Android中可展开的列表组件(ExpandableListView)的使用

可展开的列表组件(ExpandableListView)是ListView的子类，它在普通ListView的基础上进行了扩展，把列表项分为几组，每组又可包含多个列表项。ExpandableListView和ListView的用法非常相似，只是列表项应该由ExpandableAdapter提供，下表给出了它所支持的额外XML属性：



下面通过一个简单实例来演示ExpandableListView的使用，需要在组列表和子列表添加图片等组件就自行添加，代码如下：

Activity：

package com.lovo;

import android.app.Activity;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;

public class MainActivity extends Activity {

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		// 创建一个可展开的列表组件ExpandableListAdapter对象
		ExpandableListAdapter adapter = new BaseExpandableListAdapter() {
			// 添加图片
			// int[] logos = new int[] { R.drawable.image1,
			// R.drawable.image2, R.drawable.image2 };
			// 每一个列表的字符数组
			private String[] roleTypes = new String[] { "圣职者", "神枪手", "鬼剑士" };
			// 每个列表下面的子列表字符数组
			private String[][] roles = new String[][] {
					{ "蓝拳", "驱魔", "圣骑士", "复仇者" }, { "漫游", "大枪", "弹药", "机械" },
					{ "剑魂", "红眼", "阿修罗", "鬼泣" } };

			@Override
			public boolean isChildSelectable(int groupPosition,
					int childPosition) {

				return true;
			}

			@Override
			public boolean hasStableIds() {

				return true;
			}

			// 构建每个父列表组件
			@Override
			public View getGroupView(int groupPosition, boolean isExpanded,
					View convertView, ViewGroup parent) {
				// 创建一个LinearLayout对象
				LinearLayout ll = new LinearLayout(MainActivity.this);
				ll.setOrientation(0);
				// ImageView logo = new ImageView(MainActivity.this);
				// // logo.setImageResource(logos[groupPosition]);
				// ll.addView(logo);
				TextView textView = getTextView();
				// 根据groupPosition取roleTypes对应文本作为textView显示的文本内容
				textView.setText(getGroup(groupPosition).toString());
				ll.addView(textView);
				return ll;
			}

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

			@Override
			public int getGroupCount() {

				return roleTypes.length;
			}

			@Override
			public Object getGroup(int groupPosition) {

				return roleTypes[groupPosition];
			}

			@Override
			public int getChildrenCount(int groupPosition) {

				return roles[groupPosition].length;
			}

			/**
			 * 在MainActivity里创建TextView组件
			 * 
			 * @return TextView
			 */
			private TextView getTextView() {
				AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
						ViewGroup.LayoutParams.MATCH_PARENT, 64);
				TextView textView = new TextView(MainActivity.this);
				textView.setLayoutParams(lp);
				textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
				textView.setPadding(36, 0, 0, 0);
				textView.setTextSize(20);
				return textView;
			}

			// 构建子列表的数据
			@Override
			public View getChildView(int groupPosition, int childPosition,
					boolean isLastChild, View convertView, ViewGroup parent) {
				TextView textView = getTextView();
				// 根据groupPosition和childPosition取roles中对应文本作为textView显示的内容
				textView.setText(getChild(groupPosition, childPosition)
						.toString());
				return textView;
			}

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

				return childPosition;
			}

			@Override
			public Object getChild(int groupPosition, int childPosition) {

				return roles[groupPosition][childPosition];
			}
		};
		// 获得ExpandableListView对象
		ExpandableListView expandableListView = (ExpandableListView) findViewById(R.id.list);
		// 为ExpandableListView对象设置适配器
		expandableListView.setAdapter(adapter);
	}
}

布局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" >

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

</LinearLayout>

附上图片效果：





展开子列表：