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：
