Android ExpandableListView的使用

Android ExpandableListView的使用

一、MainActivity要继承ExpandableListActivity。效果是当单机ListView的子项是显示另一个ListView。

public class MainActivity extends ExpandableListActivity {
	
	private static final String NAME = "NAME";
	private static final String IS_EVEN = "IS_EVEN";
	private ExpandableListAdapter eListAdapter;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		
		List<Map<String,String>> groupData = new ArrayList<Map<String,String>>();
		List<List<Map<String, String>>> childDataList = new ArrayList<List<Map<String,String>>>();
		for (int i = 0; i < 10; i++) {
			Map<String, String> curGroupMap = new HashMap<String, String>();
			groupData.add(curGroupMap);
			curGroupMap.put(NAME, "Group"+i);
			curGroupMap.put(IS_EVEN, (i%2==0)? "This group is even": "This group is odd");
			
			List<Map<String, String>> children = new ArrayList<Map<String,String>>();
			for (int j = 0; j < 8; j++) {
				Map<String, String> curChildMap = new HashMap<String, String>();
				children.add(curChildMap);
				curChildMap.put(NAME, "Child" + j);
				curChildMap.put(IS_EVEN, (j % 2 == 0) ? "This child is even" : "This child is odd" );
			}
			childDataList.add(children);
		}
		eListAdapter = new SimpleExpandableListAdapter(
				this, 
				groupData, 
				android.R.layout.simple_expandable_list_item_2,
				new String[] {NAME, IS_EVEN }, 
				new int[] { android.R.id.text1, android.R.id.text2}, 
				childDataList, 
				android.R.layout.simple_expandable_list_item_2, 
				new String[] {NAME, IS_EVEN}, 
				new int[] { android.R.id.text1, android.R.id.text2});
		
		setListAdapter(eListAdapter);
				
	}
}

代码解释

1、groupData是父数据 ，childDataList是子数据。

2、android.R.layout.simple_expandable_list_item_2表示list的实现方式

3、new String[] { NAME,IS_EVEN}list需要显示的数据。             

效果图：

也就是单机Group2时，显示Group2的数据。

二、数据源：SimpleCursorTreeAdapter的使用

显示通讯录中的姓名，单击用姓名，显示号码。前提还要分配读取通讯录的权限

 <uses-permission android:name="android.permission.READ_CONTACTS"/>

 代码如下：

public class ExpandableList2 extends ExpandableListActivity {  
    private int mGroupIdColumnIndex;   
      
    private String mPhoneNumberProjection[] = new String[] {  
            People.Phones._ID, People.Phones.NUMBER  
    };  
  
      
    private ExpandableListAdapter mAdapter;  
      

    @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);  
        }  
  
    }  

 三、通过BaseExpandableListAdapter绑定数据

1.BaseExpandableListAdapter

public class ExpandableList3 extends Activity {  
  
	private String[] groups = { "group1", "group2", "group3", "group4" };  
    private String[][] children = {  
            { "g1 item1", "g1 item2", "g1 item3", "g1 item4" },  
            { "g2 item1", "g2 item2", "g2 item3", "g2 item4" },  
            { "g3 item1", "g3 item2" },  
            { "g4 item1", "g4 item2" }  
    };  
    //ExpandableListAdapter mAdapter;  
    private ExpandableListView expandableListView;
    private TextView tView = null; 
	
    @Override  
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
  
        setContentView(R.layout.activity_main);
        
        tView = (TextView)findViewById(R.id.textView1);
        expandableListView = (ExpandableListView)findViewById(R.id.expandableListView1);
        
        ExpandableListAdapter adapter = new BaseExpandableListAdapter() {
   	
			@Override
			public boolean isChildSelectable(int groupPosition, int childPosition) {
				// TODO Auto-generated method stub
				String string = groups[groupPosition] + children[groupPosition][childPosition];
				tView.setText(string);
				return true;
			}
			
			@Override
			public boolean hasStableIds() {
				// TODO Auto-generated method stub
				return true;
			}
			
			@Override
			public View getGroupView(int groupPosition, boolean isExpanded,
					View convertView, ViewGroup parent) {
				// TODO Auto-generated method stub
				LinearLayout layout = new LinearLayout(ExpandableList3.this);
				layout.setOrientation(0);
				layout.setPadding(50, 0, 0, 0);
				ImageView imageView = new ImageView(ExpandableList3.this);
				imageView.setImageResource(R.drawable.ic_launcher);
				layout.addView(imageView);
				
				TextView textView = getTextView();
				textView.setText(getGroup(groupPosition).toString());
				layout.addView(textView);
				return layout;
			}
			
			private TextView getTextView() {
				// TODO Auto-generated method stub
				AbsListView.LayoutParams lParams = new AbsListView.LayoutParams(
						ViewGroup.LayoutParams.FILL_PARENT, 64);
				TextView textView = new TextView(ExpandableList3.this);
				textView.setLayoutParams(lParams);
				textView.setPadding(20, 0, 0, 0);
				textView.setGravity(Gravity.LEFT | Gravity.CENTER_VERTICAL);
				return textView;
			}

			@Override
			public long getGroupId(int groupPosition) {
				// TODO Auto-generated method stub
				return groupPosition;
			}
			
