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问题:

Recyclerview-无法在滚动回调中调用此方法

郗丰
2023-03-14

请注意:我已经检查了SO上的其他问题,虽然我可以消除错误,但它还有其他问题。

下面是我现有的代码:

我的适配器类:

  public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

        Context context;

        private final int VIEW_TYPE_ITEM = 0;
        private final int VIEW_TYPE_LOADING = 1;
        private IOnLoadMoreListener mIOnLoadMoreListener;

        private int visibleThreshold = 3;
        private int lastVisibleItem, totalItemCount;
        private int[] lastVisibleItems = new int[mStaggeredLayoutManager.getSpanCount()];

        public RecyclerViewAdapter(Context context) {
            this.context = context;

            final StaggeredGridLayoutManager staggeredGridLayoutManager = (StaggeredGridLayoutManager) recyclerView.getLayoutManager();

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

                    totalItemCount = staggeredGridLayoutManager.getItemCount();
                    lastVisibleItems = staggeredGridLayoutManager.findLastVisibleItemPositions(new int[mStaggeredLayoutManager.getSpanCount()]);

                    if (staggeredGridLayoutManager.getSpanCount() == 1) {
                        lastVisibleItem = lastVisibleItems[0];
                    } else if (staggeredGridLayoutManager.getSpanCount() == 2) {
                        lastVisibleItem = Math.max(lastVisibleItems[0], lastVisibleItems[1]);
                    } else if (staggeredGridLayoutManager.getSpanCount() == 3) {
                        lastVisibleItem = Math.max(Math.max(lastVisibleItems[0], lastVisibleItems[1]), lastVisibleItems[2]);
                    }

                    if (!isRefreshing && totalItemCount <= lastVisibleItem + visibleThreshold) {

                        if (mIOnLoadMoreListener != null) {
                            mIOnLoadMoreListener.onLoadMore();
                        }

                        isRefreshing = true;
                    }
                }
            });

        }

        @Override
        public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

            if (viewType == VIEW_TYPE_ITEM) {

                View v = LayoutInflater.from(parent.getContext())
                        .inflate(R.layout.item_recyclerview_shop_fragment, parent, false);
                return new CustomViewHolder(v);
            } else if (viewType == VIEW_TYPE_LOADING) {

                View v = LayoutInflater.from(parent.getContext())
                        .inflate(R.layout.item_recyclerview_loading_shop_fragment, parent, false);
                return new LoadingViewHolder(v);
            }

            return null;
        }

        @Override
        public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {

            Product item = listItems.get(position);

            if (holder.getItemViewType() == VIEW_TYPE_ITEM) {

                CustomViewHolder customViewHolder = (CustomViewHolder) holder;
                Glide.with(context).load(item.getFeaturedSrc()).into(customViewHolder.imageView);

            } else if (holder.getItemViewType() == VIEW_TYPE_LOADING) {

                if (holder instanceof LoadingViewHolder) {
                    LoadingViewHolder loadingViewHolder = (LoadingViewHolder) holder;
                    loadingViewHolder.progressBar.setIndeterminate(true);
                }
            }


        }

        @Override
        public int getItemCount() {
            return listItems == null ? 0 : listItems.size();
        }

        @Override
        public int getItemViewType(int position) {

            if (listItems.get(position) == null) {
                return VIEW_TYPE_LOADING;
            } else {
                return VIEW_TYPE_ITEM;
            }
        }

        public void setOnLoadMoreListener(IOnLoadMoreListener mIOnLoadMoreListener) {
            this.mIOnLoadMoreListener = mIOnLoadMoreListener;
        }


        public class CustomViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {

            ImageView imageView;
            TextView textView;

            String id;

            public CustomViewHolder(View itemView) {
                super(itemView);

                itemView.setOnClickListener(this);
                imageView = (ImageView) itemView.findViewById(R.id.imageView_thumbnail);

            }

            @Override
            public void onClick(View v) {

                int position = getAdapterPosition();

            }
        }

        public class LoadingViewHolder extends RecyclerView.ViewHolder {
            public ProgressBar progressBar;

            public LoadingViewHolder(View progressView) {
                super(progressView);
                progressBar = (ProgressBar) progressView.findViewById(R.id.progressBar);
            }
        }

    }
   mRecyclerViewAdapter.setOnLoadMoreListener(new IOnLoadMoreListener() {
        @Override
        public void onLoadMore() {

            listItems.add(null);

            mRecyclerViewAdapter.notifyItemChanged(listItems.size() - 1);
            mRecyclerViewAdapter.notifyDataSetChanged();

            isProgressVisible = true;

            getDataFromServer(false);

