3.0 以后系统直接支持了ListView. 关于ListView 的国内资料匮乏,大多数例子都是转来转去。由于初学android, 鄙人在搜索资料的时候遇到了不少麻烦~很是郁闷和苦恼~深感国内学习氛围确实怪异，学习方式需要改变。应该多去查看官方文档。。。。
话不多说，现在开始listView 实现：
这是文档列出的支持的布局和widget控件：
A RemoteViews object (and, consequently, an App Widget) can support the following layout classes:
And the following widget classes:
- AnalogClock
- Button
- Chronometer
- ImageButton
- ImageView
- ProgressBar
- TextView
- ViewFlipper
- ListView
- GridView
- StackView
- AdapterViewFlipper
Descendants of these classes are not supported
其中有ListView和 GridView 等控件。
android 中实现 appWidget 有自己的一套机制：
1. widget 的支持，AppWidgetProvider 类的实现。
覆盖在 AppWidgetProvider 的 OnReceive() 函数，从android的源码中可以知道，AppWidgetProvider 的 OnUpdate() ， OnEnable(), OnDelete() 等方法都是从 OnReceive() 方法中分配进去的。即所有的广播先通过OnReceive()函数，再分配到OnUpdate()等函数去。
public void onReceive(Context context, Intent intent) {
// Protect against rogue update broadcasts (not really a security issue,
// just filter bad broacasts out so subclasses are less likely to crash).
String action = intent.getAction();
if (AppWidgetManager.ACTION_APPWIDGET_UPDATE.equals(action)) {
Bundle extras = intent.getExtras();
if (extras != null) {
int[] appWidgetIds = extras.getIntArray(AppWidgetManager.EXTRA_APPWIDGET_IDS);
if (appWidgetIds != null && appWidgetIds.length > 0) {
this.onUpdate(context, AppWidgetManager.getInstance(context), appWidgetIds);
}
}
}
else if (AppWidgetManager.ACTION_APPWIDGET_DELETED.equals(action)) {
Bundle extras = intent.getExtras();
if (extras != null && extras.containsKey(AppWidgetManager.EXTRA_APPWIDGET_ID)) {
final int appWidgetId = extras.getInt(AppWidgetManager.EXTRA_APPWIDGET_ID);
this.onDeleted(context, new int[] { appWidgetId });
}
}
else if (AppWidgetManager.ACTION_APPWIDGET_ENABLED.equals(action)) {
this.onEnabled(context);
}
else if (AppWidgetManager.ACTION_APPWIDGET_DISABLED.equals(action)) {
this.onDisabled(context);
}
}
// END_INCLUDE(onReceive)
注意到：
String action = intent.getAction();
这里 intent 先获取 action, 通过action 来获取到广播并区分类型，所以自己定义 action 通过 PendingIntent 来实现各种跳转~
到这里先摆下基础的文件吧：
这里需要注意到的是：android中的xml 文件不能有大写字母。区分单词用最好用 _ 符号。否则找不到文件名。
provider_info 文件，提供 appWidget 的一些基本控制信息。
<?xml version="1.0" encoding="utf-8"?> <appwidget-provider xmlns:android="http://schemas.android.com/apk/res/android" android:minWidth = "294dp" android:minHeight = "367dp" android:updatePeriodMillis = "1000" android:initialLayout = "@layout/listview" android:background="#0000ff" > </appwidget-provider>
listview 文件： ListView 控件就在内部：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="294dp"
android:layout_height="400dp">
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="360dp"
android:minHeight="100dp"
android:id="@+id/listviewWrapper"
>
<ListView
android:layout_height = "360dp"
android:layout_width = "294dp"
android:background="#000000"
android:id = "@+id/myListView"
/>
</LinearLayout>
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="@id/listviewWrapper"
android:layout_alignParentLeft="true"
android:id="@+id/refresh"
android:text="refresh"
>
</Button>
</RelativeLayout>
下面是list_item 文件：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:textColor="#ff0000"
android:layout_marginTop="5px"
android:layout_marginBottom="5px"
android:paddingBottom="25px"
android:paddingTop="5px"
android:textSize="60px"
android:id="@+id/item"
/>
<ImageView
android:id="@+id/imageItem"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignRight="@id/item"
/>
</RelativeLayout>
list 的 item 中也可以添加 ImageView 等appWidget 支持的控件。
这是manifest 问件：
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.zgc.AppWidget6"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="15" />
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name" >
<receiver android:name=".MyWidgetProvider">
