Android ListView突出显示不适用于BaseAdapter

Question

创建ListView并选择模式为CHOICE_MODE_MULTIPLE_MODAL时，我遇到了问题。我在列表项布局中添加了android:background="?android:attr/activatedBackgroundIndicator"。但我的问题是列表项没有在选择时突出显示。但是动作模式会显示所选项目的数量。

这是我的代码段。如果还不够请评论。

group_layout.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:background="?android:attr/activatedBackgroundIndicator">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/white"
        android:textColor="@color/black"
        android:textSize="20sp"
        android:padding="10dp"
        android:id="@+id/tv_item_head"/>
</LinearLayout>

ListViewFragment.java

public class ListViewFragment extends Fragment {

    private ArrayList<String> listItems;
    ListViewAdapter adapter;
    private Activity mActivity;
    private ListView listView;



    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View root = inflater.inflate(R.layout.fragment_listview, container, false);
        initVariables();
        if(mActivity == null) {
            mActivity = getActivity();
        }
        listView = (ListView) root.findViewById(R.id.list);
        listView.setChoiceMode(AbsListView.CHOICE_MODE_MULTIPLE_MODAL);
        listView.setMultiChoiceModeListener(new callbacks());
        adapter = new ListViewAdapter(listItems, getActivity(), getContext());
        listView.setAdapter(adapter);
        return root;
    }

    private void initVariables() {
        listItems = new ArrayList<>(Arrays.asList("Item 1", "Item 2", "Item 3", "Item 4", "Item 5","Item 6","Item 7"));
    }

    private class callbacks implements ListView.MultiChoiceModeListener {

        @Override
        public void onItemCheckedStateChanged(ActionMode mode,
                                              int position, long id, boolean checked) {
            final int checkedCount = listView.getCheckedItemCount();
            mode.setSubtitle("" + checkedCount + " items selected");
            adapter.checkedItems.put(position, checked);
            adapter.notifyDataSetChanged();
        }

        @Override
        public boolean onCreateActionMode(ActionMode actionMode, Menu menu) {
            MenuInflater inflater = mActivity.getMenuInflater();
            inflater.inflate(R.menu.list_select_menu, menu);
            actionMode.setTitle("Select Items");
            return true;
        }

        @Override
        public boolean onPrepareActionMode(ActionMode actionMode, Menu menu) {
            return true;
        }

        @Override
        public boolean onActionItemClicked(ActionMode actionMode, MenuItem menuItem) {
            switch (menuItem.getItemId()) {
                case R.id.share:
                    Toast.makeText(mActivity, "Shared " + listView.getCheckedItemCount() +
                            " items", Toast.LENGTH_SHORT).show();
                    actionMode.finish();
                    break;
                default:
                    Toast.makeText(mActivity, "Clicked " + menuItem.getTitle(),
                            Toast.LENGTH_SHORT).show();
                    break;
            }
            return true;
        }

        @Override
        public void onDestroyActionMode(ActionMode actionMode) {
            adapter.checkedItems.clear();
            adapter.notifyDataSetChanged();
        }
    }
}

ListViewAdapter.java

public class ListViewAdapter extends BaseAdapter {

    ArrayList<String> listItems;
    Context mContext;
    Activity mActivity;
    SparseBooleanArray checkedItems;

    public ListViewAdapter(ArrayList<String> listItems, FragmentActivity activity, Context context) {
        this.listItems = listItems;
        this.mActivity = activity;
        this.mContext = context;
        this.checkedItems = new SparseBooleanArray();
    }

    @Override
    public int getCount() {
        return listItems.size();
    }

    @Override
    public Object getItem(int i) {
        return null;
    }

    @Override
    public long getItemId(int i) {
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup viewGroup) {
        View listItem;
        LayoutInflater inflater = (LayoutInflater) mContext
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        if (convertView == null) {
            listItem = inflater.inflate(R.layout.group_layout, null);
        } else {
            listItem = convertView;
        }
        TextView tv = (TextView) listItem.findViewById(R.id.tv_item_head);
        tv.setText(listItems.get(position));
        listItem.setId(position);
        listItem.setActivated(checkedItems.get(position));
        return listItem;
    }
}

这里有什么遗漏。任何帮助将不胜感激。 请指出我的代码中没有遵守android约定或规则的任何内容，如果有的话。