带有多个 ArrayLists 的 Sticky Header RecyclerView

Question

我正在使用RecyclerView 实现粘性标头。我有三个部分（即 3 个粘性标题），它们工作正常。现在我在每个部分中获取了三个数组列表，我已经在我的适配器中初始化了这些列表，我试图根据里面的标题 id 获取这些列表的数据onBindViewHolder。但它并没有给我完整的列表，只是每个列表中的一个字符串（即在第一部分 - mylist 第一位置的数据，，，在第二部分 - mylist1 第二位置的数据 - 在第三部分 - - mylist2) 的第三个位置的数据

请帮忙！！

上下文代码：

StickyTestAdapter

public class StickyTestAdapter extends RecyclerView.Adapter<StickyTestAdapter.ViewHolder> implements
        StickyHeaderAdapter<StickyTestAdapter.HeaderHolder> {

    private Context mContext;
    private ArrayList<String> mylist;
    private ArrayList<String> mylist1;
    private ArrayList<String> mylist2;
    private static  int countposition;
    private String HEADER_FIRIST="HEADER_FIRIST";
    private String HEADER_SECOND="HEADER_SECOND";
    private String HEADER_THIRD="HEADER_THIRD";

    public StickyTestAdapter(Context context) {
        prepareData();
        prepareData1();
        prepareData2();
        this.mContext=context;
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
        final View view = LayoutInflater.from(mContext).inflate(R.layout.item_test, viewGroup, false);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(ViewHolder viewHolder, int position) {


       long rowType= getHeaderId(position);
        Log.e("getHeaderId----",""+rowType);

        if (rowType==0){

            if(!mylist.equals(""))
            {
                Log.e("list_data----", "" + mylist.get(position));
                viewHolder.item.setText(mylist.get(position));
            }
            else
            {
                Log.e("Error--0--", "" + "error");
            }


        } else if (rowType==1){

            if(!mylist1.equals(""))
            {
                Log.e("list_data1----", "" + mylist1.get(position));
                viewHolder.item.setText(mylist1.get(position));
            }
            else
            {
                Log.e("Error---1-", "" + "error");
            }

        } else if (rowType==2){

            if(!mylist2.equals(""))
            {
                Log.e("list_data2----", "" + mylist2.get(position));
                viewHolder.item.setText(mylist2.get(position));
            }
            else
            {
                Log.e("Error----2", "" + "error");
            }
        }
    }


    @Override
    public int getItemCount() {

        if (getHeaderId(countposition)==0){
            Log.e("mylist",""+mylist.size());
            return mylist.size();


        }else  if (getHeaderId(countposition)==1){
            Log.e("mylist1",""+mylist1.size());
            return mylist1.size();
        }else if (getHeaderId(countposition)==2){
            Log.e("mylist2",""+mylist2.size());
            return mylist2.size();
        }
        return 0;
    }

    @Override
    public long getHeaderId(int pos) {
        return pos;
    }

    @Override
    public HeaderHolder onCreateHeaderViewHolder(ViewGroup parent) {
        final View view = LayoutInflater.from(mContext).inflate(R.layout.header_test, parent, false);

        return new HeaderHolder(view);
    }

    @Override
    public void onBindHeaderViewHolder(HeaderHolder viewholder, int count) {
       countposition=count;

        if (getItemViewType(count)==0){
            viewholder.headertext.setText(HEADER_FIRIST);

        }else  if (getItemViewType(count)==1){
            viewholder.headertext.setText(HEADER_SECOND);

        }else if (getItemViewType(count)==2){
            viewholder.headertext.setText(HEADER_THIRD);
        }

    }


    static class ViewHolder extends RecyclerView.ViewHolder {
        public TextView item;

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

            item = (TextView)itemView.findViewById(R.id.text_item);
        }
    }

    static class HeaderHolder extends RecyclerView.ViewHolder {
        public TextView headertext;

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

            headertext = (TextView)itemView.findViewById(R.id.header_text);
        }
    }

    @Override
    public int getItemViewType(int position) {
        return position;
    }



    public void prepareData()
    {
        mylist=new ArrayList<>();
        mylist.add("rajendra");
        mylist.add("rani");
        mylist.add("rahul");
    }

    public void prepareData1()
    {
        mylist1=new ArrayList<>();
        mylist1.add("ravi");
        mylist1.add("vikram");
        mylist1.add("rakesh");

    }

    public void prepareData2()
    {
        mylist2=new ArrayList<>();
        mylist2.add("apple");
        mylist2.add("ashok");
        mylist2.add("vikash");

    }


}

Answer 1

问题很老了。但是该代码看起来很难阅读，我个人尝试不通过创建库来重新发明其他人做得很好的东西。 GitHub 有很多可以导入的源代码。一些示例：FlexibleAdapter、FastAdapter、Epoxy 等。

