expandablelistview学习--在listView里面嵌套GridView

            在网上看到一个例子，讲android中的expandablelistview，是一种可以扩展的listview，就是那种点击一下可以扩展出子项，再点一下收缩回去的显示list。因为需要查看一堆文件的目录结构，就使用了expandablelist以便于直观地看到结构形式。
顶层是group，第二层是child。实现ExpandableListView至少需要下面两个类。

        一、ExpandableListView
　　　　一个垂直滚动的显示两个级别（Child,Group）列表项的视图，列表项来自ExpandableListAdapter 。组可以单独展开。
　　其所用到的重要方法如下：
　　　　　　

            expandGroup(int groupPos) :在分组列表视图中展开一组，
　　　　　　setSelectedGroup(int groupPosition) ：设置选择指定的组。
　　　　　　setSelectedChild(int groupPosition, int childPosition, boolean shouldExpandGroup) ：设置选择指定的子项。
　　　　　　getPackedPositionGroup(long packedPosition) ：返回所选择的组
　　　　　　getPackedPositionForChild(int groupPosition, int childPosition) ：返回所选择的子项
　　　　　　getPackedPositionType(long packedPosition) ：返回所选择项的类型（Child,Group）
　　　　　　isGroupExpanded(int groupPosition) :判断此组是否展开

       

  二、ExpandableListAdapter
　　　　一个接口，将基础数据链接到一个ExpandableListView。此接口的实施将提供访问Child的数据（由组分类），并实例化的Child和Group。
　　其里面重要方法：
　　　　

getChildId(int groupPosition, int childPosition) 获取与在给定组给予孩子相关的数据。
　　　　getChildrenCount(int groupPosition) 返回在指定Group的Child数目。
		getChildView() 获取子视图（就是二级视图）
	    getChildView()获取父视图

当我们想做到自己的打开或者关闭的标记时，可以先设置一个selector.xml，然后再用ExpandableListView的实例去调用setGroupIndicator(this.getResources().getDrawable(R.drawable.expand_list_selector));  这样就可以了。

下面就看下例子：

这个代码好像也是在eoe上下载下来的，具体也记不太清楚了，先看下效果图：

先给下代码，人家写的，咱们学习下：

public class ListViewActivity extends Activity
{
	ExpandableListView expandableListView;

	ListViewAdapter treeViewAdapter;

	public String[] groups = { "列表1", "列表2", "列表3" };

	public String[][] child = { { "" }, { "" }, { "", "" } };

	public void onCreate(Bundle savedInstanceState)
	{
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		treeViewAdapter = new ListViewAdapter(this,
				ListViewAdapter.PaddingLeft >> 1);
		expandableListView = (ExpandableListView) this
		.findViewById(R.id.expandableListView);

		List<ListViewAdapter.TreeNode> treeNode = treeViewAdapter.GetTreeNode();
		for (int i = 0; i < groups.length; i++)
		{
			ListViewAdapter.TreeNode node = new ListViewAdapter.TreeNode();
			node.parent = groups[i];
			for (int ii = 0; ii < child[i].length; ii++)
			{
				node.childs.add(child[i][ii]);
			}
			treeNode.add(node);
		}

		treeViewAdapter.UpdateTreeNode(treeNode);
		expandableListView.setAdapter(treeViewAdapter);
	}

	
}

GridView的定义：

class MyGridView extends GridView
	{
		public MyGridView(android.content.Context context,
				android.util.AttributeSet attrs)
		{
			super(context, attrs);
		}

		/**
		 * 设置不滚动
		 */
		public void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
		{
			int expandSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2,
			MeasureSpec.AT_MOST);
			super.onMeasure(widthMeasureSpec, expandSpec);
		}
	}

