二级列表

package com.example.expandlistview;


import java.util.ArrayList;
import java.util.List;


import android.os.Bundle;
import android.app.Activity;
import android.database.DataSetObserver;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.ExpandableListView.OnChildClickListener;
import android.widget.ExpandableListView.OnGroupClickListener;
import android.widget.TextView;
import android.widget.Toast;


public class MainActivity extends Activity {

//一级标题的列表
private List<String> groupList;
//二级标题的列表
    private List<List<String>> itemList;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        ExpandableListView  exlistview=(ExpandableListView) findViewById(R.id.exlistview);
       
        //初使化数据源
        initData();
      
        //设置适配器
        exlistview.setAdapter(new MyAdapter());
        
        //一级标题的点击事件
        exlistview.setOnGroupClickListener(new OnGroupClickListener() {

@Override
public boolean onGroupClick(ExpandableListView parent, View v,
int groupPosition, long id) {
Toast.makeText(MainActivity.this, "第"+groupPosition+"组被点击", 0).show();
return false;
}
});
      //二级标题的点击事件 （注意：需要将适配器中的 isChildSelectable 这个方法的返回值设置成true）
        exlistview.setOnChildClickListener(new OnChildClickListener() {

@Override
public boolean onChildClick(ExpandableListView parent, View v,
int groupPosition, int childPosition, long id) {

Toast.makeText(MainActivity.this, itemList.get(groupPosition).get(childPosition), 0).show();
return false;
}
});
        
        
    }
    
    private void initData() {
    groupList=new ArrayList<String>();
    groupList.add("我的好友");
    groupList.add("我的家人");
    groupList.add("我的同学");
   
    List<String> items=new ArrayList<String>();
    items.add("好友1");
    items.add("好友2");
   
    List<String> items1=new ArrayList<String>();
    items1.add("家人1");
    items1.add("家人2");
   
    List<String> items2=new ArrayList<String>();
    items2.add("同学1");
    items2.add("同学2");
   
    itemList=new ArrayList<List<String>>();
    itemList.add(items);
    itemList.add(items1);
    itemList.add(items2);

}




    //构建适配器  实现接口 ExpandableListAdapter--
    //还有一种构建适配器的方法是去 继承BaseExpandableListAdapter这个类
    
    //最主要是去 实现四个方法  getGroupCount、getChildrenCount、getGroupView、getChildView
    
class MyAdapter implements ExpandableListAdapter{
   
    @Override
public int getGroupCount() {
    //返回一级标题的个数
return groupList.size();
}
   
    @Override
public int getChildrenCount(int groupPosition) {
    //返回一级标题对应的二级标题的个数
return itemList.get(groupPosition).size();
}
   
    //得到一级标题的View
    @Override
public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
   
    View vv=View.inflate(MainActivity.this, R.layout.group_layout, null);
   
    TextView tv_group=(TextView)vv.findViewById(R.id.tv_group);
   
    tv_group.setText(groupList.get(groupPosition));

return vv;
}
    //得到二级标题的View
@Override
public View getChildView(int groupPosition, int childPosition,
boolean isLastChild, View convertView, ViewGroup parent) {

View itemView=View.inflate(MainActivity.this, R.layout.goup_item_layout, null);

TextView tv_group_item=(TextView)itemView.findViewById(R.id.tv_group_item);

tv_group_item.setText(itemList.get(groupPosition).get(childPosition));

return itemView;

}

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

}


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

}




@Override
public Object getGroup(int groupPosition) {
// TODO Auto-generated method stub
return null;
}


@Override
public Object getChild(int groupPosition, int childPosition) {
// TODO Auto-generated method stub
return null;
}


@Override
public long getGroupId(int groupPosition) {
// TODO Auto-generated method stub
return 0;
}


@Override
public long getChildId(int groupPosition, int childPosition) {
// TODO Auto-generated method stub
return 0;
}


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





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


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


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


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

}


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

}


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


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




    
    
}