        }
    });
W/RecyclerView: Cannot call this method in a scroll callback. Scroll callbacks mightbe run during a measure & layout pass where you cannot change theRecyclerView data. Any method call that might change the structureof the RecyclerView or the adapter contents should be postponed tothe next frame.
java.lang.IllegalStateException: 

at android.support.v7.widget.RecyclerView.assertNotInLayoutOrScroll(RecyclerView.java:2581)
at android.support.v7.widget.RecyclerView$RecyclerViewDataObserver.onItemRangeChanged(RecyclerView.java:4943)
at android.support.v7.widget.RecyclerView$AdapterDataObservable.notifyItemRangeChanged(RecyclerView.java:11373)
at android.support.v7.widget.RecyclerView$AdapterDataObservable.notifyItemRangeChanged(RecyclerView.java:11364)
at android.support.v7.widget.RecyclerView$Adapter.notifyItemChanged(RecyclerView.java:6652)
at codsiga.com.xx.ShopFragment$1.onLoadMore(ShopFragment.java:148)
at codsiga.com.xx.ShopFragment$RecyclerViewAdapter$1.onScrolled(ShopFragment.java:229)
at android.support.v7.widget.RecyclerView.dispatchOnScrolled(RecyclerView.java:4618)
at android.support.v7.widget.RecyclerView.dispatchLayoutStep3(RecyclerView.java:3679)
at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:3323)
at android.support.v7.widget.RecyclerView.onLayout(RecyclerView.java:3844)
at android.view.View.layout(View.java:17637)
at android.view.ViewGroup.layout(ViewGroup.java:5575)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1741)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1585)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1494)
at android.view.View.layout(View.java:17637)
at android.view.ViewGroup.layout(ViewGroup.java:5575)
at android.support.v4.widget.SwipeRefreshLayout.onLayout(SwipeRefreshLayout.java:636)
at android.view.View.layout(View.java:17637)
at android.view.ViewGroup.layout(ViewGroup.java:5575)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
at android.view.View.layout(View.java:17637)
at android.view.ViewGroup.layout(ViewGroup.java:5575)
at android.support.v4.view.ViewPager.onLayout(ViewPager.java:1795)
at android.view.View.layout(View.java:17637)
at android.view.ViewGroup.layout(ViewGroup.java:5575)
at android.support.design.widget.HeaderScrollingViewBehavior.layoutChild(HeaderScrollingViewBehavior.java:131)
at android.support.design.widget.ViewOffsetBehavior.onLayoutChild(ViewOffsetBehavior.java:42)
at android.support.design.widget.AppBarLayout$ScrollingViewBehavior.onLayoutChild(AppBarLayout.java:1391)
at android.support.design.widget.CoordinatorLayout.onLayout(CoordinatorLayout.java:870)
at android.view.View.layout(View.java:17637)
at android.view.ViewGroup.layout(ViewGroup.java:5575)
at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1079)
at android.view.View.layout(View.java:17637)
at android.view.ViewGroup.layout(ViewGroup.java:5575)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
at android.view.View.layout(View.java:17637)
at android.view.ViewGroup.layout(ViewGroup.java:5575)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1741)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1585)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1494)
at android.view.View.layout(View.java:17637)
at android.view.ViewGroup.layout(ViewGroup.java:5575)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
at android.view.View.layout(View.java:17637)
at android.view.ViewGroup.layout(ViewGroup.java:5575)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1741)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1585)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1494)

03-22 11:36:32.083 3189-3189/codsiga.com.xx W/RecyclerView:    
at android.view.View.layout(View.java:17637)
at android.view.ViewGroup.layout(ViewGroup.java:5575)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:323)
at android.widget.FrameLayout.onLayout(FrameLayout.java:261)
at com.android.internal.policy.DecorView.onLayout(DecorView.java:726)
at android.view.View.layout(View.java:17637)
at android.view.ViewGroup.layout(ViewGroup.java:5575)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2346)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2068)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1254)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6337)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:874)
at android.view.Choreographer.doCallbacks(Choreographer.java:686)
at android.view.Choreographer.doFrame(Choreographer.java:621)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:860)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6119)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)

修改代码查看各种答案:

mRecyclerViewAdapter.setOnLoadMoreListener(new IOnLoadMoreListener() {
            @Override
            public void onLoadMore() {

                recyclerView.post(new Runnable() {
                    @Override
                    public void run() {

                        listItems.add(null);

                        mRecyclerViewAdapter.notifyItemChanged(listItems.size() - 1);
                        mRecyclerViewAdapter.notifyDataSetChanged();

                        isProgressVisible = true;

                        getDataFromServer(false);


                    }
                });
            }
        });

现在,我没有得到错误,但是onLoadMore()每次都被调用两次,并且recyclerview中的视图每次都在刷新。我做错了什么?请参阅logcat输出:

D/xx: Response => {…}
D/xx: Length = 9
D/xx: Query 'SELECT * FROM products' returned 9 rows

D/xx: Response => {…}
D/xx: Length = 9
D/xx: Query 'SELECT * FROM products' returned 18 rows

共有1个答案

常自强
2023-03-14

无法在滚动回调中调用此方法。滚动回调可能是在度量和布局传递期间运行的,在该传递中您无法更改eCyclerView数据。任何可能更改RecyclerView结构或适配器内容的方法调用都应推迟到下一帧。

警告本身就是一种解释。换句话说,您正在更新一个视图,而recyclerview正在计算布局度量值。

哪里出了问题?以下实施-

mRecyclerViewAdapter.notifyItemChanged(listItems.size() - 1);
mRecyclerViewAdapter.notifyDataSetChanged();
recyclerView.post(new Runnable() {
        public void run() {
            // There is no need to use notifyDataSetChanged()
            mRecyclerViewAdapter.notifyItemInserted(allArticles.size() - 1);
        }
    });
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