Android应用程序小部件更新问题

Question

Here is what I am dealing with.

I have a widget associated to my Android App which I want to update every 10 minutes (currently using AlarmManager) only if the screen is ON. If the screen is OFF the alarms for the pendingIntent are cancelled. Once the screen comes ON again I check if the last update and current time has a difference of 10 minutes or more, if it is I send out a broadcast to update the widget.

What happens and is the problem is the alarms for the pending Intent probably are not cancelled (probably) and the widget update is executed for all the alarms for the pendingIntent that were stacked up when the screen was OFF.

Here are some code snippets.

@Override
public void onReceive(Context context, Intent intent) {
        check_intent = intent.getAction();

            if(check_intent.equals("android.appwidget.action.APPWIDGET_UPDATE")){

                 mAppPreferences = PreferenceManager.getDefaultSharedPreferences(context);
                 int saved_num_widgets = mAppPreferences.getInt(NUM_WIDGETS, 0);
        /*Check if there is atleast one widget on homescreen*/       
                 if (saved_num_widgets>0){
                        boolean check = CheckScreenOn.check_screen_on(context);
/*Check if Screen is ON*/
                            if(check == true){
                                                Intent widgetUpdate = new Intent(context, MyWidget.class);
                                                widgetUpdate.setAction(AppWidgetManager.ACTION_APPWIDGET_UPDATE);
                                                alarms = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
                                                newPending = PendingIntent.getBroadcast(context, 0, widgetUpdate,0);
                                                alarms.set(AlarmManager.ELAPSED_REALTIME, SystemClock.elapsedRealtime()+ PERIOD, newPending);
                                                context.startService(new Intent(context, UpdateService.class));
                            }
                            else{
                                alarms.cancel(newPending);
/*Screen is OFF no point updating the widget, cancel Alarms and do nothing*/
                            }
                     }
                     else{
                            int duration = Toast.LENGTH_LONG;
                            CharSequence text = "Please place My Widget on your home screen to keep earning money.";
                            Toast toast = Toast.makeText(context, text, duration);
                            toast.show();
                     }
                    }   
                if(check_intent.equals("android.appwidget.action.APPWIDGET_ENABLED")){
                    this.onEnabled(context);
                }
                if(check_intent.equals("android.appwidget.action.APPWIDGET_DELETED")){
                    this.onDeleted(context);
                }
                if(check_intent.equals("android.appwidget.action.APPWIDGET_DISABLED")){
                    this.onDisabled(context);
                }


    }

Here is the BroadcastReceiver that receives the SCREEN_ON broadcast and sends out the request for the widget update if current time - last time widget was updated >= 10 minutes.

registerReceiver(new BroadcastReceiver() {

              @Override
              public void onReceive(Context context, Intent intent) {
                // ... 
                long update_interval = mAppPreferences.getLong(LASTUPDATETIME, 0);
                long curtimemillis = System.currentTimeMillis();
                long calculate_interval = curtimemillis - update_interval;
                if(calculate_interval >= PERIOD){
                    int saved_num_widgets = mAppPreferences.getInt(NUM_WIDGETS, 0);

                    if (saved_num_widgets>0){

                               alarms.cancel(newPending);
                            Intent widgetUpdate = new Intent(context, MyWidget.class);
                            widgetUpdate.setAction(AppWidgetManager.ACTION_APPWIDGET_UPDATE);
                            context.sendBroadcast(widgetUpdate);
                        }

                    }

                  }
                }, new IntentFilter(Intent.ACTION_SCREEN_ON));

Lets say that the last update happened at 10:00 am and the screen was off for 30 minutes. When the screen comes on, the widget gets updated for all the alarms stored for the pendingIntent at once. I want the widget update to happen only once when the screen come on again.

Initially I understood that AlarmManager.ELAPSED_REALTIME triggers when the devices wakes up from being idle.

I don't know why the alarm cancel don't work. Everything else works as expected.

By the way I have done performance tests on the 10 minute widget update on variety of devices and it is not at all a strain on available resources. Moreover the delivered the service does not even show up in the Battery Use monitor for Android devices.

Any help is much appreciated.

Answer 1

I've seen this as well. Changed it to use a broadcast receiver that receives SCREEN_OFF or SCREEN_ON and stopping/starting the Alarm service manually.

Not the answer you may of been wanting sorry :-)