具有可扩展列表视图的片段

Question

我正在制作一个在滑动标签片段中使用可展开列表视图的应用。 我也在使用android-support v4.jar库。

我收到了这个错误。有人可以帮帮我吗？

PorTitulo.java

package com.android.bibliotecautpmovil;
import java.util.HashMap;
import java.util.List;
import com.android.bibliotecautpmovil.R; 
import android.content.Context;
import android.graphics.Typeface;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.*;

public class PorTitulo extends Fragment {

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle          savedInstanceState) {

    View view = inflater.inflate(R.layout.fragment_titulo, container, false);
    ExpandableListView elv = (ExpandableListView) view.findViewById(R.id.lvExp);    
    elv.setAdapter(new TabsListAdapter());  // **HERE I HAVE THE ERROR**
    return view;
}

public class TabsListAdapter extends BaseExpandableListAdapter {

    private Context _context;
    private List<String> _listDataHeader; 

    private HashMap<String, List<String>> _listDataChild;

    public TabsListAdapter(Context context, List<String> listDataHeader,
        HashMap<String, List<String>> listChildData) {
    this._context = context;
    this._listDataHeader = listDataHeader;
    this._listDataChild = listChildData;
}

    private String[] groups = { "People Names", "Dog Names", "Cat Names", "Fish Names" };

    private String[][] children = {
        { "Arnold", "Barry", "Chuck", "David" },
        { "Ace", "Bandit", "Cha-Cha", "Deuce" },
        { "Fluffy", "Snuggles" },
        { "Goldy", "Bubbles" }
    };

    @Override`enter code here`
    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 childPosititon) {
        return this._listDataChild.get(this._listDataHeader.get(groupPosition))
                .get(childPosititon);
    }

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

    //

    @Override`enter code here`
    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);
            convertView = infalInflater.inflate(R.layout.list_group, null);
        }

        TextView lblListHeader = (TextView) convertView
                .findViewById(R.id.lblListHeader);
        lblListHeader.setTypeface(null, Typeface.BOLD);
        lblListHeader.setText(headerTitle);

        return convertView;
    }

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

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

    @Override
    public View getChildView(int groupPosition, final int childPosition,
            boolean isLastChild, View convertView, ViewGroup parent) {

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

        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater) this._context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.list_item, null);
        }

        TextView txtListChild = (TextView) convertView
                .findViewById(R.id.lblListItem);

        txtListChild.setText(childText);
        return convertView;
    }   
}
}

activity_main.xml中

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:background="@drawable/fondoutp" >

        <ExpandableListView
            android:id="@+id/list"
            android:layout_height="match_parent"
            android:layout_width="match_parent"
            android:cacheColorHint="#00000000"/>   

</LinearLayout>

list_group.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="8dp" 
android:background="#000000">


<TextView
    android:id="@+id/lblListHeader"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:paddingLeft="?android:attr/expandableListPreferredItemPaddingLeft"
    android:textSize="17dp"
    android:textColor="#f9f93d" />

 </LinearLayout>

list_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="55dip"
android:orientation="vertical" >

<TextView
    android:id="@+id/lblListItem"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:textSize="17dip"
    android:paddingTop="5dp"
    android:paddingBottom="5dp"
    android:textColor="#000000"
    android:paddingLeft="?android:attr/expandableListPreferredChildPaddingLeft" />

</LinearLayout>