Android ExpandableListActivity 学习笔记（转载）

An activity that displays an expandable list of items by binding to a data source implementing the ExpandableListAdapter, and exposes event handlers when the user selects an item.

  即，可扩展的list，单击某个item后，又可显示一个子list。它的数据通过绑定到ExpandableListAdapter或者ExpandableListAdapter的子类上。

示例1—通过SimpelExpandableListAdapter绑定数据：

   1. public class ExpandableList3 extends ExpandableListActivity {  
   2.     private static final String NAME = "NAME";  
   3.     private static final String IS_EVEN = "IS_EVEN";  
   4.       
   5.     private ExpandableListAdapter mAdapter;  
   6.       
   7.     @Override  
   8.     public void onCreate(Bundle savedInstanceState) {  
   9.         super.onCreate(savedInstanceState);  
  10.   
  11.         List<Map<String, String>> groupData = new ArrayList<Map<String, String>>();  
  12.         List<List<Map<String, String>>> childData = new ArrayList<List<Map<String, String>>>();  
  13.         for (int i = 0; i < 20; i++) {  
  14.             Map<String, String> curGroupMap = new HashMap<String, String>();  
  15.             groupData.add(curGroupMap);  
  16.             curGroupMap.put(NAME, "Group " + i);  
  17.             curGroupMap.put(IS_EVEN, (i % 2 == 0) ? "This group is even" : "This group is odd");  
  18.               
  19.             List<Map<String, String>> children = new ArrayList<Map<String, String>>();  
  20.             for (int j = 0; j < 15; j++) {  
  21.                 Map<String, String> curChildMap = new HashMap<String, String>();  
  22.                 children.add(curChildMap);  
  23.                 curChildMap.put(NAME, "Child " + j);  
  24.                 curChildMap.put(IS_EVEN, (j % 2 == 0) ? "This child is even" : "This child is odd");  
  25.             }  
  26.             childData.add(children);  
  27.         }  
  28.           
  29.         // Set up our adapter  
  30.         mAdapter = new SimpleExpandableListAdapter(  
  31.                 this,  
  32.                 groupData,  // 存储父list的数据  
  33.                 android.R.layout.simple_expandable_list_item_2, //父list的现实方式  
  34.                 new String[] { NAME,IS_EVEN},                    // 父list需要显示的数据  
  35.             new int[] { android.R.id.text1,android.R.id.text2}, // 父list的数据绑定到的view  
  36.                 childData,                                      //子list的数据  
  37.                 android.R.layout.simple_expandable_list_item_2,  
  38.                 new String[] { NAME, IS_EVEN },  
  39.                 new int[] { android.R.id.text1, android.R.id.text2 }  
  40.                 );  
  41.         setListAdapter(mAdapter);  
  42.     }  
  43.   
  44. }  

注意：android.R.layout.simple_expandable_list_item_1：表示只显示一个TextView的数据，即R.id.text1

          android.R.layout.simple_expandable_list_item_2：表示显示二个TextView的数据，即R.id.text1，R.id,text2

         android.R.layout.simple_expandable_list_item_2.xml(在R.layout中)文件的布局如下：

   1. <?xml version="1.0" encoding="utf-8"?>  
   2.  <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  
   3.      android:layout_width="fill_parent"  
   4.      android:layout_height="wrap_content"  
   5.      android:orientation="vertical">  
   6.    
   7.      <TextView android:id="@+id/text1"  
   8.          android:textSize="16sp"  
   9.          android:textStyle="bold"  
  10.          android:layout_width="fill_parent"  
  11.          android:layout_height="wrap_content"/>  
  12.    
  13.      <TextView android:id="@+id/text2"  
  14.          android:textSize="16sp"  
  15.          android:layout_width="fill_parent"  
  16.          android:layout_height="wrap_content"/>  
  17.  </LinearLayout>  