<meta-data android:name="android.appwidget.provider"
android:resource="@xml/provider_info" >
</meta-data>
<intent-filter >
<action android:name="android.appwidget.action.APPWIDGET_UPDATE"></action>
</intent-filter>
</receiver>
<service android:name=".MyWidgetService"
android:permission="android.permission.BIND_REMOTEVIEWS"
android:exported="false" ></service>
</application>
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
</manifest>
其中 service 提供 name 是 MyWidgetService ，他是继承RemoteViewsService 类。是我们需要为 远程 ListView 提供 数据源的服务。
RemoteViewsService的是个服务。其中：
public RemoteViewsFactory onGetViewFactory(Intent intent) {
return new ListRemoteViewsFactory(this.getApplicationContext(), intent);
}
ListRemoteViewsFactory 这里就充当 ListView 的数据源。
就好比在activity 中使用ListView 一样。也需要通过AdapterView 来为ListView 提供数据源。不过AdatperView中提供了每一Item的方法。
具体逻辑如图：
下面是 service 的源代码：
public class MyWidgetService extends RemoteViewsService {
@Override
public RemoteViewsFactory onGetViewFactory(Intent intent) {
return new ListRemoteViewsFactory(this.getApplicationContext(), intent);
}
@Override
public void onCreate() {
// TODO Auto-generated method stub
System.out.println("service in onCreate");
super.onCreate();
}
@Override
public void onDestroy() {
// TODO Auto-generated method stub
System.out.println("service in onDestory");
super.onDestroy();
}
@Override
public boolean onUnbind(Intent intent) {
// TODO Auto-generated method stub
System.out.println("service in onUnbind");
return super.onUnbind(intent);
}
@Override
public void onRebind(Intent intent) {
// TODO Auto-generated method stub
System.out.println("service in onRebind");
super.onRebind(intent);
}
@Override
public void onStart(Intent intent, int startId) {
// TODO Auto-generated method stub
System.out.println("service in onStart");
super.onStart(intent, startId);
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
// TODO Auto-generated method stub
return super.onStartCommand(intent, flags, startId);
}
}
class ListRemoteViewsFactory implements RemoteViewsService.RemoteViewsFactory {
private static int mCount = 0;
private List<WidgetItem> mWidgetItems = new ArrayList<WidgetItem>();
private List<String> mWidgetItemsAttr= new ArrayList<String>();
private Context mContext;
private int mAppWidgetId;
private String url = "http://10.40.73.77/php/getData.php";
public static int whichPage = 0;
public static int mainPageId = -1;
public static int secPageId = -1;
public static final int mainPage = 0;
public static final int secPage = 1;
public static List<Integer> checkPos = new ArrayList<Integer>();
//public static int[] checkPosArr = new int[100];
public ListRemoteViewsFactory(Context context, Intent intent){
mContext = context;
mAppWidgetId = intent.getIntExtra(AppWidgetManager.EXTRA_APPWIDGET_ID,
AppWidgetManager.INVALID_APPWIDGET_ID);
}
@Override
public void onCreate() {
System.out.println("onCreate in factory");
// TODO Auto-generated method stub
try {
Thread.sleep(3000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
@Override
public int getCount() {
// TODO Auto-generated method stub
if(whichPage == mainPage){
mCount = mWidgetItems.size();
}
else if(whichPage == secPage){
mCount = mWidgetItemsAttr.size();
}
return mCount;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public RemoteViews getLoadingView() {
// TODO Auto-generated method stub
System.out.println("getLoadingView");
return null;
}
@Override
public RemoteViews getViewAt(int position) {
System.out.println("getViewAt");
// TODO Auto-generated method stub
RemoteViews rv = new RemoteViews(mContext.getPackageName(), R.layout.list_item);
switch(whichPage){
case mainPage :
if(-1 == mainPageId){ //refresh main page
System.out.println("getViewAt mainPage refresh");
