Jak zaobserwować zmianę contentprovider? android

Question

I'v stworzył Contentprovide i realizuje to update (metoda) tak:

@Override 
    public int update(Uri uri, ContentValues values, String selection, 
     String[] selectionArgs) { 
     final SQLiteDatabase db = mHelper.getWritableDatabase(); 
     int count = db.update(InslideDB.FOLDER_TABLE, values, selection, selectionArgs); 

     /* To notify the observer */ 
     this.getContext().getContentResolver().notifyChange(URI, null); 
     return count; 
} 

Jak mogę otrzymywać powiadomienia w moim appwidget? Dzięki!

Próbuję to Resolver ale nie Log (zmienione) -------------------- Data druku:

class DataProviderObserver extends ContentObserver { 
    private AppWidgetManager mAppWidgetManager; 
    private ComponentName mComponentName; 

    DataProviderObserver(AppWidgetManager mgr, ComponentName cn, Handler h) { 
     super(h); 
     mAppWidgetManager = mgr; 
     mComponentName = cn; 
    } 

    @Override 
    public void onChange(boolean selfChange) { 
     super.onChange(selfChange); //NOTE: Have to call this. dwy. 

     // The data has changed, so notify the widget that the collection view needs to be updated. 
     // In response, the factory's onDataSetChanged() will be called which will requery the 
     // cursor for the new data. 

     Log.d("PresenterWidgetProvider", "--------------------Date Changed"); 

     mAppWidgetManager.notifyAppWidgetViewDataChanged(
       mAppWidgetManager.getAppWidgetIds(mComponentName), R.id.inslide_grid); 
    } 
} 


public class PresenterWidgetProvider extends AppWidgetProvider{ 

    private static final String AUTHORITY = "com.apps.slide"; 

    static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/folder"); 

    public static final String EXTRA_INSLIDE_PATH = "EXTRA_WIDGET_PATH"; 
    private static HandlerThread sWorkerThread; 
    private static Handler sWorkerQueue; 
    private static DataProviderObserver sDataObserver; 

    public PresenterWidgetProvider() { 

     // Start the worker thread to update Content Provider. 
     sWorkerThread = new HandlerThread("PresenterWidgetProvider worker"); 
     sWorkerThread.start(); 
     sWorkerQueue = new Handler(sWorkerThread.getLooper()); 

    } 

    @Override 
    public void onEnabled(Context context) { 
     // Register for external updates to the data to trigger an update of the widget. When using 
     // content providers, the data is often updated via a background service, or in response to 
     // user interaction in the main app. To ensure that the widget always reflects the current 
     // state of the data, we must listen for changes and update ourselves accordingly. 
     final ContentResolver r = context.getContentResolver(); 
     if (sDataObserver == null) { 
      final AppWidgetManager mgr = AppWidgetManager.getInstance(context); 
      final ComponentName cn = new ComponentName(context, PresenterWidgetProvider.class); 
      sDataObserver = new DataProviderObserver(mgr, cn, sWorkerQueue); 
      r.registerContentObserver(CONTENT_URI, true, sDataObserver); 
      Log.d("PresenterWidgetProvider", "--------------------onEnabled. sDataObserver = " + sDataObserver); 
     } 
    } 

Więc ostatecznie rozwiązać go przez 4 etapy:

1. Dodaj this.getContext().getContentResolver().notifyChange(URI, null);

do updat ContentProvider za() wkładki() delete() wywołania zwrotne.

1. Utwórz nowy obserwator i nowy wątek, aby go obsłużyć.

2. Zadzwoń notifyAppWidgetViewDataChanged() w onChange obserwatora().

3. Usuń widget i umieść nowy.

To wszystko.

Answer 1

Można użyć klasy ContentObserver. Trzeba tylko zaimplementować tę klasę i użyć metody getContentResolver().registerContentObserver(), aby zarejestrować obserwatora.