写一个ExpandableListView二级分栏的例子

好的，以下是一个 ExpandableListView 二级分栏的例子：

首先在布局文件中定义 ExpandableListView 和 Adapter：

<ExpandableListView
    android:id="@+id/expandableListView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>

<!-- 定义自定义的 ExpandableListAdapter -->

然后在 Activity 中设置 Adapter 并为 ExpandableListView 设置点击事件：

public class MainActivity extends AppCompatActivity {

    private ExpandableListView expandableListView;
    private ExpandableListAdapter adapter;
    private List<String> listDataHeader;
    private HashMap<String, List<String>> listDataChild;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // 准备数据
        prepareListData();

        // 设置 Adapter
        adapter = new ExpandableListAdapter(this, listDataHeader, listDataChild);
        expandableListView.setAdapter(adapter);

        // 设置点击事件
        expandableListView.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {
            @Override
            public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) {
                Toast.makeText(getApplicationContext(), listDataHeader.get(groupPosition) + " : " + listDataChild.get(listDataHeader.get(groupPosition)).get(childPosition), Toast.LENGTH_SHORT).show();
                return false;
            }
        });
    }

    // 准备数据
    private void prepareListData() {
        listDataHeader = new ArrayList<>();
        listDataChild = new HashMap<>();

        // 添加一级分栏
        listDataHeader.add("Fruits");
        listDataHeader.add("Vegetables");

        // 添加二级分栏
        List<String> fruits = new ArrayList<>();
        fruits.add("Apple");
        fruits.add("Banana");
        fruits.add("Mango");

        List<String> vegetables = new ArrayList<>();
        vegetables.add("Carrot");
        vegetables.add("Tomato");
        vegetables.add("Potato");

        // 将二级分栏添加到对应的一级分栏下
        listDataChild.put(listDataHeader.get(0), fruits);
        listDataChild.put(listDataHeader.get(1), vegetables);
    }
}

最后是 ExpandableListAdapter 的实现：

public class ExpandableListAdapter extends BaseExpandableListAdapter {

    private Context context;
    private List<String> listDataHeader;
    private HashMap<String, List<String>> listDataChild;

    public ExpandableListAdapter(Context context, List<String> listDataHeader, HashMap<String, List<String>> listDataChild) {
        this.context = context;
        this.listDataHeader = listDataHeader;
        this.listDataChild = listDataChild;
    }

    @Override
    public int getGroupCount() {
        return this.listDataHeader.size();
    }

    @Override
    public int getChildrenCount(int groupPosition) {
        return this.listDataChild.get(this.listDataHeader.get(groupPosition)).size();
    }

    @Override
    public Object getGroup(int groupPosition) {
        return this.listDataHeader.get(groupPosition);
    }

    @Override
    public Object getChild(int groupPosition, int childPosition) {
        return this.listDataChild.get(this.listDataHeader.get(groupPosition)).get(childPosition);
    }

    @Override
    public long getGroupId(int groupPosition) {
        return groupPosition;
    }

    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }

    @Override
    public boolean hasStableIds() {
        return false;
    }

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
        String headerTitle = (String) getGroup(groupPosition);
        if (convertView == null) {
            LayoutInflater inflater = (LayoutInflater) this.context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = inflater.inflate(R.layout.list_group, null);
        }
        TextView lblListHeader = convertView.findViewById(R.id.lblListHeader);
        lblListHeader.setTypeface(null, Typeface.BOLD);
        lblListHeader.setText(headerTitle);
        return convertView;
    }

    @Override
    public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
        final String childText = (String) getChild(groupPosition, childPosition);
        if (convertView == null) {
            LayoutInflater inflater = (LayoutInflater) this.context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = inflater.inflate(R.layout.list_item, null);
        }
        TextView txtListChild = convertView.findViewById(R.id.lblListItem);
        txtListChild.setText(childText);
        return convertView;
    }

    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }
}

其中 `list_group.xml` 和 `list_item.xml` 分别是一级分栏和二级分栏的布局文件，可以根据需要自行定义。

以上就是 ExpandableListView 二级分栏的例子，希望能对你有所帮助！