EndlessScrollListener scrollListener =
        new EndlessScrollListener(new EndlessScrollListener.RefreshList() {
            @Override public void onRefresh(int pageNumber) {
                //end of the list
            }
        });

rvMain.addOnScrollListener(scrollListener);

リスナーの実装：

class EndlessScrollListener extends RecyclerView.OnScrollListener {
private boolean isLoading;
private boolean hasMorePages;
private int pageNumber = 0;
private RefreshList refreshList;
private boolean isRefreshing;
private int pastVisibleItems;

EndlessScrollListener(RefreshList refreshList) {
    this.isLoading = false;
    this.hasMorePages = true;
    this.refreshList = refreshList;
}

@Override public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
    super.onScrolled(recyclerView, dx, dy);
    StaggeredGridLayoutManager manager =
            (StaggeredGridLayoutManager) recyclerView.getLayoutManager();

    int visibleItemCount = manager.getChildCount();
    int totalItemCount = manager.getItemCount();
    int[] firstVisibleItems = manager.findFirstVisibleItemPositions(null);
    if (firstVisibleItems != null && firstVisibleItems.length > 0) {
        pastVisibleItems = firstVisibleItems[0];
    }

    if (visibleItemCount + pastVisibleItems >= totalItemCount && !isLoading) {
        isLoading = true;
        if (hasMorePages && !isRefreshing) {
            isRefreshing = true;
            new Handler().postDelayed(new Runnable() {
                @Override public void run() {
                    refreshList.onRefresh(pageNumber);
                }
            }, 200);
        }
    } else {
        isLoading = false;
    }
}

public void noMorePages() {
    this.hasMorePages = false;
}

void notifyMorePages() {
    isRefreshing = false;
    pageNumber = pageNumber + 1;
}

interface RefreshList {
    void onRefresh(int pageNumber);
}  }
4
Aleksey Timoshchenko

これを試して

私は上記の回答を使用しましたが、それはあなたがリサイクル業者のビューの最後に行くときに常に実行されます、

下にあるかどうかを一度だけ確認したい場合例：-下に行くたびに10個のアイテムのリストがある場合、スクロールすると再び表示されます上から下に再度印刷されることはありません。さらにリストを追加してそこに移動すると、再び表示されます。

注：- APIをヒットする際にオフセットを扱う場合は、このメソッドを使用します

  1. EndlessRecyclerViewScrollListenerという名前のクラスを作成します

        import Android.support.v7.widget.GridLayoutManager;
    import Android.support.v7.widget.LinearLayoutManager;
    import Android.support.v7.widget.RecyclerView;
    import Android.support.v7.widget.StaggeredGridLayoutManager;

    public abstract class EndlessRecyclerViewScrollListener extends RecyclerView.OnScrollListener {
        // The minimum amount of items to have below your current scroll position
        // before loading more.
        private int visibleThreshold = 5;
        // The current offset index of data you have loaded
        private int currentPage = 0;
        // The total number of items in the dataset after the last load
        private int previousTotalItemCount = 0;
        // True if we are still waiting for the last set of data to load.
        private boolean loading = true;
        // Sets the starting page index
        private int startingPageIndex = 0;

        RecyclerView.LayoutManager mLayoutManager;

        public EndlessRecyclerViewScrollListener(LinearLayoutManager layoutManager) {
            this.mLayoutManager = layoutManager;
        }

    //    public EndlessRecyclerViewScrollListener() {
    //        this.mLayoutManager = layoutManager;
    //        visibleThreshold = visibleThreshold * layoutManager.getSpanCount();
    //    }

        public EndlessRecyclerViewScrollListener(StaggeredGridLayoutManager layoutManager) {
            this.mLayoutManager = layoutManager;
            visibleThreshold = visibleThreshold * layoutManager.getSpanCount();
        }

        public int getLastVisibleItem(int[] lastVisibleItemPositions) {
            int maxSize = 0;
            for (int i = 0; i < lastVisibleItemPositions.length; i++) {
                if (i == 0) {
                    maxSize = lastVisibleItemPositions[i];
                }
                else if (lastVisibleItemPositions[i] > maxSize) {
                    maxSize = lastVisibleItemPositions[i];
                }
            }
            return maxSize;
        }