adapter的代码：

public class ListViewAdapter extends BaseExpandableListAdapter implements
		OnItemClickListener
{
	public static final int ItemHeight = 48;// 每项的高度
	public static final int PaddingLeft = 36;// 每项的高度
	private int myPaddingLeft = 0;
	private MyGridView toolbarGrid;
	private String menu_toolbar_name_array[] = { "存储卡", "我的下载", "图书导入", "系统备份",
			"系统恢复", "清除全部", "在线升级", "快速入门", "关于开卷", "退出系统", "在线升级", "快速入门",
			"关于开卷", "退出系统", "关于开卷", "退出系统", "关于开卷", "退出系统", "关于开卷", "退出系统" };
	private int menu_toolbar_image_array[] = { R.drawable.icon_sdcard,
			R.drawable.icon_sdcard, R.drawable.icon_sdcard,
			R.drawable.icon_sdcard, R.drawable.icon_sdcard,
			R.drawable.icon_sdcard, R.drawable.icon_sdcard,
			R.drawable.icon_sdcard, R.drawable.icon_sdcard,
			R.drawable.icon_sdcard, R.drawable.icon_sdcard,
			R.drawable.icon_sdcard, R.drawable.icon_sdcard,
			R.drawable.icon_sdcard, R.drawable.icon_sdcard,
			R.drawable.icon_sdcard, R.drawable.icon_sdcard,
			R.drawable.icon_sdcard, R.drawable.icon_sdcard,
			R.drawable.icon_sdcard };

	private List<TreeNode> treeNodes = new ArrayList<TreeNode>();
	private Context parentContext;
	private LayoutInflater layoutInflater;
	static public class TreeNode
	{
		Object parent;
		List<Object> childs = new ArrayList<Object>();
	}

	public ListViewAdapter(Context view, int myPaddingLeft)
	{
		parentContext = view;
		this.myPaddingLeft = myPaddingLeft;
	}

	public List<TreeNode> GetTreeNode()
	{
		return treeNodes;
	}

	public void UpdateTreeNode(List<TreeNode> nodes)
	{
		treeNodes = nodes;
	}

	public void RemoveAll()
	{
		treeNodes.clear();
	}

	public Object getChild(int groupPosition, int childPosition)
	{
		return treeNodes.get(groupPosition).childs.get(childPosition);
	}

	public int getChildrenCount(int groupPosition)
	{
		return treeNodes.get(groupPosition).childs.size();
	}

	static public TextView getTextView(Context context)
	{
		AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
				ViewGroup.LayoutParams.FILL_PARENT, ItemHeight);

		TextView textView = new TextView(context);
		textView.setLayoutParams(lp);
		textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
		return textView;
	}

	/**
	 * 可自定义ExpandableListView
	 */
	public View getChildView(int groupPosition, int childPosition,
			boolean isLastChild, View convertView, ViewGroup parent)
	{
		if (convertView == null)
		{
			layoutInflater = (LayoutInflater) parentContext
					.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
			convertView = layoutInflater.inflate(R.layout.view, null);

			toolbarGrid = (MyGridView) convertView
					.findViewById(R.id.GridView_toolbar);
			toolbarGrid.setNumColumns(4);// 设置每行列数
			toolbarGrid.setGravity(Gravity.CENTER);// 位置居中
			toolbarGrid.setHorizontalSpacing(10);// 水平间隔
			toolbarGrid.setAdapter(getMenuAdapter(menu_toolbar_name_array,
					menu_toolbar_image_array));// 设置菜单Adapter
			toolbarGrid.setOnItemClickListener(this);

		}
		return convertView;
	}

	/**
	 * 可自定义list
	 */
	public View getGroupView(int groupPosition, boolean isExpanded,
			View convertView, ViewGroup parent)
	{
		TextView textView = getTextView(this.parentContext);
		textView.setText(getGroup(groupPosition).toString());
		textView.setPadding(myPaddingLeft + PaddingLeft, 0, 0, 0);
		return textView;
	}

	public long getChildId(int groupPosition, int childPosition)
	{
		return childPosition;
	}

	public Object getGroup(int groupPosition)
	{
		return treeNodes.get(groupPosition).parent;
	}

	public int getGroupCount()
	{
		return treeNodes.size();
	}

	public long getGroupId(int groupPosition)
	{
		return groupPosition;
	}

	public boolean isChildSelectable(int groupPosition, int childPosition)
	{
		return true;
	}