rv.setTextViewText(R.id.item, mWidgetItems.get(position).text);
Bundle extras = new Bundle();
extras.putInt("page", 0);
extras.putInt(MyWidgetProvider.EXTRA_ITEM, position);
extras.putString("name", mWidgetItems.get(position).text);
Intent fillInIntent = new Intent();
fillInIntent.putExtras(extras);
rv.setOnClickFillInIntent(R.id.item, fillInIntent);
}
else{ //refresh to secPage list content
System.out.println("getViewAt mainPage item click");
mainPageId = -1;
}
break;
case secPage:
if(-1 == secPageId){ //refresh when click back button, but I only have one home button
//refresh second list page
System.out.println("getViewAt secPage refresh");
rv.setTextViewText(R.id.item, mWidgetItemsAttr.get(position));
rv.setImageViewResource(R.id.imageItem, R.drawable.checkbox);
Bundle extras = new Bundle();
extras.putInt("page", 1);
extras.putInt(MyWidgetProvider.EXTRA_ITEM, position);
Intent fillInIntent = new Intent();
fillInIntent.putExtras(extras);
rv.setOnClickFillInIntent(R.id.item, fillInIntent);
rv.setOnClickFillInIntent(R.id.imageItem, fillInIntent);
}
else{ //change positon
rv.setTextViewText(R.id.item, mWidgetItemsAttr.get(position));
if(-1 != checkPos.indexOf(position)){
//change list item picture to be checked
rv.setImageViewResource(R.id.imageItem, R.drawable.checkedbox);
}
else{
rv.setImageViewResource(R.id.imageItem, R.drawable.checkbox);
}
//每一个 item 都需要从新赋值。否则会出错！！具体原因没有查明
Bundle extras = new Bundle();
extras.putInt("page", 1);
extras.putInt(MyWidgetProvider.EXTRA_ITEM, position);
Intent fillInIntent = new Intent();
fillInIntent.putExtras(extras);
rv.setOnClickFillInIntent(R.id.item, fillInIntent);
rv.setOnClickFillInIntent(R.id.imageItem, fillInIntent);
}
break;
default: ;
}
return rv;
}
@Override
public int getViewTypeCount() {
// TODO Auto-generated method stub
return 1;
}
@Override
public boolean hasStableIds() {
// TODO Auto-generated method stub
return true;
}
@Override
public void onDataSetChanged() {
// TODO Auto-generated method stub
System.out.println("onDataSetChanged");
//this func is get data
mWidgetItems.clear();
switch(whichPage){
case mainPage :
System.out.println("onDataSetChanged_mainPage");
if(-1 == mainPageId){ //refresh main page
try{
URL reqURL = new URL(url);
BufferedReader br = new BufferedReader(new InputStreamReader(reqURL.openStream(), "gbk"));
StringBuffer sb = new StringBuffer();
String line;
while(null != (line = br.readLine())){
sb.append(line);
}
br.close();
ArrayList <Map<String, Object>> mList= new ArrayList<Map<String, Object>>();
JSONArray arr_json = new JSONArray(sb.toString());
for(int i = 0, len = arr_json.length(); i < len; i++){
String strName = arr_json.getJSONObject(i).getString("name");
String strUrl = arr_json.getJSONObject(i).getString("url");
int id = arr_json.getJSONObject(i).getInt("id");
Map<String, Object> map = new HashMap<String, Object>();
mWidgetItems.add(new WidgetItem(strName, id));
map.put("name", strName);
map.put("url", strUrl);
mList.add(map);
}
mCount = mWidgetItems.size();
}catch(Exception e){
Toast.makeText(mContext, "can't connect server", Toast.LENGTH_LONG).show();
}
}
else{ //
System.out.println("onDataSetChanged_mainPage else");
WidgetItem item = mWidgetItems.get(mainPageId);
}
System.out.println("onDataSetChanged_-1");
break;
case secPage: //here can get more info from server, but no need to get more infomation,
if(-1 == secPageId){
mWidgetItemsAttr.clear();
System.out.println("onDataSetChanged_secPage -1");
mWidgetItemsAttr.add("zhang");
mWidgetItemsAttr.add("gui");
mWidgetItemsAttr.add("chuang");
mWidgetItemsAttr.add("hui");
mWidgetItemsAttr.add("cong");
mWidgetItemsAttr.add("gui");
mWidgetItemsAttr.add("chuang");
mWidgetItemsAttr.add("hui");
mWidgetItemsAttr.add("cong");
