android ExpandableListView (可扩展ListView)

ExpandableListView是listView的子类(效果类似于QQ好友界面的分组)

与Adapter类似，实现 ExpandableListView由如下三种常用方法

1.扩展BaseExpandableListAdapter实现ExpandableListAdapter

2.使用SimpleExpandableListAdapter将两个List集合包装秤ExpandableListAdapter

3.使用SimpleCursorTreeAdapter将Cursor中的数据包装成SimpleCursorTreeAdapter

<span style="font-size:14px;">public class ExpandableListViewTest extends Activity {
      ExpandableListView expandableListView;
       int img [] = new int[] { R.drawable.ic_launcher, R.drawable.ic_launcher , R.drawable.ic_launcher,
                  R.drawable. ic_launcher, R.drawable.ic_launcher };
       private String name [] = new String[] { "张三", "李四" , "王五" , "赵六" , "孙七" };
       private String action [][] = new String[][] { { "洼地", "除草" , "施肥" },
                  { "洼地", "除草" , "施肥" }, { "洼地", "除草", "施肥" }, { "洼地" , "除草" , "施肥" },
                  { "洼地", "除草" , "施肥" } };

       @Override
       protected void onCreate(Bundle savedInstanceState) {
             // TODO Auto-generated method stub
             super.onCreate(savedInstanceState);
            setContentView(R.layout. activity_expandable_listview);
            ExpandableListAdapter adapter = new ExpandableListAdapter() {
                   @Override
                   public long getCombinedGroupId(long groupId) {
                         // TODO Auto-generated method stub
                         return 0;
                  }

                   @Override
                   public boolean areAllItemsEnabled() {
                         // TODO Auto-generated method stub
                         return false ;
                  }

                   @Override
                   public long getCombinedChildId(long groupId, long childId) {
                         // TODO Auto-generated method stub
                         return 0;
                  }

                   @Override
                   public void unregisterDataSetObserver(DataSetObserver observer) {
                         // TODO Auto-generated method stub

                  }

                   @Override
                   public void registerDataSetObserver(DataSetObserver observer) {
                         // TODO Auto-generated method stub

                  }

                   @Override
                   public void onGroupExpanded(int groupPosition) {
                         // TODO Auto-generated method stub

                  }

                   @Override
                   public void onGroupCollapsed(int groupPosition) {
                         // TODO Auto-generated method stub

                  }

                   @Override
                   public boolean isEmpty() {
                         // TODO Auto-generated method stub
                         return false ;
                  }

                   //此处改为true
                   @Override
                   public boolean isChildSelectable(int groupPosition,
                               int childPosition) {
                         // TODO Auto-generated method stub
                         return true ;
                  }
                   //此处改为true
                   @Override
                   public boolean hasStableIds() {
                         // TODO Auto-generated method stub
                         return true ;
                  }

                   @Override
                   public View getGroupView(int groupPosition, boolean isExpanded,
                              View convertView, ViewGroup parent) {
                         // TODO Auto-generated method stub
                        LinearLayout layout = new LinearLayout(ExpandableListViewTest.this );
                        layout.setOrientation(LinearLayout. HORIZONTAL);
                        ImageView view = new ImageView(ExpandableListViewTest.this );
                        view.setImageResource( img[groupPosition]);//根据getGroupId返回的groupPosition来获取图片的ID
                        layout.addView(view);
                        TextView text = new TextView(ExpandableListViewTest.this );
                        text.setTextSize(20);
                        text.setText(getGroup(groupPosition).toString()); //根据getGroup()方法来获取每一个text数据
                        layout.addView(text);               
                         return layout;
                  }
             
                   @Override
                   public long getGroupId(int groupPosition) {
                         // TODO Auto-generated method stub
                         return groupPosition;
                  }
            //返回父类数组的长度
                   @Override
                   public int getGroupCount() {
                         // TODO Auto-generated method stub
                         return name .length ;
                  }
           //返回父类数组的每一个对象
                   @Override
                   public Object getGroup(int groupPosition) {
                         // TODO Auto-generated method stub
                         return name [groupPosition];
                  }
                //返回每一组子选项数组的长度
                   @Override
                   public int getChildrenCount(int groupPosition) {
                         // TODO Auto-generated method stub
                         return action [groupPosition].length;
                  }
            //返回的text作为子列表的每一列的text
                   @Override
                   public View getChildView(int groupPosition, int childPosition,
                               boolean isLastChild, View convertView, ViewGroup parent) {
                         // TODO Auto-generated method stub
                        TextView text = new TextView(ExpandableListViewTest.this );
                        text.setTextSize(20);
                        text.setText(getChild(groupPosition, childPosition).toString());
                         return text;
                  }
             //返回子列表的id
                   @Override
                   public long getChildId(int groupPosition, int childPosition) {
                         // TODO Auto-generated method stub
                         return childPosition;
                  }
             //从数组获取子列表的每一个数据
                   @Override
                   public Object getChild(int groupPosition, int childPosition) {
                         // TODO Auto-generated method stub
                         return action [groupPosition][childPosition];
                  }

            };
             expandableListView = (ExpandableListView) findViewById(R.id.expandable );
             expandableListView.setAdapter(adapter);
      }

}
</span>