在ExpandableListView android中的getChildView方法的NullPointerException

Question

我正在尝试在Exapandable ListView组项中使用两个视图，当我单击其中一个项目进行扩展时，它给了我NPE。当我选择一种类型的组项时，它不会发生。

NPE

getChildView（）方法中的

txtListChild.setText（“”+ childText）行

QuestionListViewAdapter.java

public class QuestionListViewAdapter extends BaseExpandableListAdapter{

    private Context _context;
    private List<Question> _listDataHeader;
    private HashMap<String, List<String>> _listDataChild;

    public QuestionListViewAdapter(Context context, List<Question> listDataHeader,
                                 HashMap<String, List<String>> listChildData) {
        this._context = context;
        this._listDataHeader = listDataHeader;
        this._listDataChild = listChildData;
    }
    @Override
    public View getChildView(int groupPosition, final int childPosition,
                             boolean isLastChild, View convertView, ViewGroup parent) {
        View childView;
        if (convertView == null) {
            LayoutInflater infalInflater = LayoutInflater.from(_context);
            childView = infalInflater.inflate(R.layout.question_list_item_type_selection_option, null);
        }else{
            childView = convertView;
        }

        final String childText = getChild(groupPosition,childPosition).toString();

        TextView txtListChild = (TextView) childView
                .findViewById(R.id.textView_question_list_item_type_selection_option_text);

        txtListChild.setText(""+childText);
        return childView;
    }

    @Override
    public Object getChild(int groupPosition, int childPosititon) {
        return _listDataChild.get(_listDataHeader.get(groupPosition).get("title")).get(childPosititon);
    }


    @Override
    public int getChildrenCount(int groupPosition) {
        return this._listDataChild.get(this._listDataHeader.get(groupPosition).get("title"))
                .size();
    }
    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }


    @Override
    public int getGroupType(int groupPosition) {
        return Integer.valueOf(_listDataHeader.get(groupPosition).get("type").toString());
    }

    @Override
    public int getGroupTypeCount() {
        return 2;
    }

    @Override
    public Object getGroup(int groupPosition) {
        return this._listDataHeader.get(groupPosition).get("title").toString();
    }

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

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

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded,
                             View convertView, ViewGroup parent) {
        String headerTitle = (String) getGroup(groupPosition);
        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater) this._context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            switch (getGroupType(groupPosition)) {
                case 1:convertView = infalInflater.inflate(R.layout.question_list_item_type_selection, null);

                    TextView lblListHeader = (TextView) convertView
                            .findViewById(R.id.textView_Question_List_Item_Type_Selection_Question);
                    lblListHeader.setTypeface(null, Typeface.BOLD);
                    lblListHeader.setText(headerTitle);
                    break;
                case 2:convertView = infalInflater.inflate(R.layout.question_list_item_type_input_text, null);

                    EditText et_lblListHeader = (EditText)convertView.findViewById(R.id.editText_Question_List_Item_Type_Input_Text_Question);
                    //et_lblListHeader.setTypeface(BootstrapApplication.getInstance().getTypeface(1));
                    et_lblListHeader.setHint(headerTitle);
                    break;
            }
        }
        return convertView;
    }
}

question_list_item_type_selection_option.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:text="Large Text"
        android:id="@+id/textView_question_list_item_type_selection_option_text"
        android:layout_margin="5dp" />
</LinearLayout>