Android(安卓)ExpandableListActivity 学习笔记

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：

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public class ExpandableList3 extends ExpandableListActivity {
private static final String NAME = "NAME";
private static final String IS_EVEN = "IS_EVEN";

private ExpandableListAdapter mAdapter;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

List<Map<String, String>> groupData = new ArrayList<Map<String, String>>();
List<List<Map<String, String>>> childData = new ArrayList<List<Map<String, String>>>();
for (int i = 0; i < 20; 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 < 15; 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");
}
childData.add(children);
}

// Set up our adapter
mAdapter = new SimpleExpandableListAdapter(
this,
groupData, // 存储父list的数据
android.R.layout.simple_expandable_list_item_2, //父list的现实方式
new String[] { NAME,IS_EVEN}, // 父list需要显示的数据
new int[] { android.R.id.text1,android.R.id.text2}, // 父list的数据绑定到的view
childData, //子list的数据
android.R.layout.simple_expandable_list_item_2,
new String[] { NAME, IS_EVEN },
new int[] { android.R.id.text1, android.R.id.text2 }
);
setListAdapter(mAdapter);
}

}

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：

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<?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="wrap_content"
android:orientation="vertical">

<TextView android:id="@+id/text1"
android:textSize="16sp"
android:textStyle="bold"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>

<TextView android:id="@+id/text2"
android:textSize="16sp"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>
</LinearLayout>

示例2—通过SimpleCussorTreeAdapter绑定数据：

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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：

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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 void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
menu.setHeaderTitle("Sample menu");
menu.add(0, 0, 0, R.string.expandable_list_sample_action);
}

@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;
}

}
} 来自http://blog.csdn.net/xiangyong2008/archive/2010/03/06/5351969.aspx

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