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：

　　　　　　

[java] view
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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：

　　　　

[java] view
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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：

[java] view
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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：

[java] view
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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);

}

}

[java] view
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<span style="font-size: 18px; ">adapter的代码：</span>

[java] view
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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：

[java] view
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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：

[java] view
plaincopy

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：

[java] view
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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