在分组的ListView中显示组标题

public class MyAdapter extends BaseExpandableListAdapter {
    private List<String> groupList; // 分组标题列表
    private List<List<String>> childList; // 子项列表

    public MyAdapter(List<String> groupList, List<List<String>> childList) {
        this.groupList = groupList;
        this.childList = childList;
    }

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

    @Override
    public int getChildrenCount(int groupPosition) {
        return childList.get(groupPosition).size();
    }

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

    @Override
    public Object getChild(int groupPosition, int childPosition) {
        return childList.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 true;
    }

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
        if (convertView == null) {
            convertView = LayoutInflater.from(parent.getContext()).inflate(R.layout.group_item, parent, false);
        }
        TextView groupTitle = convertView.findViewById(R.id.group_title);
        groupTitle.setText(groupList.get(groupPosition));
        return convertView;
    }

    @Override
    public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
        if (convertView == null) {
            convertView = LayoutInflater.from(parent.getContext()).inflate(R.layout.child_item, parent, false);
        }
        TextView childTitle = convertView.findViewById(R.id.child_title);
        childTitle.setText(childList.get(groupPosition).get(childPosition));
        return convertView;
    }

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

ExpandableListView listView = findViewById(R.id.list_view);
MyAdapter adapter = new MyAdapter(groupList, childList);
listView.setAdapter(adapter);