			@Override
			public int getGroupCount() {
				// TODO Auto-generated method stub
				return groups.length;
			}
			
			@Override
			public Object getGroup(int groupPosition) {
				// TODO Auto-generated method stub
				return groups[groupPosition];
			}
			
			@Override
			public int getChildrenCount(int groupPosition) {
				// TODO Auto-generated method stub
				return children[groupPosition].length;
			}
			
			@Override
			public View getChildView(int groupPosition, int childPosition,
					boolean isLastChild, View convertView, ViewGroup parent) {
				// TODO Auto-generated method stub
				TextView textView  = getTextView();
				textView.setText(getChild(groupPosition, childPosition).toString());
				return textView;
			}
			
			@Override
			public long getChildId(int groupPosition, int childPosition) {
				// TODO Auto-generated method stub
				return childPosition;
			}
			
			@Override
			public Object getChild(int groupPosition, int childPosition) {
				// TODO Auto-generated method stub
				return children[groupPosition][childPosition];
			}
			
			
		};
   
		expandableListView.setAdapter(adapter);
    }  
      
}

 效果图：点击子项时，显示子项的信息。

2.数据源写一个类MyExpandableListAdapter，该类继承自 BaseExpandableListAdapter。

public class ExpandableList1 extends ExpandableListActivity {  
  
    ExpandableListAdapter mAdapter;  
  
    @Override  
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
  
        // Set up our adapter  
        mAdapter = new MyExpandableListAdapter();  
        setListAdapter(mAdapter);  
        // register context menu, when long click the item, it will show a dialog  
        registerForContextMenu(getExpandableListView());  
    }  
      
    @Override  
    public boolean onContextItemSelected(MenuItem item) {  
        ExpandableListContextMenuInfo info = (ExpandableListContextMenuInfo) item.getMenuInfo();  
  
        String title = ((TextView) info.targetView).getText().toString();  
          
        int type = ExpandableListView.getPackedPositionType(info.packedPosition);  
        if (type == ExpandableListView.PACKED_POSITION_TYPE_CHILD) {  
            int groupPos = ExpandableListView.getPackedPositionGroup(info.packedPosition);   
            int childPos = ExpandableListView.getPackedPositionChild(info.packedPosition);   
            Toast.makeText(this, title + ": Child " + childPos + " clicked in group " + groupPos,  
                    Toast.LENGTH_SHORT).show();  
            return true;  
        } else if (type == ExpandableListView.PACKED_POSITION_TYPE_GROUP) {  
            int groupPos = ExpandableListView.getPackedPositionGroup(info.packedPosition);   
            Toast.makeText(this, title + ": Group " + groupPos + " clicked", Toast.LENGTH_SHORT).show();  
            return true;  
        }  
          
        return false;  
    }  
  
    /** 
     * A simple adapter which maintains an ArrayList of photo resource Ids.  
     * Each photo is displayed as an image. This adapter supports clearing the 
     * list of photos and adding a new photo. 
     * 
     */  
    public class MyExpandableListAdapter extends BaseExpandableListAdapter {  
        // Sample data set.  children[i] contains the children (String[]) for groups[i].  
        private String[] groups = { "People Names", "Dog Names", "Cat Names", "Fish Names" };  
        private String[][] children = {  
                { "Arnold", "Barry", "Chuck", "David" },  
                { "Ace", "Bandit", "Cha-Cha", "Deuce" },  
                { "Fluffy", "Snuggles" },  
                { "Goldy", "Bubbles" }  
        };  
          
        public Object getChild(int groupPosition, int childPosition) {  
            return children[groupPosition][childPosition];  
        }  
  
        public long getChildId(int groupPosition, int childPosition) {  
            return childPosition;  
        }  
  
        public int getChildrenCount(int groupPosition) {  
            return children[groupPosition].length;  
        }  
  
        public TextView getGenericView() {  
            // Layout parameters for the ExpandableListView  
            AbsListView.LayoutParams lp = new AbsListView.LayoutParams(  
                    ViewGroup.LayoutParams.FILL_PARENT, 64);  
  
            TextView textView = new TextView(ExpandableList1.this);  
            textView.setLayoutParams(lp);  
            // Center the text vertically  
            textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);  
            // Set the text starting position  
            textView.setPadding(36, 0, 0, 0);  
            return textView;  
        }  
          
        public View getChildView(int groupPosition, int childPosition, boolean isLastChild,  
                View convertView, ViewGroup parent) {  
            TextView textView = getGenericView();  
            textView.setText(getChild(groupPosition, childPosition).toString());  
            return textView;  
       }  
 
        public Object getGroup(int groupPosition) {  
            return groups[groupPosition];  
        }  
  
       public int getGroupCount() {  
           return groups.length;  
       }  
 
        public long getGroupId(int groupPosition) {  
            return groupPosition;  
        }  
  
       public View getGroupView(int groupPosition, boolean isExpanded, View convertView,  
               ViewGroup parent) {  
           TextView textView = getGenericView();  
            textView.setText(getGroup(groupPosition).toString());  
            return textView;  
        }  
  
      public boolean isChildSelectable(int groupPosition, int childPosition) {  
            return true;  
        }  
 
        public boolean hasStableIds() {  
           return true;  
        }  
  
    }  
} 

 效果图：