mWidgetItemsAttr.add("gui");
mWidgetItemsAttr.add("chuang");
mWidgetItemsAttr.add("hui");
mWidgetItemsAttr.add("cong");
mWidgetItemsAttr.add("cong");
}
else{
System.out.println("onDataSetChanged_secPage else");
}
break;
default: return ;
}
}
@Override
public void onDestroy() {
System.out.println("onDestory in factory");
// TODO Auto-generated method stub
mWidgetItems.clear();
}
}
注意到几个方法：
public void onDataSetChanged(){.....}
public RemoteViews getViewAt(int position) {....}
public int getCount() {....}
onDateSetChanged(){...} 方法在你使用的 MyWidgetProvider 的 onReceive() 和 onUpdate() 方法中调用
AppWidgetManager 的实例的方法: mgr.notifyAppWidgetViewDataChanged(appIds, R.id.myListView); 来更新要求更新数据源：
首先就会调用 ：
onDataSetChanged(){.....}
然后在调用 getViewAt(int position){....}
其中getViewAt 的参数 position 就是你的ListView中每一项 item 的位置。从 0 计数。
其中你必须 override 的 getCount()方法是返回你的ListView item 的总数。这个自己必须返回自己的数据才能让getViewAt的postion能够计数。
你获取数据的方式比如http从服务器获取数据的话，就需要放在onDateSetChagged()方法里。
当然 public RemoteViews getLoadingView(){...} 也可以。不过要注意放回的是RemoteViews 就说明这是要更新界面的，这个函数的作用就是在你更新界面的时候如果耗时就会显示 正在加载... 的默认字样，但是你可以更改这个界面。需要返回一个 RemoteViews 类型。其中你可以使用RemoteViews 去切换自己定义的 Layout 。
关于 remoteViews 的实例的方法：
rv.setOnClickFillInIntent(R.id.item, fillInIntent);
在下面会解释。
下面是provider:
public class MyWidgetProvider extends AppWidgetProvider{
public static final String TOAST_ACTION = "com.zgc.listwidget.TOAST_ACTION";
public static final String EXTRA_ITEM = "com.zgc.listwidget.EXTRA_ITEM";
public static final String TO_SITE = "com.zgc.listwidget.TO_SITE";
public static final String SITE = "com.zgc.listwidget.SITE";
public static final String BACK_HOME = "com.zgc.listwidget.BACK_HOME";
public static String PicName = "";
public static final String REFRESH = "com.zgc.listwidget.REFRESH";
public static final String ITEM = "com.zgc.AppWidget6.ITEM";
@Override
public IBinder peekService(Context myContext, Intent service) {
// TODO Auto-generated method stub
System.out.println("peekService in provider");
return super.peekService(myContext, service);
}
@Override
public void onDeleted(Context context, int[] appWidgetIds) {
// TODO Auto-generated method stub
System.out.println("onDeleted in Provider");
super.onDeleted(context, appWidgetIds);
}
@Override
public void onDisabled(Context context) {
// TODO Auto-generated method stub
System.out.println("onDisabled in Provider");
super.onDisabled(context);
}
@Override
public void onEnabled(Context context) {
// TODO Auto-generated method stub
System.out.println("onEnabled in Provider");
super.onEnabled(context);
}
@Override
public void onReceive(Context context, Intent intent) {
// TODO Auto-generated method stub
AppWidgetManager mgr = AppWidgetManager.getInstance(context);
ComponentName cmpName = new ComponentName(context, MyWidgetProvider.class);
if (intent.getAction().equals(ITEM)) {
System.out.println("item action");
int pageNum = intent.getIntExtra("page", 1);
int itemPos = intent.getIntExtra(EXTRA_ITEM, 0);
if(0 == pageNum){
System.out.println("item action 0 page");
ListRemoteViewsFactory.secPageId = -1;
ListRemoteViewsFactory.whichPage = ListRemoteViewsFactory.secPage;
int[] appIds = mgr.getAppWidgetIds(cmpName);
mgr.notifyAppWidgetViewDataChanged(appIds, R.id.myListView);
//change refresh to commit button ,here no need to reload listview
RemoteViews rv2 = new RemoteViews(context.getPackageName(), R.layout.listview);
rv2.setTextViewText(R.id.refresh, "commit");
Intent commitIntent = new Intent(context, MyWidgetProvider.class);
commitIntent.setData(Uri.parse(commitIntent.toUri(Intent.URI_INTENT_SCHEME)));
commitIntent.setAction(SITE);
PendingIntent commitPendingIntent = PendingIntent.getBroadcast(context, 0,
commitIntent, PendingIntent.FLAG_UPDATE_CURRENT);
