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Android中多级列表可以使用ExpandableListView和SimpleExpandableListAdapter配合来实现，但是，SimpleExpandableListAdapter用起来挺麻烦的，不易理解，而且扩展性也不好，因此，自定义BaseExpandableListAdapter类的子类以及封装相关的操作，用起来会更加直观和方便，我把我设计的封装贴出来供新手参考吧。
首先上效果图，如图所示：
1. 首先设计多级列表的标题类
就像文件和文件夹可以统一地用File类来抽象一样，多级列表的一级标题和二级标题其实也可以用同一个基类来抽象，因此，我设计了一个基类和两个子类，GroupList，GroupListChild 和 GroupListParent，其实现如下所示：
（1） GroupList 多级列表标题的抽象基类
public abstract class GroupList { private final String mTitle; public GroupList(String title) { mTitle = title; } public String getTitle() { return mTitle; } public abstract List getChild(); public abstract int getResource(); public abstract void buildView(View v);} （2） GroupListChild 多级列表二级标题子类
public class GroupListChild extends GroupList { public GroupListChild(String title) { super(title); } @Override public int getResource() { return R.layout.grouplist_child; } @Override public List getChild() { return null; } @Override public void buildView(View v) { TextView textView = (TextView)v.findViewById(R.id.GroupListChild); textView.setText(getTitle()); } } （3） GroupListParent 多级列表一级标题子类
public class GroupListParent extends GroupList { private List mPopListChilds; public GroupListParent(String title,List childs) { super(title); mPopListChilds = childs; } @Override public int getResource() { return R.layout.grouplist_parent; } @Override public List getChild() { return mPopListChilds; } @Override public void buildView(View v) { TextView textView = (TextView)v.findViewById(R.id.GroupListParent); textView.setText(getTitle()); }} 2. 设计BaseExpandableListAdapter的子类
我设计的子类是一种通用的Adapter子类，类的实现中并不包含具体的Layout实现，所有的Layout都由GroupList的getResource和buildView来负责，因此，可以非常灵活地修改Layout的具体实现，而不用修改Adapter的代码。
public class GroupListAdapter extends BaseExpandableListAdapter { private Context mContext; private List mGroups; public GroupListAdapter(Context context, List groups) { this.mContext = context; this.mGroups = groups; } @Override public Object getChild(int groupPosition, int childPosition) { List chList = mGroups.get(groupPosition).getChild(); if( chList == null) { return null; } return chList.get(childPosition); } @Override public long getChildId(int groupPosition, int childPosition) { return childPosition; } @Override public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View view,ViewGroup parent) { GroupList child = (GroupList)getChild(groupPosition, childPosition); if( child == null) { return null; } if (view == null) { LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE); view = (RelativeLayout)inflater.inflate(child.getResource(), null); } child.buildView(view); return view; } @Override public int getChildrenCount(int groupPosition) { List chList = mGroups.get(groupPosition).getChild(); if( chList == null) { return 0; } return chList.size(); } @Override public Object getGroup(int groupPosition) { return mGroups.get(groupPosition); } @Override public int getGroupCount() { return mGroups.size(); } @Override public long getGroupId(int groupPosition) { return groupPosition; } @Override public View getGroupView(int groupPosition, boolean isLastChild, View view,ViewGroup parent) { GroupList group = (GroupList)getGroup(groupPosition); if (view == null) { LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE); view = (RelativeLayout)inflater.inflate(group.getResource(), null); } group.buildView(view); return view; } @Override public boolean hasStableIds() { return true; } @Override public boolean isChildSelectable(int arg0, int arg1) { return true; }}
3. 应用代码
为了简化，我就直接在MainActivity中使用上述封装的类来完成多级列表的功能演示，示例如下：
public class MainActivity extends Activity implements OnGroupClickListener,OnChildClickListener { private ExpandableListView mlistView; private GroupListAdapter mAdapter; private static final String[] mParentMenu = { "Book", "Video", "Audio" }; private static final String[][] mChildMenu = { { "book1", "book2", "book3", "book4" }, { "video1", "video2" }, { "audio1", "audio2", "audio3","audio4"} }; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mlistView = new ExpandableListView(this); mlistView.setOnGroupClickListener(this); mlistView.setOnChildClickListener(this); List groups = new ArrayList (); for( int i=0; i childs = new ArrayList (); for( int j=0; j 4. 相关的xml文件
（1） grouplist_child.xml 文件