        // This happens many times a second during a scroll, so be wary of the code you place here.
        // We are given a few useful parameters to help us work out if we need to load some more data,
        // but first we check if we are waiting for the previous load to finish.
        @Override
        public void onScrolled(RecyclerView view, int dx, int dy) {
            int lastVisibleItemPosition = 0;
            int totalItemCount = mLayoutManager.getItemCount();

            if (mLayoutManager instanceof StaggeredGridLayoutManager) {
                int[] lastVisibleItemPositions = ((StaggeredGridLayoutManager) mLayoutManager).findLastVisibleItemPositions(null);
                // get maximum element within the list
                lastVisibleItemPosition = getLastVisibleItem(lastVisibleItemPositions);
            } else if (mLayoutManager instanceof GridLayoutManager) {
                lastVisibleItemPosition = ((GridLayoutManager) mLayoutManager).findLastVisibleItemPosition();
            } else if (mLayoutManager instanceof LinearLayoutManager) {
                lastVisibleItemPosition = ((LinearLayoutManager) mLayoutManager).findLastVisibleItemPosition();
            }

            // If the total item count is zero and the previous isn't, assume the
            // list is invalidated and should be reset back to initial state
            if (totalItemCount < previousTotalItemCount) {
                this.currentPage = this.startingPageIndex;
                this.previousTotalItemCount = totalItemCount;
                if (totalItemCount == 0) {
                    this.loading = true;
                }
            }
            // If it’s still loading, we check to see if the dataset count has
            // changed, if so we conclude it has finished loading and update the current page
            // number and total item count.
            if (loading && (totalItemCount > previousTotalItemCount)) {
                loading = false;
                previousTotalItemCount = totalItemCount;
            }

            // If it isn’t currently loading, we check to see if we have breached
            // the visibleThreshold and need to reload more data.
            // If we do need to reload some more data, we execute onLoadMore to fetch the data.
            // threshold should reflect how many total columns there are too
            if (!loading && (lastVisibleItemPosition + visibleThreshold) > totalItemCount) {
                currentPage++;
                onLoadMore(currentPage, totalItemCount, view);
                loading = true;
            }
        }

        // Call this method whenever performing new searches
        public void resetState() {
            this.currentPage = this.startingPageIndex;
            this.previousTotalItemCount = 0;
            this.loading = true;
        }

        // Defines the process for actually loading more data based on page
        public abstract void onLoadMore(int page, int totalItemsCount, RecyclerView view);

    }

  2. このクラスをこのように使用します

         LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getActivity());
        recyclerView.setLayoutManager(linearLayoutManager);
        recyclerView.addOnScrollListener(new EndlessRecyclerViewScrollListener( linearLayoutManager) {
            @Override
            public void onLoadMore(int page, int totalItemsCount, RecyclerView view) {
                Toast.makeText(getActivity(),"LAst",Toast.LENGTH_LONG).show();
            }
        });

私の終わりには完璧に動作し、問題が発生した場合は私をcomめます

3
Sunil

私もこの質問を探していましたが、満足できる答えが見つからなかったので、recyclerViewの独自の実現を作成しました。

他のソリューションは私のものよりも精度が低くなります。たとえば、最後のアイテムがかなり大きい場合（テキストが大量）、他のソリューションのコールバックがずっと早く来てから、recyclerViewが本当に最下位に達します。

私の解決策はこの問題を修正します。

class CustomRecyclerView: RecyclerView{

    abstract class TopAndBottomListener{
        open fun onBottomNow(onBottomNow:Boolean){}
        open fun onTopNow(onTopNow:Boolean){}
    }


    constructor(c:Context):this(c, null)
    constructor(c:Context, attr:AttributeSet?):super(c, attr, 0)
    constructor(c:Context, attr:AttributeSet?, defStyle:Int):super(c, attr, defStyle)


    private var linearLayoutManager:LinearLayoutManager? = null
    private var topAndBottomListener:TopAndBottomListener? = null
    private var onBottomNow = false
    private var onTopNow = false
    private var onBottomTopScrollListener:RecyclerView.OnScrollListener? = null


    fun setTopAndBottomListener(l:TopAndBottomListener?){
        if (l != null){
            checkLayoutManager()

            onBottomTopScrollListener = createBottomAndTopScrollListener()
            addOnScrollListener(onBottomTopScrollListener)
            topAndBottomListener = l
        } else {
            removeOnScrollListener(onBottomTopScrollListener)
            topAndBottomListener = null
        }
    }