我已经构建了第一个，但您也可以尝试其他的。 对于我来说，拥有多个视图和带有部分的标题非常容易，我在这里指出 wiki page 我在其中定义部分以及如何初始化它。

除了此功能之外，您还拥有很多更多功能，让您的生活更轻松。

Answer 2

我根据字母表将arraylist分为3个部分，如联系人列表。

为此我使用SectionedRecyclerViewAdapter

MainActivity.java

public class MainActivity extends AppCompactActivity {

private SectionedRecyclerViewAdapter sectionAdapter;

@Override
public View onCreate(Bundle savedInstanceState) {

    setContentView(R.layout.activity_main);
    sectionAdapter = new SectionedRecyclerViewAdapter();


    for(char alphabet = 'a'; alphabet <= 'z';alphabet++) {
        List<String> contacts = getContactsWithLetter(alphabet);

        if (contacts.size() > 0) {
            sectionAdapter.addSection(new ContactsSection(String.valueOf(alphabet), contacts));
        }
    }

    RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerview);
    recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
    recyclerView.setAdapter(sectionAdapter);

    return view;
}

@Override
public void onResume() {
    super.onResume();

    if (getActivity() instanceof AppCompatActivity) {
        AppCompatActivity activity = ((AppCompatActivity) getActivity());
        if (activity.getSupportActionBar() != null)
            activity.getSupportActionBar().setTitle(R.string.nav_example1);
    }
}

private List<String> getContactsWithLetter(char letter) {
    List<String> contacts = new ArrayList<>();

    for (String contact : getResources().getStringArray(R.array.names_)) {
        if (contact.charAt(0) == letter) {
            contacts.add(contact);
        }
    }

    return contacts;
}

private class ContactsSection extends StatelessSection {

    String title;
    List<String> list;

    ContactsSection(String title, List<String> list) {
        super(new SectionParameters.Builder(R.layout.section_ex1_item)
                .headerResourceId(R.layout.section_ex1_header)
                .build());

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

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

    @Override
    public RecyclerView.ViewHolder getItemViewHolder(View view) {
        return new ItemViewHolder(view);
    }

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

        String name = list.get(position);

        itemHolder.tvItem.setText(name);
        itemHolder.imgItem.setImageResource(name.hashCode() % 2 == 0 ? R.drawable.ic_face_black_48dp : R.drawable.ic_tag_faces_black_48dp);

        itemHolder.rootView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(getContext(), String.format("Clicked on position #%s of Section %s", sectionAdapter.getPositionInSection(itemHolder.getAdapterPosition()), title), Toast.LENGTH_SHORT).show();
            }
        });
    }

    @Override
    public RecyclerView.ViewHolder getHeaderViewHolder(View view) {
        return new HeaderViewHolder(view);
    }

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

        headerHolder.tvTitle.setText(title);
    }
}

private class HeaderViewHolder extends RecyclerView.ViewHolder {

    private final TextView tvTitle;

    HeaderViewHolder(View view) {
        super(view);

        tvTitle = (TextView) view.findViewById(R.id.tvTitle);
    }
}

private class ItemViewHolder extends RecyclerView.ViewHolder {

    private final View rootView;
    private final ImageView imgItem;
    private final TextView tvItem;

    ItemViewHolder(View view) {
        super(view);

        rootView = view;
        imgItem = (ImageView) view.findViewById(R.id.imgItem);
        tvItem = (TextView) view.findViewById(R.id.tvItem);
    }
}
}

Answer 3

使用类似于

的结构

    public class MultiArray<T> {

    List<ItemGroup> lists = new ArrayList<>();

    public void addList(String headerText, List<T> list) {
        lists.add(new ItemGroup(headerText, list));
    }

    public int itemCount() {
        int count = 0;
        for (ItemGroup group : lists) {
            count += group.count();
        }
        return count;
    }

    public T getItem(int position) {
        int count = 0;
        for (ItemGroup group : lists) {
            if (count + group.count() >= position) {
                return group.item(position - count);
            }
            count += group.count();

        }
        return null;
    }

    public int getGroupIndex(int position) {
        int count = 0;
        int groupIndex = 0;
        for (ItemGroup group : lists) {
            if (count + group.count() >= position) {
                return groupIndex;
            }
            count += group.count();
            groupIndex++;
        }
        return -1;
    }

    public String getHeaderText(int position){
        int count = 0;

        for (ItemGroup group : lists) {
            if (count + group.count() >= position) {
                return group.headerText;
            }
            count += group.count();
        }
        return "";
    }


    class ItemGroup {
        public final String headerText;
        public final List<T> list;

        public ItemGroup(String headerText, List<T> list) {
            this.headerText = headerText;
            this.list = list;
        }

        public int count() {
            return list.size();
        }

        public T item(int position) {
            return list.get(position);
        }
    }

}

您可以优化它以获得更快的性能