Question

I would like to develop a widget for a existing android apps.

The only function i want is to display the variable i get from the apps.
I have developed a simple function to get variable from it but i don’t know how to update it when the apps is closed.

Or i have to write a service to get these variable?

package hkcsl.tabbedactivealarm;

import android.appwidget.AppWidgetManager;
import android.appwidget.AppWidgetProvider;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
import android.widget.RemoteViews;

public class AppWidgetExample extends AppWidgetProvider {   
@Override
public void onReceive(Context context, Intent intent) {

  super.onReceive(context, intent);     
  RemoteViews views = new RemoteViews(context.getPackageName(), R.layout.helloworld);
  String value1 = intent.getStringExtra("Value"); 
  views.setTextViewText(R.id.text, value1);
  AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(context);
  appWidgetManager.updateAppWidget(new ComponentName(context, AppWidgetExample.class), views);
   }
  }

Answer 1

if i understand the question –

Yes, it’s possible, but i believe that the update interval must be less frequent than once per minute. refer to this guide for a simple tutorial:

http://www.vogella.com/articles/AndroidWidgets/article.html#simplewidget

Yeah, your app needs a process that runs while your app is closed. so a background service or an AsyncTask or Thread would do. Background Service is your best choice

edit

okay i think i undersatnd better now. using that same link above, read section 4.

`appWidgetManager.updateAppWidget(widgetId, remoteViews);`

you only start 1 service, and the service takes care of updating values. if you want something special to happen upon the user exiting your app, you can override onDestroy()?

edit 2

use something like this in the XML:

<?xml version="1.0" encoding="utf-8"?>
<appwidget-provider 
      xmlns:android="http://schemas.android.com/apk/res/android"
    android:initialLayout="@layout/YOUR_LAYOUT"
    android:minHeight="72dp"
    android:minWidth="300dp"
    android:updatePeriodMillis="300000" >

</appwidget-provider> 

notice the updatePeriodMillis=300000

this was taken from section 3 of that article link above