ArtistArrayAdapter adapter = new ArtistArrayAdapter(this, artists);
recyclerView = (RecyclerView) findViewById(R.id.cardList);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setAdapter(adapter);

只要用这个替换上面的代码，它就应该工作了。你所做的错误是在调用布局管理器之前调用了setAdapter(适配器)。

我也犯了同样的错误，我修复了它如果你像我一样在等待数据，使用改造或类似的东西

放在Oncreate之前

private ArtistArrayAdapter adapter;
private RecyclerView recyclerView;

把它们放在Oncreate中

 recyclerView = (RecyclerView) findViewById(R.id.cardList);
 recyclerView.setHasFixedSize(true);
 recyclerView.setLayoutManager(new LinearLayoutManager(this));
 adapter = new ArtistArrayAdapter( artists , R.layout.list_item ,getApplicationContext());
 recyclerView.setAdapter(adapter);

当你收到数据时放

adapter = new ArtistArrayAdapter( artists , R.layout.list_item ,getApplicationContext());
recyclerView.setAdapter(adapter);

现在进入ArtistArrayAdapter类，执行这个操作它会做的是如果数组为空或为空它会让GetItemCount返回0如果不是它会让它成为艺术家数组的大小

@Override
public int getItemCount() {

    int a ;

    if(artists != null && !artists.isEmpty()) {

        a = artists.size();
    }
    else {

        a = 0;

     }

   return a;
}

ArtistArrayAdapter adapter = new ArtistArrayAdapter(this, artists);
recyclerView = (RecyclerView) findViewById(R.id.cardList);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setAdapter(adapter);

只要用这个替换上面的代码，它就应该工作了。你所做的错误是在调用布局管理器之前调用了setAdapter(适配器)。

在我的布局xml文件中，缺少了带有layoutManager的底线。我添加后错误消失了。

   <androidx.recyclerview.widget.RecyclerView
    android:id="@+id/recycler_view_chat"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="1"
    app:layoutManager="LinearLayoutManager"/>

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。

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);

        }
    }
}