检查是否错过了在适配器中调用此方法

@Override
public int getItemCount() {
    return list.size();
}

1)创建什么都不做的ViewHolder:)

// SampleHolder.java
public class SampleHolder extends RecyclerView.ViewHolder {
    public SampleHolder(View itemView) {
        super(itemView);
    }
}

2)再次创建RecyclerView，不做任何事情:)

// SampleRecycler.java
public class SampleRecycler extends RecyclerView.Adapter<SampleHolder> {
    @Override
    public SampleHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        return null;
    }

    @Override
    public void onBindViewHolder(SampleHolder holder, int position) {

    }

    @Override
    public int getItemCount() {
        return 0;
    }
}

3)现在，当你真正的回收器还没有准备好时，就使用下面的样品。

RecyclerView myRecycler = (RecyclerView) findViewById(R.id.recycler_id);
myRecycler.setLayoutManager(new LinearLayoutManager(this));
myRecycler.setAdapter(new SampleRecycler());

虽然这不是最好的解决方案，但它确实有效!希望这对你有帮助。

当你在创建阶段没有设置适配器时，会发生这种情况:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity);
    mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
    ....
}

public void onResume() {
    super.onResume();
    mRecyclerView.setAdapter(mAdapter);
    ....
}

只需移动设置适配器到onCreate与一个空数据，当你有数据调用:

mAdapter.notifyDataSetChanged();

我得到了同样的问题，我做的每件事都是正确的，除了在xml文件:

step first 1: initialize recyclerview & List & Adaptor: RecyclerView recyclerview; List<ModelName> list; ProvideBidAdaptor adaptor; step 2: bind it in onCreate- recyclerview = findByViewId(R.id.providerBidRV); recyclerview.setLayoutManager(new LinearLayoutManager(this)); recyclerview.setHasFixedSize(true); list = new ArrayList<>(); step 3: Where you getting response or list - add list- (i am getting from response)> responseList.addAll(response.getResponse()); adaptor = new ProvideBidAdaptor(this, responseList); binding.detailsRV.setAdapter(adaptor);

这是我的xml文件，我实现RecyclerView: 我忘记了线性布局的方向，经过这个修正- RecyclerView附加。

<?xml version="1.0" encoding="utf-8"?>
    <layout>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        tools:context=".activities.Bidding.ProvideBid">

        <include
            android:id="@+id/toolbar"
            layout="@layout/app_toolbar"/>

        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/providerBidRV"
            android:layout_width="match_parent"
            android:layout_height="match_parent"/>
    </LinearLayout>
</layout> 

这是适配器:

    public class ProvideBidAdaptor extends RecyclerView.Adapter<ProvideBidAdaptor.ViewHolder> {
    Context context;
    List<Response> responseList;
    DateTime dateTimeInstance = new DateTime();

    public ProvideBidAdaptor(Context context, List<Response> responseList) {
        this.context = context;
        this.responseList = responseList;
    }

    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(context).inflate(R.layout.geo_presence_item_list, parent, false);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        final Response detailsResponse = responseList.get(position);
        if (!detailsResponse.getUserId().isEmpty()) {

            holder.day.setText(detailsResponse.getDay());
            holder.locationType.setText(detailsResponse.getLocationType());

        }

    }

    @Override
    public int getItemCount() {
        return responseList.size();
    }

    public class ViewHolder extends RecyclerView.ViewHolder {
        TextView date,locationType;
        CardView provideBidCV;
        LinearLayout dayLLayout,locationTypeLLayout;
        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            date = itemView.findViewById(R.id.date_value);
            day = itemView.findViewById(R.id.day_value);
            locationType = itemView.findViewById(R.id.locationType_value);

            locationTypeLLayout = itemView.findViewById(R.id.locationTypeLLayout);

        }
    }
}

我有这个错误，我试着修复了一段时间，直到我找到解决方案。

我做了一个私有方法buildRecyclerView，我调用它两次，第一次在onCreateView，然后在我的回调(其中我从API获取数据)。这是我的方法buildRecyclerView在我的片段:

private void buildRecyclerView(View v) {
        mRecyclerView = v.findViewById(R.id.recycler_view_loan);
        mLayoutManager = new LinearLayoutManager(getActivity());
        ((LinearLayoutManager) mLayoutManager).setOrientation(LinearLayoutManager.VERTICAL);
        mRecyclerView.setLayoutManager(mLayoutManager);
        mAdapter = new LoanAdapter(mExampleList);
        mRecyclerView.setLayoutManager(mLayoutManager);
        mRecyclerView.setAdapter(mAdapter);
}

此外，我必须修改我的适配器中的get-Item-Count方法，因为On - On - create - view列表是空的，它通过一个错误。所以，我的get-Item-Count如下所示:

@Override
    public int getItemCount() {
        try {
            return mLoanList.size();
        } catch (Exception ex){return 0;}

    }

在我的情况下，它是一个被遗忘的组件，位于ViewHolder类，但它不在布局文件中