使用ExpandableListView和ExpandableListAdapter实现分组列表

ExpandableListView直接继承自ListView，而ExpandableListAdapter是一个超级接口，独立于Adapter接口。

ExpandableListAdapter类图：

下面的例子将ExpandableListView与SimpleExpandableListAdapter结合，实现分组列表。

先准备好三个布局文件：

主布局文件expandablelistview_activity.xml，显示ExpandableListView：

<?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:orientation="vertical" >

    <ExpandableListView
        android:id="@+id/expandableListView1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
    </ExpandableListView>

</LinearLayout>

父列表项布局文件expandable_group.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="match_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/expandable_group_textview"
        android:layout_marginLeft="30dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"/>

</LinearLayout>

子列表项布局文件expandable_child.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="match_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/expandable_child_textview"
        android:layout_marginLeft="50dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

Activity类：

package com.zzj.ui.expandablelistviewdemo;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.ExpandableListView;
import android.widget.ExpandableListView.OnChildClickListener;
import android.widget.SimpleExpandableListAdapter;
import android.widget.Toast;

import com.zzj.ui.R;

public class MainActivity extends Activity implements OnChildClickListener {
	private String[] names = { "腾讯", "百度", "阿里巴巴" };

	private String[][] childnames = { { "QQ", "微信", "手机卫士" },
			{ "百度地图", "百度视频", "PPS&奇艺" }, { "支付宝", "新浪微博", "高德地图" } };

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);

		setContentView(R.layout.expandablelistview_activity);
		ExpandableListView expandableListView = (ExpandableListView) findViewById(R.id.expandableListView1);

		List<Map<String, String>> groupData = new ArrayList<Map<String, String>>();
		List<List<Map<String, String>>> childData = new ArrayList<List<Map<String, String>>>();

		for (int i = 0; i < names.length; i++) {
			Map<String, String> map = new HashMap<String, String>();
			map.put("name", names[i]);
			groupData.add(map);

			String[] childs = childnames[i];
			List<Map<String, String>> list = new ArrayList<Map<String, String>>();
			for (int j = 0; j < childs.length; j++) {
				Map<String, String> childMap = new HashMap<String, String>();
				childMap.put("childname", childs[j]);
				list.add(childMap);
			}
			childData.add(list);
		}

		SimpleExpandableListAdapter adapter = new SimpleExpandableListAdapter(
				this, groupData, R.layout.expandable_group,
				new String[] { "name" },
				new int[] { R.id.expandable_group_textview }, childData,
				R.layout.expandable_child, new String[] { "childname" },
				new int[] { R.id.expandable_child_textview });

		expandableListView.setAdapter(adapter);
		expandableListView.setOnChildClickListener(this);
	}

	@Override
	public boolean onChildClick(ExpandableListView parent, View v,
			int groupPosition, int childPosition, long id) {
		String text = names[groupPosition] + "\r\n"
				+ childnames[groupPosition][childPosition];
		Toast.makeText(this, text, Toast.LENGTH_LONG).show();
		return true;
	}
}

父列表数据与子列表数据的顺序必须相对应。

给ExpandableListView设置adapter的时候调用的是setAdapter(ExpandableListAdapter adapter)方法，而不是setAdapter(Adapter adapter)方法。setAdapter(Adapter adapter)方法已被重写：

 @Override
    public void setAdapter(ListAdapter adapter) {
        throw new RuntimeException(
                "For ExpandableListView, use setAdapter(ExpandableListAdapter) instead of " +
                "setAdapter(ListAdapter)");
    }

该方法已不允许被调用。

以上例子使用OnChildClickListener对子列表项的点击事件进行监听。

效果图如下：

可以参照SimpleExpandableListAdapter，扩展BaseExpandableListAdapter，实现自己的ExpandableListAdapter。