android widget的自动更新

public   class  WidgetService  extends  Service
{

    @Override
    public  IBinder onBind(Intent intent)
    {
        return   null ;
    }

    @Override
    public   void  onStart(Intent intent,  int  startId)
    {
        super .onStart(intent, startId);
        RemoteViews rv = new  RemoteViews( this .getPackageName(), R.layout.app);
        rv.setTextViewText(R.id.av1, new  Date().toLocaleString());
        ComponentName cn = new  ComponentName( this , DeskMain. class );
        AppWidgetManager am = AppWidgetManager.getInstance(this );
        am.updateAppWidget(cn, rv);
    }
}
public   class  DeskMain  extends  AppWidgetProvider
{

    @Override
    public   void  onUpdate(Context context, AppWidgetManager appWidgetManager,
            int [] appWidgetIds)
    {
        Log.i("syso" ,  "update3..................." );
        Intent intent=new  Intent(context ,WidgetService. class );
        PendingIntent refreshIntent=PendingIntent.getService(context, 0 , intent,  0 );
        AlarmManager alarm=(AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
        alarm.setRepeating(AlarmManager.RTC, 0 ,  1000 , refreshIntent);
        context.startService(intent);
    }

    @Override
    public   void  onReceive(Context context, Intent intent)
    {
        Log.i("syso" ,  "receive..................." );
        super .onReceive(context, intent);
    }

AndroidManifest.xml

<? xml   version = "1.0"   encoding = "utf-8" ?>
< manifest   xmlns:android = "http://schemas.android.com/apk/res/android"
      package = "com.app"
      android:versionCode = "1"
      android:versionName = "1.0" >
< uses-permission   android:name = "android.permission.ACCESS_FINE_LOCATION" > </ uses-permission >


    < application   android:icon = "@drawable/icon"   android:label = "@string/app_name"   android:screenOrientation = "portrait"   android:permission = "android.permission.ACCESS_FINE_LOCATION" >
        < activity   android:name = ".Main"
                  android:label = "@string/app_name" >
     <!--  -->
    < receiver
      android:label = "@string/app_name"
      android:name = ".DeskMain" >
            < intent-filter >
                < action   android:name = "android.appwidget.action.APPWIDGET_UPDATE"   />
            </ intent-filter >
     < meta-data   android:name = "android.appwidget.provider"
        android:resource = "@xml/my_widget_provider"   >
      </ meta-data >
    </ receiver >
    < service   android:name = "WidgetService"   />

    </ application >
    < uses-sdk   android:minSdkVersion = "7"   />

</ manifest >

我们在做widget开发时，要解决的主要问题是怎么做到实时刷新，比如当我们在一个activity里点击插入或删除操作时，能够使widget上显示的数据条数刷新
下面是在activity里要实现的代码:

Intent intent =  new  Intent( "com.android.CLICK" );
            ResultActivity.this .sendBroadcast(intent);

我们还要在AndroidMainifest.xml的<intent-filter>里定制:

<action android:name= "com.android.CLICK" ></action>

在widget类里我们用onReceive方法:

//把数据显示上widget
            RemoteViews views = new  RemoteViews(context.getPackageName(), R.layout.main);
            String strLine = System.getProperty("line.separator" );
            views.setTextViewText(R.id.note_text, “要显示的信息”);

            //添加响应事件
            intent = new  Intent(context, OperateActivity. class );


            PendingIntent Pintent= PendingIntent.getActivity(context, 0 , intent,  0 );
            views.setOnClickPendingIntent(R.id.widget, Pintent);

            //最后更新
            AppWidgetManager  appWidgetManager=AppWidgetManager.getInstance(context);
            appWidgetManager.updateAppWidget(new  ComponentName(context, Note. class ), views);