	public boolean hasStableIds()
	{
		return true;
	}

	/**
	 * 构造菜单Adapter
	 * 
	 * @param menuNameArray
	 *            名称
	 * @param imageResourceArray
	 *            图片
	 * @return SimpleAdapter
	 */
	private SimpleAdapter getMenuAdapter(String[] menuNameArray,
			int[] imageResourceArray)
	{
		ArrayList<HashMap<String, Object>> data = new ArrayList<HashMap<String, Object>>();
		for (int i = 0; i < menuNameArray.length; i++)
		{
			HashMap<String, Object> map = new HashMap<String, Object>();
			map.put("itemImage", imageResourceArray[i]);
			map.put("itemText", menuNameArray[i]);
			data.add(map);
		}
		SimpleAdapter simperAdapter = new SimpleAdapter(parentContext, data,
				R.layout.item_menu, new String[] { "itemImage", "itemText" },
				new int[] { R.id.item_image, R.id.item_text });
		return simperAdapter;
	}

	@Override
	public void onItemClick(AdapterView<?> parent, View view, int position,
			long id)
	{
		Toast.makeText(parentContext, "当前选中的是:" + position, Toast.LENGTH_SHORT)
				.show();

	}
}

里面比较简单的是listView，比较难的就是嵌套GridView吧!
定义文字和图片：

private String menu_toolbar_name_array[] = { "存储卡", "我的下载", "图书导入", "系统备份",
			"系统恢复", "清除全部", "在线升级", "快速入门", "关于开卷", "退出系统", "在线升级", "快速入门",
			"关于开卷", "退出系统", "关于开卷", "退出系统", "关于开卷", "退出系统", "关于开卷", "退出系统" };
	private int menu_toolbar_image_array[] = { R.drawable.icon_sdcard,
			R.drawable.icon_sdcard, R.drawable.icon_sdcard,
			R.drawable.icon_sdcard, R.drawable.icon_sdcard,
			R.drawable.icon_sdcard, R.drawable.icon_sdcard,
			R.drawable.icon_sdcard, R.drawable.icon_sdcard,
			R.drawable.icon_sdcard, R.drawable.icon_sdcard,
			R.drawable.icon_sdcard, R.drawable.icon_sdcard,
			R.drawable.icon_sdcard, R.drawable.icon_sdcard,
			R.drawable.icon_sdcard, R.drawable.icon_sdcard,
			R.drawable.icon_sdcard, R.drawable.icon_sdcard,
			R.drawable.icon_sdcard };

里面很重要的是那个node,一定要看理解：

public List<TreeNode> GetTreeNode()
	{
		return treeNodes;
	}

	public void UpdateTreeNode(List<TreeNode> nodes)
	{
		treeNodes = nodes;
	}

	public void RemoveAll()
	{
		treeNodes.clear();
	}

	public Object getChild(int groupPosition, int childPosition)
	{
		return treeNodes.get(groupPosition).childs.get(childPosition);
	}

	public int getChildrenCount(int groupPosition)
	{
		return treeNodes.get(groupPosition).childs.size();
	}
	
	public Object getGroup(int groupPosition)
	{
		return treeNodes.get(groupPosition).parent;
	}

	public int getGroupCount()
	{
		return treeNodes.size();
	}

adapter也挺简单：

private SimpleAdapter getMenuAdapter(String[] menuNameArray,
			int[] imageResourceArray)
	{
		ArrayList<HashMap<String, Object>> data = new ArrayList<HashMap<String, Object>>();
		for (int i = 0; i < menuNameArray.length; i++)
		{
			HashMap<String, Object> map = new HashMap<String, Object>();
			map.put("itemImage", imageResourceArray[i]);
			map.put("itemText", menuNameArray[i]);
			data.add(map);
		}
		SimpleAdapter simperAdapter = new SimpleAdapter(parentContext, data,
				R.layout.item_menu, new String[] { "itemImage", "itemText" },
				new int[] { R.id.item_image, R.id.item_text });
		return simperAdapter;
	}

代码下载地址如下：http://download.csdn.net/detail/aomandeshangxiao/3986353
网上还有其他例子，
可以一并学习下：Android自定义ExpandableListView用户界面
ViewAndroid版手风琴（ExpandableListView）
ExpandableListView使用及数据更新
用ExpandableListView实现类似QQ好友列表