示例2—通过SimpleCussorTreeAdapter绑定数据：

# public class ExpandableList2 extends ExpandableListActivity {  
#     private int mGroupIdColumnIndex;   
#       
#     private String mPhoneNumberProjection[] = new String[] {  
#             People.Phones._ID, People.Phones.NUMBER  
#     };  
#   
#       
#     private ExpandableListAdapter mAdapter;  
#       
#         /*  
#          * CursorTreeAdapter's method.  
#          * Gets the Cursor for the children at the given group  
#          * /  
#     @Override  
#     public void onCreate(Bundle savedInstanceState) {  
#         super.onCreate(savedInstanceState);  
#   
#         // Query for people  
#         Cursor groupCursor = managedQuery(People.CONTENT_URI,  
#                 new String[] {People._ID, People.NAME}, null, null, null);  
#   
#         // Cache the ID column index  
#         mGroupIdColumnIndex = groupCursor.getColumnIndexOrThrow(People._ID);  
#   
#         // Set up our adapter  
#         mAdapter = new MyExpandableListAdapter(groupCursor,  
#                 this,  
#                 android.R.layout.simple_expandable_list_item_1,  
#                 android.R.layout.simple_expandable_list_item_1,  
#                 new String[] {People.NAME}, // Name for group layouts  
#                 new int[] {android.R.id.text1},  
#                 new String[] {People.NUMBER}, // Number for child layouts  
#                 new int[] {android.R.id.text1});  
#         setListAdapter(mAdapter);  
#     }  
#   
#     public class MyExpandableListAdapter extends SimpleCursorTreeAdapter {  
#   
#         public MyExpandableListAdapter(Cursor cursor, Context context, int groupLayout,  
#                 int childLayout, String[] groupFrom, int[] groupTo, String[] childrenFrom,  
#                 int[] childrenTo) {  
#             super(context, cursor, groupLayout, groupFrom, groupTo, childLayout, childrenFrom,  
#                     childrenTo);  
#         }  
#   
#   
#         @Override  
#         protected Cursor getChildrenCursor(Cursor groupCursor) {  
#             // Given the group, we return a cursor for all the children within that group   
#   
#             // Return a cursor that points to this contact's phone numbers  
#             Uri.Builder builder = People.CONTENT_URI.buildUpon();  
#             ContentUris.appendId(builder, groupCursor.getLong(mGroupIdColumnIndex));  
#             builder.appendEncodedPath(People.Phones.CONTENT_DIRECTORY);  
#             Uri phoneNumbersUri = builder.build();  
#   
#             // The returned Cursor MUST be managed by us, so we use Activity's helper  
#             // functionality to manage it for us.  
#             return managedQuery(phoneNumbersUri, mPhoneNumberProjection, null, null, null);  
#         }  
#   
#     }  
# }

