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【安卓笔记】ExpandableListView的使用
实现效果：
即可伸展的ListView
其实跟普通的ListView使用没啥区别，只是ListView改为了ExpandableListView，另外适配器由BaseAdapter也换成了BaseExpandableListAdapter。
步骤：
1.编写布局文件。
分为三个，分别是主布局，group分组布局，group item布局：
activity_main.xml:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.expandablelistviewdemo.MainActivity" >
<ExpandableListView
android:id="@+id/elv"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:divider="#000"
android:dividerHeight="2.5dp"
android:indicatorLeft="?android:attr/expandableListPreferredItemIndicatorLeft" >
</ExpandableListView>
</RelativeLayout>list_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/listTitle"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:paddingBottom="10dp"
android:paddingLeft="?android:attr/expandableListPreferredItemPaddingLeft"
android:paddingTop="10dp"
android:textColor="#A4C739" />
</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="match_parent"
android:orientation="vertical" >
<TextView
android:id="@+id/expandedListItem"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:paddingBottom="10dp"
android:paddingLeft="?android:attr/expandableListPreferredChildPaddingLeft"
android:paddingTop="10dp" />
</LinearLayout>2.编写适配器代码：package com.example.expandablelistviewdemo;
import java.util.HashMap;
import java.util.List;
import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.TextView;
public class MyExpandableListAdapter extends BaseExpandableListAdapter
{
private Context mContext;
private List<String> expandableListTitle;
private HashMap<String, List<String>> expandableListDetail;
public MyExpandableListAdapter(List<String> expandableListTitle,HashMap<String,List<String>> expandableListDetail,Context mContext)
{
this.expandableListDetail = expandableListDetail;
this.expandableListTitle = expandableListTitle;
this.mContext = mContext;
}
@Override
public int getGroupCount()//分组数
{
return this.expandableListTitle.size();
}
@Override
public int getChildrenCount(int groupPosition)//分组内的item数
{
return this.expandableListDetail.get(expandableListTitle.get(groupPosition)).size();
}
@Override
public Object getGroup(int groupPosition)//获取分组数据
{
return this.expandableListTitle.get(groupPosition);
}
@Override
public Object getChild(int groupPosition, int childPosition)//获取第几分组第几个item的数据
{
return this.expandableListDetail.get(this.expandableListTitle.get(groupPosition)).get(childPosition);
}
@Override
public long getGroupId(int groupPosition)
{
return groupPosition;
}
@Override
public long getChildId(int groupPosition, int childPosition)
{
return childPosition;
}
@Override
public boolean hasStableIds()
{
return false;
}
@Override
public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent)
{
String data = http://www.mamicode.com/this.expandableListTitle.get(groupPosition);>可以看到，适配器中有两个getView的方法，分别去构造group和child的view。
3.构造数据源package com.example.expandablelistviewdemo;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
public class ExpandableListDataPump
{
public static HashMap<String, List<String>> getData()
{
HashMap<String, List<String>> expandableListDetail = new HashMap<String, List<String>>();
List<String> technology = new ArrayList<String>();
technology.add("Beats sued for noise-cancelling tech");
technology.add("Wikipedia blocks US Congress edits");
technology.add("Google quizzed over deleted links");
technology.add("Nasa seeks aid with Earth-Mars links");
technology.add("The Good, the Bad and the Ugly");
List<String> entertainment = new ArrayList<String>();
entertainment.add("Goldfinch novel set for big screen");
entertainment.add("Anderson stellar in Streetcar");
entertainment.add("Ronstadt receives White House honour");
entertainment.add("Toronto to open with The Judge");
entertainment.add("British dancer return from Russia");
List<String> science = new ArrayList<String>();
science.add("Eggshell may act like sunblock");
science.add("Brain hub predicts negative events");
science.add("California hit by raging wildfires");
science.add("Rosetta's comet seen in close-up");
science.add("Secret of sandstone shapes revealed");
expandableListDetail.put("TECHNOLOGY NEWS", technology);
expandableListDetail.put("ENTERTAINMENT NEWS", entertainment);
expandableListDetail.put("SCIENCE & ENVIRONMENT NEWS", science);
return expandableListDetail;
}
}
4.编写主界面的代码package com.example.expandablelistviewdemo;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.ExpandableListView;
import android.widget.ExpandableListView.OnChildClickListener;
import android.widget.ExpandableListView.OnGroupCollapseListener;
import android.widget.ExpandableListView.OnGroupExpandListener;
import android.widget.Toast;
public class MainActivity extends Activity
{
private ExpandableListView elv = null;
private MyExpandableListAdapter adapter = null;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
elv = (ExpandableListView) findViewById(R.id.elv);
final HashMap<String,List<String>> itemData = http://www.mamicode.com/ExpandableListDataPump.getData();>
ok，完成。这里需要注意的是ExpandableListView有多个监听器，group收缩和伸展以及子条目点击等等，按需监听。另外，默认情况下显示的时候有个箭头，你可以通过setGroupIndicator方法设置你需要的标识。
源码地址：https://github.com/Rowandjj/ExpandableListViewDemo
【安卓笔记】ExpandableListView的使用
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