android - Recyclerview，CursorAdapter，中间有 Header View

Question

我一直在使用 cursor 和 recyclerview。

我有一个查询游标对象(从加载程序传递)和一个 header 字符串数组[]。

String headers[] = {"apples", "bananas"...};

现在我想将项目显示为

Apples
cursor row 1
cursor row 2
cursor row 3
Bananas
cursor row 4
cursor row 5

我不想使用 getItemCount() 方法进行调整。因此，计划传递具有适当长度的单个游标。

一种可能的方法是使用 MatrixCursor 和 MergeCursor 添加虚拟行，如下所述:Adding rows into Cursor manually .这很好，但是 MergeCursor 会一个接一个地对齐标题和游标数据。

想要探索使用正确的标题和项目位置实现最终光标的方法。

Answer 1

您可以使用图书馆 SectionedRecyclerViewAdapter将您的数据分组并为每个部分添加标题。

首先创建一个Section类:

class MySection extends StatelessSection {

    String title;
    List<String> list;

    public MySection(String title, List<String> list) {
        // call constructor with layout resources for this Section header, footer 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.title.setText(list.get(position));
    }

    @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);
    }
}

然后您使用您的 Sections 设置 RecyclerView:

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

// Add your Sections to the adapter
sectionAdapter.addSection(new MySection(headers[0], applesList));
sectionAdapter.addSection(new MySection(headers[1], bananasList));

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

对于上面的示例，您将不得不研究如何转换您的 Cursor进入List<String>但您可以更改 MySection 类以接收 Cursor而不是 List<String> .