android ExpandableListView使用

今天給大家講講android的目錄實現方法,就像大家看到的小說目錄一樣,android 提供了ExpandableListView控件可以實現二級列表展示效果,現在給大家講講這個控件的用法,下面是XML定義：

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" android:background="#FFFFFF" > <ExpandableListView android:id="@+id/elv_journal_catalog" android:layout_height="fill_parent" android:layout_width="fill_parent" android:cacheColorHint="#FFFFFF" /> </LinearLayout>

這代碼很簡單,和寫listView的方法差不多,接下來是ExpandableListView在activity中的代碼：

private ExpandableListView elv_journal_catalog; private List<List<Article>> childrenObj; private JournalCatalogListAdapter adapter; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.journal_catalog); init(); elv_journal_catalog.setGroupIndicator(null); elv_journal_catalog.setDivider(null); loadData(); } private void init() { elv_journal_catalog = (ExpandableListView) findViewById(R.id.elv_journal_catalog); elv_journal_catalog.setOnChildClickListener(listener); } private void loadData() { Message msg = handler.obtainMessage(); msg.what = 1; msg.sendToTarget(); childrenObj = new ArrayList<List<Article>>(); new Thread() { @Override public void run() { if (!isLoading) { queryArticleList(); } else { queryArticleListFromSqlite(); } } }.start(); adapter = new JournalCatalogListAdapter(this, childrenObj); elv_journal_catalog.setAdapter(adapter); }

ExpandableListView展示數據的時候默認是每個模塊下的列表項是閉合狀態的，如果要實現初始化的時候就展開可以通過ExpandableListView.expandGroup(location)方法來實現，而且每個父級列表項左邊會出現一個系統自帶的圖標，這個圖標是用來表示列表展開和閉合的狀態的，如果不顯示或者要替換這個圖標可以用ExpandableListView.setGroupIndicator(Drawable icon)方法來實現,我這裏是直接是沒有使用任何圖標,你也可以在adapter中自己在xml中定義自己的圖標.

ExpandableListView填充數據需要是二級菜單的模式所以數據結構大家可以根據項目情況而定，我這裏由於標題是定死的所以只傳的每個標題下的數據，下面是JournalCatalogListAdapter的代碼：

public class JournalCatalogListAdapter extends BaseExpandableListAdapter { private LayoutInflater inflater; private String[] parent = new String[] { "美顏美體", "潮流單品", "娛樂八卦", "情感", "觀點", "健康生活" }; private List<List<Article>> clildren = new ArrayList<List<Article>>(); public JournalCatalogListAdapter(Context context, List<List<Article>> clildren) { this.clildren = clildren; inflater = LayoutInflater.from(context); } @Override public Object getChild(int groupPosition, int childPosition) { return clildren.get(groupPosition).get(childPosition); } @Override public long getChildId(int groupPosition, int childPosition) { return childPosition; } @Override public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) { if (convertView == null) { convertView = inflater.inflate( R.layout.journal_catalog_list_item_content, null); } TextView textView = (TextView) convertView .findViewById(R.id.tv_journal_catalog_list_item_content); Article a = (Article) getChild(groupPosition, childPosition); textView.setText(a.getTitle()); return convertView; } @Override public int getChildrenCount(int groupPosition) { return clildren.get(groupPosition).size(); } @Override public Object getGroup(int groupPosition) { return parent[groupPosition]; } @Override public int getGroupCount() { return parent.length; } @Override public long getGroupId(int groupPosition) { return groupPosition; } @Override public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) { if (convertView == null) { convertView = inflater.inflate( R.layout.journal_catalog_list_item_title, null); } TextView textView = (TextView) convertView .findViewById(R.id.tv_journal_catalog_list_item_title); String title = String.valueOf(getGroup(groupPosition)); textView.setText(title); convertView.setOnClickListener(null); return convertView; } @Override public boolean hasStableIds() { return true; } @Override public boolean isChildSelectable(int groupPosition, int childPosition) { return true; } }