Gallery 的 Demo(11)

import android.view.View; 
import android.view.ViewGroup; 
import android.view.ContextMenu.ContextMenuInfo; 
import android.widget.AbsListView; 
import android.widget.BaseExpandableListAdapter; 
import android.widget.ExpandableListAdapter; 
import android.widget.ExpandableListView; 
import android.widget.TextView; 
import android.widget.Toast; 
import android.widget.ExpandableListView.ExpandableListContextMenuInfo; 
 
// ExpandableList - 可展开/收缩列表 
// 继承 ExpandableListActivity 以实现列表的可展开/收缩的功能 
public class _ExpandableList extends ExpandableListActivity { 
     
    private ExpandableListAdapter mAdapter; 
 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
        // TODO Auto-generated method stub 
        super.onCreate(savedInstanceState); 
 
        setTitle("ExpandableList"); 
         
        mAdapter = new MyExpandableListAdapter(); 
        setListAdapter(mAdapter); 
        registerForContextMenu(this.getExpandableListView()); 
    } 
 
    // 为列表的每一项创建上下文菜单（即长按后呼出的菜单）  
    @Override 
    public void onCreateContextMenu(ContextMenu menu, View v, 
            ContextMenuInfo menuInfo) { 
        menu.setHeaderTitle("ContextMenu"); 
        menu.add(0, 0, 0, "ContextMenu"); 
    } 
 
    // 单击上下文菜单后的逻辑 
    @Override 
    public boolean onContextItemSelected(MenuItem item) { 
        ExpandableListContextMenuInfo info = (ExpandableListContextMenuInfo) item.getMenuInfo(); 
        String title = ((TextView) info.targetView).getText().toString(); 
 
        int type = ExpandableListView.getPackedPositionType(info.packedPosition); 
        if (type == ExpandableListView.PACKED_POSITION_TYPE_CHILD) { 
            int groupPos = ExpandableListView.getPackedPositionGroup(info.packedPosition);