在适配器内部使用 RecyclerView

Question

这可能有点令人困惑，但请耐心等待并发表评论以进行澄清。我在适配器中使用 RecyclerView。这是因为我希望 ListView 中的多行可以水平滚动。行数完全没问题，但每行中的项目数是错误的。第一行显示正确的行数，但是当我只想要一个时，后面的行在每行中显示多个项目。第 1 行显示 1 个项目（这是我想要的），第 2 行显示 2 个项目，第 3 行显示 3 个项目等。这是我调用第一个适配器的片段文件：

public class featured_fragment extends android.support.v4.app.Fragment {

    public  ArrayList<featured_post> featured_post_list = new ArrayList<>();
    private RecyclerView recyclerView;

    public featured_fragment() {

    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {



        View view = inflater.inflate(R.layout.featured_activity, container, false);
        ListView listView = view.findViewById(R.id.featured_list);
        featuredAdapter adapter = new featuredAdapter(getContext(),featured_post_list);
        listView.setAdapter(adapter);

        //Row 1
        featured_post post = new featured_post();
        adapter.add(post);

        //Row 2
        featured_post post1 = new featured_post();
        adapter.add(post1);

        //Row 3
        featured_post post2 = new featured_post();
        adapter.add(post2);

        return view;

    }
}

我的第一个调用回收器适配器的适配器：

public class featuredAdapter extends ArrayAdapter<featured_post>{

private List<featured_post> featured_postList = new ArrayList<>();
private RecyclerView recyclerView;
private recycler_adapter adapter;
private Context context;



public featuredAdapter(Context context, ArrayList<featured_post> users){

    super(context,0,users);
    this.context=context;

}

public View getView(int position, View convertView, ViewGroup parent) {


    featured_post post_item = getItem(position);

    if(convertView == null) {
        convertView = LayoutInflater.from(getContext()).inflate(R.layout.featured_fragment_activity, parent, false);


    recyclerView = convertView.findViewById(R.id.featured_recyclerView);
    recyclerView.setLayoutManager(new LinearLayoutManager(context));

    adapter = new recycler_adapter(context,featured_postList);
    recyclerView.setAdapter(adapter);

    featured_post post = new featured_post(Integer.toString(position));

    featured_postList.add(post);
    }
  return convertView
  }
}

然后，最终的适配器命名为recycler_adapter（请原谅这个适配器，我创建它的时候很困惑）：

public class recycler_adapter extends RecyclerView.Adapter<recycler_adapter.MyViewHolder> {
private List<featured_post> featuredList;
private Context context;

public class MyViewHolder extends RecyclerView.ViewHolder {

    public TextView text;
    public MyViewHolder(View view) {

        super(view);
        this.text = view.findViewById(R.id.my_text);

    }
}

public recycler_adapter(Context context,List<featured_post> featuredList) {
    this.featuredList = featuredList;
    this.context = context;

}

@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

    View itemView = LayoutInflater.from(context).inflate(R.layout.recycler_activity,null);
    MyViewHolder viewHolder = new MyViewHolder(itemView);

    return viewHolder;
}

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

    featured_post featured_post = featuredList.get(position);
    holder.text.setText(featured_post.string);
}

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

如能提供有关添加多个项目的原因的任何帮助，我们将不胜感激。

编辑：我通过清除 featuredAdapter 中 getView 方法开头的列表解决了这个问题。但是，我收到一条错误消息：

java.lang.IndexOutOfBoundsException: Inconsistency detected. Invalid item position 2(offset:2).state:4

知道为什么会突然发生这种情况吗？

Answer 1

我终于想出了解决问题的方法。首先，为了确保它不会多次放置相同的元素，我在 featuredAdapater 的 getView 方法中添加了一条语句来清除列表：

featured_postList.clear();

然后，我得到了一个 IndexOutOfBoundsException，因为 clear 语句在方法的开头。相反，我通过将语句放在 if(convertView == null) 语句中解决了这个问题。这解决了我的问题，现在它按预期工作了。

在适配器内部使用 RecyclerView

Using a RecyclerView inside of an adapter

android

adapter

android-recyclerview