Android ExpandableListView, which one is displayed, and other hidden implementations

:
Directly run the Code [java] public class MyActivity extends Activity implements HandleClick {private ExpandableListView listView; private int lastClick =-1; // position public void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); setContentView (R. layout. main); listView = (ExpandableListView) findViewById (R. id. listView); // remove the previous arrow icon listView. setGroupIndicator (null); MyExpandAdapt Er adapter = new MyExpandAdapter (this); adapter. setHnadleClick (this); listView. setAdapter (adapter); listView. setOnGroupClickListener (new OnGroupClickListener () {public boolean onGroupClick (ExpandableListView parent, View v, int groupPosition, long id) {if (lastClick =-1) {listView. expandGroup (groupPosition);} if (lastClick! =-1 & lastClick! = GroupPosition) {listView. collapseGroup (lastClick); listView. expandGroup (groupPosition);} else if (lastClick = groupPosition) {if (listView. isGroupExpanded (groupPosition) listView. collapseGroup (groupPosition); else if (! ListView. isGroupExpanded (groupPosition) listView. expandGroup (groupPosition) ;}lastclick = groupPosition; return true ;}});} public void handleClick (int type) {Toast. makeText (MyActivity. this ,"... clicked... ", Toast. LENGTH_SHORT ). show () ;}} adapter: [java] public class MyExpandAdapter extends BaseExpandableListAdapter {private Context context; private String [] roomName = new String [] {"Room 1 ", "Room 2", "Room 3", "Room 4", "Room 5"}; private String [] peoNum = new String [] {"1323 people ", "6654", "86554", "6565", "7967"}; private String [] startTime = new String [] {"Start now ", "1 minute", "2 minutes", "3 minutes", "4 minutes"}; private HandleClick handleClick; public interface HandleClick {public void handleClick (int type );} public void setHnadleClick (HandleClick hc) {this. handleClick = hc;} public MyExpandAdapter (Context context) {this. context = context;} public boolean isChildSelectable (int groupPosition, int childPosition) {// TODO Auto-generated method stub return false;} @ Override public boolean hasStableIds () {// TODO Auto-generated method stub return false;} @ Override public View getGroupView (int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {convertView = (RelativeLayout) RelativeLayout. inflate (context, R. layout. group, null); TextView TV _roomName = (TextView) convertView. findViewById (R. id. TV _roomName); TextView TV _time = (TextView) convertView. findViewById (R. id. TV _time); TextView TV _peoNum = (TextView) convertView. findViewById (R. id. TV _peoNum); values (roomName [groupPosition]); TV _time.setText (peoNum [groupPosition]); values (startTime [groupPosition]); return convertView;} @ Override public long getGroupId (int groupPosition) {// TODO Auto-generated method stub return 0;} @ Override public int getGroupCount () {// TODO Auto-generated method stub return roomName. length ;}@ Override public Object getGroup (int groupPosition) {// TODO Auto-generated method stub return null;} @ Override public int getChildrenCount (int groupPosition) {// TODO Auto-generated method stub return 1;} @ Override public View getChildView (int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {convertView = (LinearLayout) linearLayout. inflate (context, R. layout. child, null); TextView child_startTime = (TextView) convertView. findViewById (R. id. child_startTime); TextView child_peoNum = (TextView) convertView. findViewById (R. id. child_peoNum); Button child_button = (Button) convertView. findViewById (R. id. child_button); child_startTime.setText (startTime [groupPosition]); child_peoNum.setText (peoNum [groupPosition]); listener (new OnClickListener () {public void onClick (View v) {handleClick. handleClick (1) ;}}); return convertView;} public long getChildId (int groupPosition, int childPosition) {// TODO Auto-generated method stub return 0 ;} @ Override public Object getChild (int groupPosition, int childPosition) {// TODO Auto-generated method stub return null ;}}