Android ExpandableListActivity 学习笔记

ExpandableListActivity:

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：

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：

示例2—通过SimpleCussorTreeAdapter绑定数据：

示例3—通过BaseExpandableListAdapter绑定数据：

publicclassExpandableList1extendsExpandableListActivity{

ExpandableListAdaptermAdapter;

@Override
publicvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);

//Setupouradapter
mAdapter=newMyExpandableListAdapter();
setListAdapter(mAdapter);
//registercontextmenu,whenlongclicktheitem,itwillshowadialog
registerForContextMenu(getExpandableListView());
}

@Override
publicvoidonCreateContextMenu(ContextMenumenu,Viewv,ContextMenuInfomenuInfo){
menu.setHeaderTitle("Samplemenu");
menu.add(0,0,0,R.string.expandable_list_sample_action);
}

@Override
publicbooleanonContextItemSelected(MenuItemitem){
ExpandableListContextMenuInfoinfo=(ExpandableListContextMenuInfo)item.getMenuInfo();

Stringtitle=((TextView)info.targetView).getText().toString();

inttype=ExpandableListView.getPackedPositionType(info.packedPosition);
if(type==ExpandableListView.PACKED_POSITION_TYPE_CHILD){
intgroupPos=ExpandableListView.getPackedPositionGroup(info.packedPosition);
intchildPos=ExpandableListView.getPackedPositionChild(info.packedPosition);
Toast.makeText(this,title+":Child"+childPos+"clickedingroup"+groupPos,
Toast.LENGTH_SHORT).show();
returntrue;
}elseif(type==ExpandableListView.PACKED_POSITION_TYPE_GROUP){
intgroupPos=ExpandableListView.getPackedPositionGroup(info.packedPosition);
Toast.makeText(this,title+":Group"+groupPos+"clicked",Toast.LENGTH_SHORT).show();
returntrue;
}

returnfalse;
}

/**
*AsimpleadapterwhichmaintainsanArrayListofphotoresourceIds.
*Eachphotoisdisplayedasanimage.Thisadaptersupportsclearingthe
*listofphotosandaddinganewphoto.
*
*/
publicclassMyExpandableListAdapterextendsBaseExpandableListAdapter{
//Sampledataset.children[i]containsthechildren(String[])forgroups[i].
privateString[]groups={"PeopleNames","DogNames","CatNames","FishNames"};
privateString[][]children={
{"Arnold","Barry","Chuck","David"},
{"Ace","Bandit","Cha-Cha","Deuce"},
{"Fluffy","Snuggles"},
{"Goldy","Bubbles"}
};

publicObjectgetChild(intgroupPosition,intchildPosition){
returnchildren[groupPosition][childPosition];
}

publiclonggetChildId(intgroupPosition,intchildPosition){
returnchildPosition;
}

publicintgetChildrenCount(intgroupPosition){
returnchildren[groupPosition].length;
}

publicTextViewgetGenericView(){
//LayoutparametersfortheExpandableListView
AbsListView.LayoutParamslp=newAbsListView.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT,64);

TextViewtextView=newTextView(ExpandableList1.this);
textView.setLayoutParams(lp);
//Centerthetextvertically
textView.setGravity(Gravity.CENTER_VERTICAL|Gravity.LEFT);
//Setthetextstartingposition
textView.setPadding(36,0,0,0);
returntextView;
}

publicViewgetChildView(intgroupPosition,intchildPosition,booleanisLastChild,
ViewconvertView,ViewGroupparent){
TextViewtextView=getGenericView();
textView.setText(getChild(groupPosition,childPosition).toString());
returntextView;
}

publicObjectgetGroup(intgroupPosition){
returngroups[groupPosition];
}

publicintgetGroupCount(){
returngroups.length;
}

publiclonggetGroupId(intgroupPosition){
returngroupPosition;
}

publicViewgetGroupView(intgroupPosition,booleanisExpanded,ViewconvertView,
ViewGroupparent){
TextViewtextView=getGenericView();
textView.setText(getGroup(groupPosition).toString());
returntextView;
}

publicbooleanisChildSelectable(intgroupPosition,intchildPosition){
returntrue;
}

publicbooleanhasStableIds(){
returntrue;
}

}
}

publicclassExpandableList2extendsExpandableListActivity{
privateintmGroupIdColumnIndex;

privateStringmPhoneNumberProjection[]=newString[]{
People.Phones._ID,People.Phones.NUMBER
};


privateExpandableListAdaptermAdapter;