示例3—通过BaseExpandableListAdapter绑定数据：

   1. public class ExpandableList1 extends ExpandableListActivity {  
   2.   
   3.     ExpandableListAdapter mAdapter;  
   4.   
   5.     @Override  
   6.     public void onCreate(Bundle savedInstanceState) {  
   7.         super.onCreate(savedInstanceState);  
   8.   
   9.         // Set up our adapter  
  10.         mAdapter = new MyExpandableListAdapter();  
  11.         setListAdapter(mAdapter);  
  12.         // register context menu, when long click the item, it will show a dialog  
  13.         registerForContextMenu(getExpandableListView());  
  14.     }  
  15.   
  16.     @Override  
  17.     public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {  
  18.         menu.setHeaderTitle("Sample menu");  
  19.         menu.add(0, 0, 0, R.string.expandable_list_sample_action);  
  20.     }  
  21.       
  22.     @Override  
  23.     public boolean onContextItemSelected(MenuItem item) {  
  24.         ExpandableListContextMenuInfo info = (ExpandableListContextMenuInfo) item.getMenuInfo();  
  25.   
  26.         String title = ((TextView) info.targetView).getText().toString();  
  27.           
  28.         int type = ExpandableListView.getPackedPositionType(info.packedPosition);  
  29.         if (type == ExpandableListView.PACKED_POSITION_TYPE_CHILD) {  
  30.             int groupPos = ExpandableListView.getPackedPositionGroup(info.packedPosition);   
  31.             int childPos = ExpandableListView.getPackedPositionChild(info.packedPosition);   
  32.             Toast.makeText(this, title + ": Child " + childPos + " clicked in group " + groupPos,  
  33.                     Toast.LENGTH_SHORT).show();  
  34.             return true;  
  35.         } else if (type == ExpandableListView.PACKED_POSITION_TYPE_GROUP) {  
  36.             int groupPos = ExpandableListView.getPackedPositionGroup(info.packedPosition);   
  37.             Toast.makeText(this, title + ": Group " + groupPos + " clicked", Toast.LENGTH_SHORT).show();  
  38.             return true;  
  39.         }  
  40.           
  41.         return false;  
  42.     }  
  43.   
  44.     /** 
  45.      * A simple adapter which maintains an ArrayList of photo resource Ids.  
  46.      * Each photo is displayed as an image. This adapter supports clearing the 
  47.      * list of photos and adding a new photo. 
  48.      * 
  49.      */  
  50.     public class MyExpandableListAdapter extends BaseExpandableListAdapter {  
  51.         // Sample data set.  children[i] contains the children (String[]) for groups[i].  
  52.         private String[] groups = { "People Names", "Dog Names", "Cat Names", "Fish Names" };  
  53.         private String[][] children = {  
  54.                 { "Arnold", "Barry", "Chuck", "David" },  
  55.                 { "Ace", "Bandit", "Cha-Cha", "Deuce" },  
  56.                 { "Fluffy", "Snuggles" },  
  57.                 { "Goldy", "Bubbles" }  
  58.         };  
  59.           
  60.         public Object getChild(int groupPosition, int childPosition) {  
  61.             return children[groupPosition][childPosition];  
  62.         }  
  63.   
  64.         public long getChildId(int groupPosition, int childPosition) {  
  65.             return childPosition;  
  66.         }  
  67.   
  68.         public int getChildrenCount(int groupPosition) {  
  69.             return children[groupPosition].length;  
  70.         }  
  71.   
  72.         public TextView getGenericView() {  
  73.             // Layout parameters for the ExpandableListView  
  74.             AbsListView.LayoutParams lp = new AbsListView.LayoutParams(  
  75.                     ViewGroup.LayoutParams.FILL_PARENT, 64);  
  76.   
  77.             TextView textView = new TextView(ExpandableList1.this);  
  78.             textView.setLayoutParams(lp);  
  79.             // Center the text vertically  
  80.             textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);  
  81.             // Set the text starting position  
  82.             textView.setPadding(36, 0, 0, 0);  
  83.             return textView;  
  84.         }  
  85.           
  86.         public View getChildView(int groupPosition, int childPosition, boolean isLastChild,  
  87.                 View convertView, ViewGroup parent) {  
  88.             TextView textView = getGenericView();  
  89.             textView.setText(getChild(groupPosition, childPosition).toString());  
  90.             return textView;  
  91.         }  
  92.   
  93.         public Object getGroup(int groupPosition) {  
  94.             return groups[groupPosition];  
  95.         }  
  96.   
  97.         public int getGroupCount() {  
  98.             return groups.length;  
  99.         }  
 100.   
 101.         public long getGroupId(int groupPosition) {  
 102.             return groupPosition;  
 103.         }  
 104.   
 105.         public View getGroupView(int groupPosition, boolean isExpanded, View convertView,  
 106.                 ViewGroup parent) {  
 107.             TextView textView = getGenericView();  
 108.             textView.setText(getGroup(groupPosition).toString());  
 109.             return textView;  
 110.         }  
 111.   
 112.         public boolean isChildSelectable(int groupPosition, int childPosition) {  
 113.             return true;  
 114.         }  
 115.   
 116.         public boolean hasStableIds() {  
 117.             return true;  
 118.         }  
 119.   
 120.     }  
 121. }