rv2.setOnClickPendingIntent(R.id.refresh, commitPendingIntent);
mgr.updateAppWidget(appIds, rv2);
}
else if(1 == pageNum){
System.out.println("item action 1 page");
ListRemoteViewsFactory.secPageId = itemPos;
if(-1 == ListRemoteViewsFactory.checkPos.indexOf(itemPos)){
ListRemoteViewsFactory.checkPos.add(itemPos);
}
else{
ListRemoteViewsFactory.checkPos.remove(ListRemoteViewsFactory.checkPos.indexOf(itemPos));
}
int[] appIds = mgr.getAppWidgetIds(cmpName);
mgr.notifyAppWidgetViewDataChanged(appIds, R.id.myListView);
}
}
else if(intent.getAction().equals(SITE)){
System.out.println("in receive commit SITE action");
RemoteViews rv = new RemoteViews(context.getPackageName(), R.layout.img);
int id = R.drawable.uliuli;
if(PicName.equals("google")){
id = R.drawable.uliuli;
}
else if(PicName.equals("douban")){
id = R.drawable.uliuli;
}
rv.setImageViewResource(R.id.displayImage, id);
Intent homeIntent = new Intent(context, MyWidgetProvider.class);
homeIntent.setAction(BACK_HOME);
//homeIntent.setAction(AppWidgetManager.ACTION_APPWIDGET_UPDATE);
homeIntent.setData(Uri.parse(homeIntent.toUri(Intent.URI_INTENT_SCHEME)));
PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, homeIntent,
PendingIntent.FLAG_UPDATE_CURRENT);
rv.setOnClickPendingIntent(R.id.backHome, pendingIntent);
mgr.updateAppWidget(cmpName, rv);
//Toast.makeText(context, "Touched view zhang", Toast.LENGTH_SHORT).show();
}
else if(intent.getAction().equals(BACK_HOME)){
System.out.println("back_home ");
int[] appWidgetIds = mgr.getAppWidgetIds(cmpName);
//mgr.notifyAppWidgetViewDataChanged(appWidgetIds, R.id.myListView);
Intent serviceIntent = new Intent(context, MyWidgetService.class); //
//intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetIds[i]);
serviceIntent.setData(Uri.parse(serviceIntent.toUri(Intent.URI_INTENT_SCHEME)));
RemoteViews rv = new RemoteViews(context.getPackageName(), R.layout.listview);
rv.setRemoteAdapter(R.id.myListView, serviceIntent);
Intent toastIntent = new Intent(context, MyWidgetProvider.class);
toastIntent.setAction(MyWidgetProvider.ITEM);
intent.setData(Uri.parse(intent.toUri(Intent.URI_INTENT_SCHEME)));
PendingIntent toastPendingIntent = PendingIntent.getBroadcast(context, 0, toastIntent,
PendingIntent.FLAG_UPDATE_CURRENT);
rv.setPendingIntentTemplate(R.id.myListView, toastPendingIntent);
mgr.updateAppWidget(appWidgetIds, rv);
Intent refreshIntent = new Intent(context, MyWidgetProvider.class);
refreshIntent.setAction(REFRESH);
PendingIntent refreshPendingIntent = PendingIntent.getBroadcast(context, 0,
refreshIntent, 0);
rv.setOnClickPendingIntent(R.id.refresh, refreshPendingIntent);
ListRemoteViewsFactory.whichPage = ListRemoteViewsFactory.mainPage;
ListRemoteViewsFactory.mainPageId = -1;
mgr.updateAppWidget(cmpName, rv);
mgr.notifyAppWidgetViewDataChanged(appWidgetIds, R.id.myListView);
System.out.println("zhanggui");
//Toast.makeText(context, "Touched view back home", Toast.LENGTH_SHORT).show();
}
else if(intent.getAction().equals(REFRESH)){
System.out.println("refresh button begin");
int[] appWidgetIds = mgr.getAppWidgetIds(cmpName);
mgr.notifyAppWidgetViewDataChanged(appWidgetIds, R.id.myListView);
System.out.println("refresh button end");
}
super.onReceive(context, intent);
}
@Override
public void onUpdate(Context context, AppWidgetManager appWidgetManager,
int[] appWidgetIds) {
System.out.println("onUpdate");
// TODO Auto-generated method stub
for(int i = 0; i < appWidgetIds.length; i++){
Intent intent = new Intent(context, MyWidgetService.class);
intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetIds[i]);
// When intents are compared, the extras are ignored, so we need to embed the extras
// into the data so that the extras will not be ignored.