/*
*CursorTreeAdapter'smethod.
*GetstheCursorforthechildrenatthegivengroup
*/
@Override
publicvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);

//Queryforpeople
CursorgroupCursor=managedQuery(People.CONTENT_URI,
newString[]{People._ID,People.NAME},null,null,null);

//CachetheIDcolumnindex
mGroupIdColumnIndex=groupCursor.getColumnIndexOrThrow(People._ID);

//Setupouradapter
mAdapter=newMyExpandableListAdapter(groupCursor,
this,
android.R.layout.simple_expandable_list_item_1,
android.R.layout.simple_expandable_list_item_1,
newString[]{People.NAME},//Nameforgrouplayouts
newint[]{android.R.id.text1},
newString[]{People.NUMBER},//Numberforchildlayouts
newint[]{android.R.id.text1});
setListAdapter(mAdapter);
}

publicclassMyExpandableListAdapterextendsSimpleCursorTreeAdapter{

publicMyExpandableListAdapter(Cursorcursor,Contextcontext,intgroupLayout,
intchildLayout,String[]groupFrom,int[]groupTo,String[]childrenFrom,
int[]childrenTo){
super(context,cursor,groupLayout,groupFrom,groupTo,childLayout,childrenFrom,
childrenTo);
}


@Override
protectedCursorgetChildrenCursor(CursorgroupCursor){
//Giventhegroup,wereturnacursorforallthechildrenwithinthatgroup

//Returnacursorthatpointstothiscontact'sphonenumbers
Uri.Builderbuilder=People.CONTENT_URI.buildUpon();
ContentUris.appendId(builder,groupCursor.getLong(mGroupIdColumnIndex));
builder.appendEncodedPath(People.Phones.CONTENT_DIRECTORY);
UriphoneNumbersUri=builder.build();

//ThereturnedCursorMUSTbemanagedbyus,soweuseActivity'shelper
//functionalitytomanageitforus.
returnmanagedQuery(phoneNumbersUri,mPhoneNumberProjection,null,null,null);
}

}
}

<?xmlversion="1.0"encoding="utf-8"?>
<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical">

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

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

publicclassExpandableList3extendsExpandableListActivity{
privatestaticfinalStringNAME="NAME";
privatestaticfinalStringIS_EVEN="IS_EVEN";

privateExpandableListAdaptermAdapter;

@Override
publicvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);

List<Map<String,String>>groupData=newArrayList<Map<String,String>>();
List<List<Map<String,String>>>childData=newArrayList<List<Map<String,String>>>();
for(inti=0;i<20;i++){
Map<String,String>curGroupMap=newHashMap<String,String>();
groupData.add(curGroupMap);
curGroupMap.put(NAME,"Group"+i);
curGroupMap.put(IS_EVEN,(i%2==0)?"Thisgroupiseven":"Thisgroupisodd");

List<Map<String,String>>children=newArrayList<Map<String,String>>();
for(intj=0;j<15;j++){
Map<String,String>curChildMap=newHashMap<String,String>();
children.add(curChildMap);
curChildMap.put(NAME,"Child"+j);
curChildMap.put(IS_EVEN,(j%2==0)?"Thischildiseven":"Thischildisodd");
}
childData.add(children);
}

//Setupouradapter
mAdapter=newSimpleExpandableListAdapter(
this,
groupData,//存储父list的数据
android.R.layout.simple_expandable_list_item_2,//父list的现实方式
newString[]{NAME,IS_EVEN},//父list需要显示的数据
newint[]{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,
newString[]{NAME,IS_EVEN},
newint[]{android.R.id.text1,android.R.id.text2}
);
setListAdapter(mAdapter);
}

}