Android 设置二级列表的adapter 父列表有一个 子数据多个 demo、

好的，以下是一个简单的二级列表的demo，父列表有一个子数据多个的情况。

首先是XML布局文件，包含一个ExpandableListView控件：

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

接下来是ExpandableListAdapter的实现，包含两个数据集：parentList和childList。parentList包含父列表项的数据，childList是一个Map，包含每个父列表项下的所有子列表项。在本例中，每个父列表项只有一个子列表项。

public class MyExpandableListAdapter extends BaseExpandableListAdapter {

    private String[] parentList = {"Parent 1", "Parent 2", "Parent 3"};
    private Map<String, String[]> childList = new HashMap<>();

    public MyExpandableListAdapter() {
        childList.put("Parent 1", new String[]{"Child 1"});
        childList.put("Parent 2", new String[]{"Child 1", "Child 2", "Child 3"});
        childList.put("Parent 3", new String[]{"Child 1", "Child 2"});
    }

    @Override
    public int getGroupCount() {
        return parentList.length;
    }

    @Override
    public int getChildrenCount(int groupPosition) {
        String parent = parentList[groupPosition];
        return childList.get(parent).length;
    }

    @Override
    public Object getGroup(int groupPosition) {
        return parentList[groupPosition];
    }

    @Override
    public Object getChild(int groupPosition, int childPosition) {
        String parent = parentList[groupPosition];
        return childList.get(parent)[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 parentText = (String) getGroup(groupPosition);
        if (convertView == null) {
            LayoutInflater inflater = LayoutInflater.from(parent.getContext());
            convertView = inflater.inflate(android.R.layout.simple_expandable_list_item_1, parent, false);
        }
        TextView textView = convertView.findViewById(android.R.id.text1);
        textView.setText(parentText);
        return convertView;
    }

    @Override
    public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
        String childText = (String) getChild(groupPosition, childPosition);
        if (convertView == null) {
            LayoutInflater inflater = LayoutInflater.from(parent.getContext());
            convertView = inflater.inflate(android.R.layout.simple_list_item_1, parent, false);
        }
        TextView textView = convertView.findViewById(android.R.id.text1);
        textView.setText(childText);
        return convertView;
    }

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

在Activity中，获取ExpandableListView控件并设置ExpandableListAdapter：

ExpandableListView expandableListView = findViewById(R.id.expandableListView);
expandableListView.setAdapter(new MyExpandableListAdapter());

通过以上代码，您可以创建一个简单的二级列表，父列表项只有一个子列表项。如果您需要在父列表项下显示多个子列表项，只需要在childList中添加多个子列表项即可。