我创建了一个 Contentprovide 并实现了它的 update() 方法，如下所示：
@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;
}
如何在我的 appwidget 中获得通知？谢谢！
我正在尝试这个解析器，但没有日志（--------日期更改）打印：
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);
}
}
所以，我终于通过4个步骤解决了它：
- 添加
this.getContext().getContentResolver().notifyChange(URI, null);
到 ContentProvider 的 updat() insert() delete() 回调。
创建一个新的观察者和新的线程来处理它。
在 Observer 的 onChange() 中调用 notifyAppWidgetViewDataChanged()。
删除小部件并放置一个新的。
就是这样。