类似于ListView，自定义ExpandableListView只需要写一个适配器类(继承自BaseExpandableListAdapter即可)：

import java.util.List;
import java.util.zip.Inflater;

import android.app.Activity;
import android.content.Context;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.TextView;
import android.widget.ExpandableListView.OnChildClickListener;
import android.widget.ExpandableListView.OnGroupClickListener;
import android.widget.LinearLayout;

public class MExpandableListViewAdapter extends BaseExpandableListAdapter{
	
	private Activity mActivity;
	private List<String> listGroups;
	private List<List<String>> listChilds;
	
	public MExpandableListViewAdapter(
			Activity mActivity, List<String> listGroups,
			List<List<String>> listChilds) {
		this.mActivity = mActivity;
		this.listGroups = listGroups;
		this.listChilds = listChilds;
	}

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

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

	@Override
	public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView,
			ViewGroup parent) {
		ChildViewHolder childViewHolder;
		View view = convertView;
		if (view ==null) {
			childViewHolder = new ChildViewHolder();
			view = LayoutInflater.from(mActivity).inflate(R.layout.list_item_detail, null);
		}else{
			childViewHolder = (ChildViewHolder) view.getTag();
		}
		TextView tView = (TextView) view.findViewById(R.id.tv_content_helper_item_list_detail);
		tView.setText(listChilds.get(groupPosition).get(0));
		view.setTag(childViewHolder);
		return view;
	}
	
	class ChildViewHolder{
		LinearLayout llytContent;
		TextView tvAnswer;
	}

	@Override
	public int getChildrenCount(int arg0) {
		return listChilds.get(arg0).size();
	}

	@Override
	public Object getGroup(int arg0) {
		return listGroups.get(arg0);
	}

	@Override
	public int getGroupCount() {
		if (listGroups!=null) {
			return listGroups.size();
		}
		return 0;
	}

	@Override
	public long getGroupId(int arg0) {
		return arg0;
	}

	@Override
	public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
		GroupViewHolder groupViewHolder;
		if (convertView==null) {
			groupViewHolder = new GroupViewHolder();
			convertView = LayoutInflater.from(mActivity).inflate(R.layout.list_item, null);
			convertView.setTag(groupViewHolder);
		}
		else{
			groupViewHolder = (GroupViewHolder) convertView.getTag();
		}
		TextView tView = (TextView) convertView.findViewById(R.id.tv_title_helper_item_list);
		tView.setText(listGroups.get(groupPosition));
		View viewArrow = convertView.findViewById(R.id.viewArrow); 
		if (isExpanded) {
			viewArrow.setBackgroundDrawable(mActivity.getResources().getDrawable(
					R.drawable.bg_arrow_round_d));
		}
		else{
			viewArrow.setBackgroundDrawable(mActivity.getResources().getDrawable(
					R.drawable.bg_arrow_round));
		}

		return convertView;
	}
	
	class GroupViewHolder{
		TextView tvQuestion;
	}

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

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

<?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="match_parent"
    android:background="@color/white"
    android:orientation="horizontal"
    android:paddingTop="2dp" >

        <TextView
            android:id="@+id/tv_title_helper_item_list"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginBottom="15dp"
            android:layout_marginLeft="15dp"
            android:layout_marginTop="15dp"
            android:layout_weight="1"
            android:textColor="@color/color_bg_index"
            android:textSize="16sp"
            android:textStyle="bold" />

        <View
            android:id="@+id/viewArrow"
            android:layout_width="30dp"
            android:layout_height="30dp"
            android:layout_gravity="center_vertical"
            android:layout_marginRight="15dp"
            android:background="@drawable/bg_arrow_round" />
</LinearLayout>

<?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="wrap_content"
        android:background="@color/color_bg"
        android:orientation="vertical"
        android:paddingRight="10dp"
        >

        <View
            android:layout_width="match_parent"
            android:layout_height="1dp"
            android:background="@drawable/bg_border" />

        <TextView
            android:id="@+id/tv_content_helper_item_list_detail"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="10dp"
            android:layout_marginLeft="15dp"
            android:layout_marginTop="10dp"
            android:textColor="@color/color_text"
            android:textSize="14sp" />
</LinearLayout>

    <ExpandableListView
        android:id="@+id/list_view_helper"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:scrollbars="none"
        android:fadingEdge="none"
        android:groupIndicator="@color/transparent"
        android:layout_weight="1"
        android:cacheColorHint="#00000000"
        android:dividerHeight="1dp"
        android:footerDividersEnabled="false" />

其中bg_arrow_round和bg_arrow_round_d分别为向右和向下的箭头：

android--自定义ExpandableListView+隐藏指示器图片+防数据显示混乱