如何将 Hashmap<String,List<Items>> 膨胀到 Recyclerview

Posted 2023-02-25

【中文标题】如何将 Hashmap<String,List<Items>> 膨胀到 Recyclerview

【英文标题】：How to inflate Hashmap<String,List<Items>> into the Recyclerview

【发布时间】：2016-07-20 23:17:15

【问题描述】：

我希望键的字符串必须充当标题，并且列表必须在 RecyclerView 中的该映射键下膨胀。

感谢您的帮助

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

private WeakHashMap<String, List<VideoItem>> mData = new WeakHashMap<>();
private ArrayList<String> mKeys;
ArrayList<WeakHashMap<String,List<VideoItem>>> hashMapArrayList;

public Adapter(WeakHashMap<String, List<VideoItem>> mData, ArrayList<WeakHashMap<String,List<VideoItem>>> hashMapArrayList) 
    this.mData = mData;
    this.hashMapArrayList=hashMapArrayList;
    mKeys = new ArrayList<String>(mData.keySet());


public String getKey(int position)

    return (String) mKeys.get(position);



@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) 
    View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.player_item, parent, false);
    MyViewHolder holder=new MyViewHolder(v);
    return holder;


@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) 
    String key = getKey(position);
    WeakHashMap<String, List<VideoItem>> value = hashMapArrayList.get(position);
    MyViewHolder holder1=(MyViewHolder)holder;
    holder1.header.setText(key);
    holder1.value.setText(value.get( key ).get( position ).getDuration());
    Log.v( "KEY",key );
    Log.v( "VALUE", String.valueOf( value ) );


@Override
public int getItemCount() 
    return (null != hashMapArrayList ? hashMapArrayList.size() : 0);



//    public  ArrayList<WeakHashMap<String,List<VideoItem>>> getItem(int position) 
//        return hashMapArrayList.get(mKeys.get(position));
//    

@Override
public long getItemId(int position) 
    return position;

class MyViewHolder extends RecyclerView.ViewHolder
    TextView header ;
    TextView value;
    public MyViewHolder(View itemView) 
        super(itemView);
        header= (TextView) itemView.findViewById(R.id.header);
        value= (TextView) itemView.findViewById(R.id.task_name);
    

【问题讨论】：

发布您的适配器代码，我们将提供帮助

尝试使用这个：github.com/timehop/sticky-headers-recyclerview

我想在 recyclerview 中使用键作为部分并在这些部分下列出值

我无法使用其他库。

你不能做你想做的事。回收器视图实现（除非你使用或制作一个复杂的库）不能显示嵌套的对象集（在你的情况下是标题和子项）。您需要将所有项目移动到指定不同项目类型的单个数组列表中，然后使用回收站视图的不同视图类型功能显示它们。

【参考方案1】：

您可以使用库SectionedRecyclerViewAdapter 轻松实现它。您可以将项目分组并为每个部分添加标题：

class MySection extends StatelessSection 

    String title;
    List<VideoItem> list;

    public MySection(String title, List<VideoItem> list) 
        // call constructor with layout resources for this Section header and items 
        super(R.layout.section_header, R.layout.section_item);

        this.title = title;
        this.list = list;
    

    @Override
    public int getContentItemsTotal() 
        return list.size(); // number of items of this section
    

    @Override
    public RecyclerView.ViewHolder getItemViewHolder(View view) 
        // return a custom instance of ViewHolder for the items of this section
        return new MyItemViewHolder(view);
    

    @Override
    public void onBindItemViewHolder(RecyclerView.ViewHolder holder, int position) 
        MyItemViewHolder itemHolder = (MyItemViewHolder) holder;

        // bind your view here
        itemHolder.tvItem.setText(list.get(position).getName());
    

    @Override
    public RecyclerView.ViewHolder getHeaderViewHolder(View view) 
        return new SimpleHeaderViewHolder(view);
    

    @Override
    public void onBindHeaderViewHolder(RecyclerView.ViewHolder holder) 
        MyHeaderViewHolder headerHolder = (MyHeaderViewHolder) holder;

        // bind your header view here
        headerHolder.tvItem.setText(title);
    

然后你用你的部分设置 RecyclerView：

// Create an instance of SectionedRecyclerViewAdapter 
SectionedRecyclerViewAdapter sectionAdapter = new SectionedRecyclerViewAdapter();

// Create your sections with the list of data from your HashMap
for(Map.Entry<String, List<VideoItem>> entry : mData.entrySet()) 
    MySection section = new MySection(entry.getKey(), entry.getValue());
    // add your section to the adapter
    sectionAdapter.addSection(section);



// Set up your RecyclerView with the SectionedRecyclerViewAdapter
RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerview);
recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
recyclerView.setAdapter(sectionAdapter);

如果你不能使用 3rd 方库，你可以看看它是如何实现的 here。

【讨论】：

@ymerdrengene 是的，它工作，看看在库中......你需要根据你的需要自定义它......

@ShikhaRatra 感谢您的回复！

【参考方案2】：

试试这个

Map<String, List<String>> maplist = new HashMap<String, List<String>>();
List<String> arraylist = new ArrayList<String>();
arraylist.add("Sample text"); // Add more strings...
maplist.put("key",arraylist); // Add more lists...

【讨论】：

我有正确的数据作为 Map>。我不知道如何在 recyclerview 中正确地膨胀该数据作为键作为标题并在该键下列出