    private fun createBottomAndTopScrollListener() = object :RecyclerView.OnScrollListener(){
        override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
            checkOnTop()
            checkOnBottom()
        }
    }

    private fun checkOnTop(){
        val firstVisible = linearLayoutManager!!.findFirstCompletelyVisibleItemPosition()
        if(firstVisible == 0 || firstVisible == -1 && !canScrollToTop()){
            if (!onTopNow) {
                onTopNow = true
                topAndBottomListener?.onTopNow(true)
            }
        } else if (onTopNow){
            onTopNow = false
            topAndBottomListener?.onTopNow(false)
        }
    }

    private fun checkOnBottom(){
        var lastVisible = linearLayoutManager!!.findLastCompletelyVisibleItemPosition()
        val size = linearLayoutManager!!.itemCount - 1
        if(lastVisible == size || lastVisible == -1 && !canScrollToBottom()){
            if (!onBottomNow){
                onBottomNow = true
                topAndBottomListener?.onBottomNow(true)
            }
        } else if(onBottomNow){
            onBottomNow = false
            topAndBottomListener?.onBottomNow(false)
        }
    }


    private fun checkLayoutManager(){
        if (layoutManager is LinearLayoutManager)
            linearLayoutManager = layoutManager as LinearLayoutManager
        else
            throw Exception("for using this listener, please set LinearLayoutManager")
    }

    private fun canScrollToTop():Boolean = canScrollVertically(-1)
    private fun canScrollToBottom():Boolean = canScrollVertically(1)
}

その後、アクティビティ/フラグメントで：

override fun onCreate() {
    customRecyclerView.layoutManager = LinearLayoutManager(context)
}

override fun onResume() {
    super.onResume()
    customRecyclerView.setTopAndBottomListener(this)
}

override fun onStop() {
    super.onStop()
    customRecyclerView.setTopAndBottomListener(null)
}

それが誰かを助けることを願っています;-)

2
Andriy Antonov

これは私の解決策です：

    val onScrollListener = object : RecyclerView.OnScrollListener() {

    override fun onScrolled(recyclerView: RecyclerView?, dx: Int, dy: Int) {
        directionDown = dy > 0
    }

    override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
        if (recyclerView.canScrollVertically(1).not()
                && state != State.UPDATING
                && newState == RecyclerView.SCROLL_STATE_IDLE
                && directionDown) {
               state = State.UPDATING
            // TODO do what you want  when you reach bottom, direction
            // is down and flag for non-duplicate execution
        }
    }
}
0
Alex Zezekalo

上記の回答では、onScrolledでも2回トリガーされたため、完璧なソリューションを得ることができませんでした。

override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
            super.onScrolled(recyclerView, dx, dy)
           if( !recyclerView.canScrollVertically(RecyclerView.FOCUS_DOWN))
               context?.toast("Scroll end reached")
        }
0
Manoj Perumarath

水平LinearLayoutManager（Kotlin）の私のソリューション：

recyclerView.addOnScrollListener(object : RecyclerView.OnScrollListener() {
                            override fun onScrolled(recyclerView: RecyclerView, dx:Int, dy: Int) {
                                super.onScrolled(recyclerView, dx, dy)

                            if (dx == 0 && !recyclerView.canScrollHorizontally(1)) {
                                //add here your code
                                recyclerView.removeOnScrollListener(this)//remove this listener to prevent leaks
                            }
                        }
                    })
 </ code>

recyclerView.layoutManager？.scrollToPosition（recyclerView.adapter？.itemCount？.minus（1）!!）//最後のアイテム位置までスクロールしてOnScrollListenerをトリガーする
0
Игорь Конюхов

インターフェイスを使用して位置を取得できます

インターフェース：リスナーのインターフェースを作成します

public interface OnTopReachListener { void onTopReached(int position);}

アクティビティ：

mediaRecycleAdapter = new MediaRecycleAdapter(Class.this, taskList); recycle.setAdapter(mediaRecycleAdapter); mediaRecycleAdapter.setOnSchrollPostionListener(new OnTopReachListener() {
@Override
public void onTopReached(int position) {
    Log.i("Position","onTopReached "+position);  
}
});

アダプター：

public void setOnSchrollPostionListener(OnTopReachListener topReachListener) {
    this.topReachListener = topReachListener;}@Override public void onBindViewHolder(MyViewHolder holder, int position) {if(position == 0) {
  topReachListener.onTopReached(position);}}
0
Amuthan S