第八课：Activity 及其子类的使用二：ExpandableListActivity

例1：使用 ExpandableListActivity 实现可展开的 Activity

public class ExpandableListActivityTest extends ExpandableListActivity{public void onCreate(Bundle savedInstanceState){super.onCreate(savedInstanceState);ExpandableListAdapter adapter = new BaseExpandableListAdapter(){int[] logos = new int[]{R.drawable.p,R.drawable.z,R.drawable.t}; private String[] armTypes = new String[]{ "神族兵种", "虫族兵种", "人族兵种"};private String[][] arms = new String[][]{{ "狂战士", "龙骑士", "黑暗圣堂", "电兵" },{ "小狗", "刺蛇", "飞龙", "自爆飞机" },{ "机枪兵", "护士MM" , "幽灵" }};//获取指定组位置、指定子列表项处的子列表项数据@Overridepublic Object getChild(int groupPosition, int childPosition){return arms[groupPosition][childPosition];}@Overridepublic long getChildId(int groupPosition, int childPosition){return childPosition;}@Overridepublic int getChildrenCount(int groupPosition){return arms[groupPosition].length;}private TextView getTextView(){AbsListView.LayoutParams lp = new AbsListView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 64);TextView textView = new TextView(ExpandableListActivityTest.this);textView.setLayoutParams(lp);textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);textView.setPadding(36, 0, 0, 0);textView.setTextSize(20);return textView;}//该方法决定每个子选项的外观@Overridepublic View getChildView(int groupPosition, int childPosition,boolean isLastChild, View convertView, ViewGroup parent){TextView textView = getTextView();textView.setText(getChild(groupPosition, childPosition).toString());return textView;}//获取指定组位置处的组数据@Overridepublic Object getGroup(int groupPosition){return armTypes[groupPosition];}@Overridepublic int getGroupCount(){return armTypes.length;}@Overridepublic long getGroupId(int groupPosition){return groupPosition;}//该方法决定每个组选项的外观@Overridepublic View getGroupView(int groupPosition, boolean isExpanded,View convertView, ViewGroup parent){LinearLayout ll = new LinearLayout(ExpandableListActivityTest.this);ll.setOrientation(0);ImageView logo = new ImageView(ExpandableListActivityTest.this);logo.setImageResource(logos[groupPosition]);ll.addView(logo);TextView textView = getTextView();textView.setText(getGroup(groupPosition).toString());ll.addView(textView);return ll;}@Overridepublic boolean isChildSelectable(int groupPosition, int childPosition){return true;}@Overridepublic boolean hasStableIds(){return true;}};// 设置该窗口显示列表setListAdapter(adapter);}}

例2：xml布局的方式使用 ExpandableListActivity

1.首先在main.xml添加ExpandableListView

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:orientation="vertical"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    >    <ExpandableListView    android:id="@id/android:list"   //ExpandableListView的ID为Android自定义，不可改变    android:layout_width="fill_parent"    android:layout_height="fill_parent"android:background="@drawable/background"/></LinearLayout>

2.为父目录创建布局文件

<?xml version="1.0" encoding="utf-8"?><LinearLayout  xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="wrap_content"  android:layout_height="wrap_content">  <TextView  android:id="@+id/parent_group"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:paddingTop="8px"  android:paddingLeft="50px"  android:paddingBottom="6px"  android:textColor="#ff00ff"  android:textStyle="bold"/></LinearLayout>

3.为子目录创建布局文件

<?xml version="1.0" encoding="utf-8"?><LinearLayout  xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:paddingLeft="20dp"  android:orientation="horizontal">  <ImageView  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:paddingLeft="20px" android:paddingTop="4dp"  android:background="@drawable/child_image"/>  <LinearLayout  android:orientation="vertical"  android:layout_width="wrap_content"  android:layout_height="wrap_content">  <TextView  android:id="@+id/child_group"  android:textSize="20sp"  android:layout_width="wrap_content"  android:layout_height="wrap_content"/>  <TextView    android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:text="地址：xx省xx市xx"/>  </LinearLayout></LinearLayout>

4.DisplayExpandableList.java

package com.yin;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import android.app.ExpandableListActivity;import android.os.Bundle;import android.widget.ExpandableListAdapter;import android.widget.ExpandableListView;import android.widget.SimpleExpandableListAdapter;public class DisplayExpandableList extends ExpandableListActivity {/** Called when the activity is first created. */@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);List<HashMap<String, String>> parent_groups = new ArrayList<HashMap<String, String>>();String[] parent_group_names = {"我的好友","初中同学","高中同学","大学同学","黑名单"};parent_groups = this.addParentItems(parent_groups, parent_group_names);List<List<HashMap<String, String>>> child_groups = new ArrayList<List<HashMap<String, String>>>();List<HashMap<String, String>> child_lists = new ArrayList<HashMap<String, String>>();child_groups = this.addChildsItems(child_groups, child_lists,"小华");/** * SimpleExpandableListAdapter的参数那是相当的多啊 * 参数   1：context   * 2：父级目录的数据 * 3：父级目录的布局文件 * 4: 夫级目录的数据来源 * 5：指定父级目录显示数据的控件 * 6：子级目录的数据 * 7：子级目录的布局文件 * 8：子级目录的数据来源 * 9：指定子级目录显示数据的控件 */SimpleExpandableListAdapter adapter = new SimpleExpandableListAdapter(this, parent_groups, R.layout.parent_layout,new String[]{"parent_group"}, new int[]{R.id.parent_group},child_groups, R.layout.child_layout, new String[]{"child_group"},new int[]{R.id.child_group});setListAdapter(adapter);}//为每个父母目录下子目录添加数据public List<List<HashMap<String, String>>> addChildsItems(List<List<HashMap<String, String>>> child_groups,List<HashMap<String, String>> child_list, String item) {child_groups = new ArrayList<List<HashMap<String, String>>>();child_list = new ArrayList<HashMap<String, String>>();HashMap<String, String> map = new HashMap<String, String>();map.put("child_group", item);child_list.add(map);child_groups.add(child_list);return child_groups;}//为父级目录分组，添加标识public List<HashMap<String, String>> addParentItems(List<HashMap<String, String>> parent_groups, String[] parent_group_names) {parent_groups = new ArrayList<HashMap<String, String>>();for(int i=0;i<parent_group_names.length;i++){HashMap<String, String> groups = new HashMap<String, String>();groups.put("parent_group", parent_group_names[i]);parent_groups.add(groups);}return parent_groups;}}

后续链接： Activity 及其子类的使用三：PreferenceActivity

源代码下载