试试这个

Question

我有一个RecyclerView的代码。

    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);

我需要知道RecyclerView在滚动时何时到达最底部位置。可能吗？如果是，怎么样？

Answer 1

还有一种简单的方法可以做到这一点

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表示向上，1表示向下，0表示总是返回false。

Answer 2

只需在recyclerview上实现addOnScrollListener（）。然后在滚动侦听器内部实现下面的代码。

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
            }
        }
    };

Answer 3

答案在Kotlin中，它将在Java中运行。如果您复制并粘贴，IntelliJ应该为您进行转换。

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)
    }
})

这也适用于LinearLayoutManager，因为它具有与上面相同的方法。即findLastVisibleItemPosition()和getItemCount()（在Kotlin中为itemCount）。

Answer 4

有我的实现，它对StaggeredGridLayout非常有用。

用法：

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

rvMain.addOnScrollListener(scrollListener);

监听器实施：

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);
}  }

Answer 5

试试这个

我已经使用了上面的答案，它总是在你回收垃圾邮件视图结束时运行，

如果您只想检查一次是否在底部？ 示例： - 如果我有10个项目的列表，每当我进入底部时它会显示我，如果我从上到下滚动它将不会再次打印，如果你添加更多列表然后你去那里它将再次显示。

注意：在点击API处理偏移量时使用此方法

创建一个名为EndlessRecyclerViewScrollListener

的类

    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);

    }

像这样使用这个类

     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();
            }
        });

如果你遇到任何问题，它会在我的最后完美运行，如果你有问题

Answer 6

使用 Kotlin

   recyclerView.addOnScrollListener(object : RecyclerView.OnScrollListener() {
            override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
                if (!recyclerView.canScrollVertically(1)) {
                    Toast.makeText(context, "Last", Toast.LENGTH_LONG).show();
                }
            }
        })

Answer 7

我也在寻找这个问题，但我找不到让我满意的答案，所以我创建了自己的recyclerView实现。

其他解决方案不如我的那么精确。例如：如果最后一项很大（很多文本），那么其他解决方案的回调将会更早出现，然后recyclelerView真正达到最低点。

我的解决方案解决了这个问题。

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)
}

然后在你的活动/片段中：

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

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

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

希望它会帮助某人; - ）

Answer 8

对这个线程中的大多数其他答案都不满意之后，我发现我认为更好的东西不在这里。

recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
    @Override
    public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
        if (!recyclerView.canScrollVertically(1) && dy > 0)
        {
             //scrolled to bottom
        }else if (!recyclerView.canScrollVertically(-1) && dy < 0)
        {
            //scrolled to bottom
        }
    }
});

这很简单，当您滚动到顶部或底部时，在所有情况下都将恰好击中一次。

Answer 9

使用此代码避免重复通话

        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");

            }
        }
    });

Answer 10

我已经看到很多关于这个问题的回答，我认为所有回答都没有给出准确的行为结果。但是，如果您遵循这种方法，我相信您会获得最佳行为。

rvCategories 是您的 RecyclerView

categoriesList 是传递给您的适配器的列表

binding.rvCategories.addOnScrollListener(object : RecyclerView.OnScrollListener() {
  override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
            val position = (recyclerView.layoutManager as LinearLayoutManager).findLastCompletelyVisibleItemPosition()
            if (position + 1 == categoriesList.size) {
               // END OF RECYCLERVIEW IS REACHED
            } else {
                // END OF RECYCLERVIEW IS NOT REACHED
            }
    }
})

Answer 11

我无法通过上述答案获得完美的解决方案，因为它甚至在onScrolled上触发了两次

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")
        }

Answer 12

我对水平LinearLayoutManager（Kotlin）的解决方案：

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
                            }
                        }
                    })


recyclerView.layoutManager?.scrollToPosition(recyclerView.adapter?.itemCount?.minus(1)!!)//scroll to last item position to trigger OnScrollListener

Answer 13

我们可以使用Interface获取职位

接口： 为侦听器创建接口

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

活动：

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

适配器：

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

Answer 14

这是我的解决方案：

    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
        }
    }
}

Answer 15

你可以使用这个，如果你放了 1 那会在你留在列表末尾时被指示，如果你现在想要当你留在列表的开头时，你将 1 更改为 -1

recyclerChat.addOnScrollListener(object : RecyclerView.OnScrollListener() {
        override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
            super.onScrollStateChanged(recyclerView, newState)
            if (!recyclerView.canScrollVertically(1)) {
               
            }
        }
    })

Answer 16

Kotlin 答案：

<块引用>

您可以将此 Kotlin 函数用于底部滚动跟随的最佳实践，以创建无限或无限滚动.

// Scroll listener.
private fun setupListenerPostListScroll() {
    val scrollDirectionDown = 1 // Scroll down is +1, up is -1.
    var currentListSize = 0

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

            override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
                super.onScrollStateChanged(recyclerView, newState)

                if (!recyclerView.canScrollVertically(scrollDirectionDown)
                    && newState == RecyclerView.SCROLL_STATE_IDLE
                ) {
                    val listSizeAfterLoading = recyclerView.layoutManager!!.itemCount

                    // List has more item.
                    if (currentListSize != listSizeAfterLoading) {
                        currentListSize = listSizeAfterLoading

                        // Get more posts.
                        postListScrollUpAction(listSizeAfterLoading)
                    }
                    else { // List comes limit.
                        showToastMessageShort("No more items.")
                    }
                }
            }
        })
}

Answer 17

这是我阅读了这篇文章中的所有答案后的解决方案。我只想在列表末尾显示最后一项并且 loading 长度大于屏幕高度时显示 listview，这意味着如果列表中只有一两个项目，则不会显示loading。

private var isLoadMoreLoading: Boolean = false

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

    override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
        super.onScrollStateChanged(recyclerView, newState)

        if (!isLoadMoreLoading) {
            if (linearLayoutManager.findLastCompletelyVisibleItemPosition() == (list.size-1)) {
                if (recyclerView.canScrollVertically(-1)) {

                    adapter?.addLoadMoreView()
                    loadMore()
                }
            }
        }
    }
})

private fun loadMore() {
    isLoadMoreLoading = true
    //call loadMore api
}

因为这个linearLayoutManager.findLastCompletelyVisibleItemPosition() == (list.size-1)，我们可以知道最后一项被显示了，但我们还需要知道listview是否可以滚动。

因此我添加了 recyclerView.canScrollVertically(-1)。一旦到达列表底部，它就无法再向下滚动。 -1 表示列表可以向上滚动。这意味着 listview 长度大于屏幕高度。

这个答案在 kotlin 中。

检测RecyclerView在滚动时何时到达最底部位置

17 个答案:

试试这个