AppWidgetManager.getAppWidgetIds in activity returns an empty list

问题:

I have an appwidget that I'm trying to update from an activity.

To do that, I need the appwidget id.

I've used AppWidgetManager.getAppWidgetIds but it always returns an empty list.

I also used AppWidgetManager.getInstalledProviders to make sure that my ComponentName is correct, but still I get an empty list.

I've seen all the other questions about this, but I couldn't find something that worked for me.

Is there another way to solve this? or another way to update the widget?

My code:

ComponentName name = new ComponentName(packageName, boardcastReceiverClass); AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(this); int[] ids = appWidgetManager.getAppWidgetIds(name); if (ids != null && ids.length > 0) {    getApplicationContext().sendBroadcast(getUpdateIntent(ids[0])); } 

Thanks.

UPDATE: I should mention that my AppWidgetProvider is in a library project. According to the ComponentName I get with getInstalledProviders, I used the package name of my app and the class name with the package name of the library.

回答1:

You can access your widget without knowing id

appWidgetManager.updateAppWidget(new ComponentName(this.getPackageName(),Widget.class.getName()), views); 

This let you access the widget without having to know the 'appWidgetID'. Then in activity:

Intent intent = new Intent(this, Settings.class); PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent, 0);  views.setOnClickPendingIntent(R.id.btnActivate, pendingIntent);  AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(this); appWidgetManager.updateAppWidget(new ComponentName(this.getPackageName(), Widget.class.getName()), views); finish(); 

回答2:

I'm working on something similar and here is the simplest way I got it to work.

In your service class put this wherever you want to trigger a widget update:

Intent brIntent = new Intent(AppWidgetManager.ACTION_APPWIDGET_UPDATE); sendBroadcast(brIntent); 

This will cause the onReceive(Context context, Intent intent) method in your AppWidgetProvider class to be called. Then onRecieve can call code to update the widget. For a sample, here's what I used. I'm merely updating the text of the widget:

        //Sample output text     String text = "My cat's name is wiggles.";     //get an AppWidgetManager     AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(context);     //getComponentName     ComponentName thisWidget = new ComponentName(context, MyWidgetProvider.class);     //get the IDs for all the instances of this widget     int[] allWidgetIds = appWidgetManager.getAppWidgetIds(thisWidget);     //update all of the widgets     for (int widgetId : allWidgetIds) {         //get any views in this instance of the widget         RemoteViews remoteViews = new RemoteViews(context.getPackageName(), R.layout.widget_layout);         // Set the text         remoteViews.setTextViewText(R.id.widgetField,  text);         //update the widget with any change we just made         appWidgetManager.updateAppWidget(widgetId, remoteViews);     } 

回答3:

To get the app widget ID.. use this below code

onReceive() method use this below code

int appWidgetId = intent.getExtras().getInt(AppWidgetManager.EXTRA_APPWIDGET_ID, AppWidgetManager.INVALID_APPWIDGET_ID); 

in onUpdate() you get the list of ids already as the parameter!

If you want to update it from activity use this

 Intent intent = new Intent(this, [activityname].class);     intent.setAction("android.appwidget.action.APPWIDGET_UPDATE");     int ids[] = AppWidgetManager.getInstance(getApplication()).getAppWidgetIds(new ComponentName(getApplication(), [activityname].class));     intent.putExtra(AppWidgetManager.EXTRA_APPWIDGET_IDS,ids);     sendBroadcast(intent); 

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