intent.setData(Uri.parse(intent.toUri(Intent.URI_INTENT_SCHEME)));
RemoteViews rv = new RemoteViews(context.getPackageName(), R.layout.listview);
rv.setRemoteAdapter(R.id.myListView, intent);
//rv.setEmptyView(R.id.myListView, R.id.empty);
Intent refreshIntent = new Intent(context, MyWidgetProvider.class);
refreshIntent.setAction(REFRESH);
PendingIntent refreshPendingIntent = PendingIntent.getBroadcast(context, 0,
refreshIntent, 0);
rv.setOnClickPendingIntent(R.id.refresh, refreshPendingIntent);
Intent toastIntent = new Intent(context, MyWidgetProvider.class);
toastIntent.setAction(MyWidgetProvider.ITEM);
//toastIntent.putExtra("page", 0); // main page
intent.setData(Uri.parse(intent.toUri(Intent.URI_INTENT_SCHEME)));
PendingIntent toastPendingIntent = PendingIntent.getBroadcast(context, 0, toastIntent,
PendingIntent.FLAG_UPDATE_CURRENT);
rv.setPendingIntentTemplate(R.id.myListView, toastPendingIntent);
appWidgetManager.updateAppWidget(appWidgetIds[i], rv);
}
super.onUpdate(context, appWidgetManager, appWidgetIds);
}
}
首先看onUpdate() 函数，默认是从这里先进去的：
申明intent 后使用：
intent.setData(Uri.parse(intent.toUri(Intent.URI_INTENT_SCHEME)));
用：这是为了让 intent 能够带上 extras 数据一起传递，否则在intent的比较的过程中会被忽略掉。这里的比较应该是在同一个代码块中有多个intent的时候会发生比较吧（猜测：因为当一条逻辑执行路径上代码块中只有一个Intent发送的时候能够带数据(不适用intent.setData函数)，但是有多个Intent的话不行）
PendingIntent 的使用不再解释。不过这里的 remoteView 实例使用：
rv.setPendingIntentTemplate(R.id.myListView, toastPendingIntent);
listView 使用 setPendingIntentTemplate 方法，当你点击 ListView 中的任何一个item 时都会发送 toastPendingIntent ，在我们的 service 中的getViewAt() 方法中，为每一个item 都设置了一个 intent ：
rv.setOnClickFillInIntent(R.id.item, fillInIntent);
其中 remoteViews 的setOnClickFillInIntent() 是将 fillIntent 合并到 toastPendingIntent 中去。就是两个 intent 合并了。
具体的合并方法是Intent中的fillIn(..) 方法：
Intent A ： {data="foo", categories="bar"}
Intent B ： {action="gotit", data-type="some/thing", categories="one","two"}.
调用 fillIn()： A.fillIn(B, Intent.FILL_IN_DATA)
结果： A : {action="gotit", data-type="some/thing", categories="bar"}.
注意到 action 还是你在 onUpdate()中设置的 action,当然你也可以在 item 中的 fillInIntent 设置action.但是不好。
这里可以在每个 item 的 fillInIntent 中 使用 putExtras() 方法让Intent 带每个item 的 位置号码 来区分每个 item.
机制基本上已经说完，还有一点就是：
RemoteViewsService 中每次获取数据都会重新创建 service 和 销毁 service ，但是 RemoteViewsService.RemoteViewsFactory
的销毁则是在 机器上把 appWidget 删除后发生。就好像 RemoteViewsService.RemoteViewsFactory 是个数据库。你每次去访问这个数据源都会创建 一个 RemoteViewsService 然后销毁。这个源于我android学习1月，也不清楚内部机制。没仔细研究。等研究了再发文表上。
还有 AppWidgetProvider 类的实例是每发送一次 intent （即每一次 boardcast） 就新建一次，所以如果需要做 flag 来表示按钮是否check的话，最好就先声明为 static 类型或者放到其他类中。
其余的就是自己逻辑的实现：
我这里实现了 两个 ListView 的数据加载(通过http从服务器获取数据)和点入每条item进入另外的页面(这里也是在listView上从新加载数据，但是可以区分每个Item。也可以自己加载其他的layout)。还可以实现回到第一个加载的页面。其实可以做到回到上一个页面。
博客园不能奉上源代码，可惜。。。有需要的留言~
